Let’s assume that we need to setup VirtualBox VM with Windows XP and an old version of Microsoft Office. The machine must be used from everyone on a given number of Linux workstations. The workstations may work with LDAP and NFS/Cifs. The standard installation of the VM would be extremely space consuming and it would cost a lot of the personal life of the administrator.
I made an easy hack to solve this ( this is real setup in university labs).
Let’s install a standard local Windows XP virtual machine and permanently mount the local directories /home/trendafil and /media .
In this example, the home directory of the user will be mounted on X:\ on Windows and media will be Z:\ .
The important directories are out of the VM. So, the virtual machine will be runned from snapshot on every boot.
The next useful step is to move the default user profile outside the VM. I don’t need something different than My Documents but in other cases, everything from the profile can be exported to /home, outside the VM. So, open “regedit” in Windows and go to the
1
HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\Shell User Folders
and change the key “My Documents” to X:\
Turn off the VM and create an empty snapshot
Next, move the VM from ~/VirtualBox VMs to ~/.config/VirtualBox if it’s the official VirtualBox edition or ~/.VirtualBox for the open source edition from the Ubuntu repositories.
Open the file ~/.config/VirtualBox/VirtualBox.xml and clean it from the needless stuff:
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<ExtraDataItem name="GUI/RecentFolderHD"......;
<ExtraDataItem name="GUI/RecentListHD" ....... and etc..
Change the location of the VM and replace your username with “CURRENTUSR” everywhere inside the file, like this:
Create the directory /var/vbox/ and then move the harddisk image from ~/.VirtualBox/WinXp/winxp.vmdk to /var/vbox .
Then, move the whole ~/.VirtualBox or ~/.config/VirtualBox to /var/vbox
Install Zenity if it’s not installed:
1
$ sudo apt-get install zenity
Download this file and put it on /usr/local/bin/startwin:
and make it executable:
1
# chmod +x /usr/local/bin/startwin
It should work now. Every user of the system can start the VM from the script.
Additionaly, you can create a desktop enry.
First, find an ugly Window$ logo with an open license and put it on /usr/share/icons/win.png. Then, create the file /usr/share/applications/startwin.desktop with this content:
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[Desktop Entry]
Encoding=UTF-8
Version=1.0
Name=Windows XP
GenericName=Windows XP
Type=Application
Exec=/usr/lcal/bin/startwin
TryExec=/usr/local/bin/startwin
Icon=/usr/share/icons/win.png
Categories=Emulator;System;Application;
Comment=WindowsXP VirtualBox WM
Recently I’ve been playing around with a
Samsung Gear Fit
and while the hardware seems good I’m a bit disapointed on the software side.
There is at least one bug which is clearly visible - pedometer counts calories twice
when it’s on and exercise mode is started.
How to test:
Start the Pedometer app and record any initial readings;
Walk a fixed distance and at the end record all readings;
Now go back to the Exercise app and select a Walking
exercise from the menu. Tap Start;
Walk back the same distance/road as before. At the end of the journey
stop the walking exercise and record all readings.
Expected results:
At the end of the trip I expect to see roughly the same calories burned
for both directions.
Actual results:
The return trip counted twice as many calories compared to the forward trip.
Here’s some actual data to prove it:
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+--------------------------+----------+----------------+---------+-------------+---------+
| | Initial | Forward trip | | Return trip | |
| | Readings | Pedometer only | Delta | Pedometer & | Delta |
| | | | | Exercise | |
+--------------------------+----------+----------------+---------+-------------+---------+
| Total Steps | 14409 st | 14798 st | 389 st | 15246 st | 448 st |
+--------------------------+----------+----------------+---------+-------------+---------+
| Total Distance | 12,19 km | 12,52 km | 0,33 km | 12,90 km | 0,38 km |
+--------------------------+----------+----------------+---------+-------------+---------+
| Cal burned via Pedometer | 731 Cal | 751 Cal | 20 Cal | 772 Cal | 21 Cal |
+--------------------------+----------+----------------+=========+-------------+=========+
| Cal burned via Exercise | 439 Cal | 439 Cal | 0 | 460 Cal | 21 Cal |
+--------------------------+----------+----------------+---------+-------------+=========+
| Total calories burned | 1170 Cal | 1190 Cal | 20 cal | 1232 Cal | 42 Cal |
+--------------------------+----------+----------------+=========+-------------+=========+
Note: Data values above were taken from Samsung’s S Health app which is easier to work with
instead of the Gear Fit itself.
The problem is that both apps are accessing the sensor simultaneously and not aware of each other.
In theory it should be relatively easy to block access of one app while the other is running but
that may not be so easy to implement on the limited platform the Gear Fit is.
Did you know that the popular MyFitnessPal application can’t scan barcodes
printed on curved surfaces? The above barcode fails to scan because it is
printed on a metal can full of roasted almonds :). In contrast the
Barcode Scanner from ZXing Team understands it just fine. My bet is
MyFitnessPal uses less advanced barcode scanning library. Judging from
the visual clues in the app the issue is between 6 and 0 where white space is wider.
Despite being a bit blurry this second barcode is printed on a flat surface and
is understood by both MyFitnessPal and “ZXing Barcode Scanner”.
NOTE I get the same results regardless if I try to scan the actual barcode
printed on packaging, a picture from a mobile device screen or these two images
from the laptop screen.
MyFitnessPal also has problems with duplicate barcodes! Barcodes are not unique
and many producers use the same code for multiple products. I’ve seen this in the
case of two different varieties of salami from the same manufacturer on the good end
and two different products produced across the world (eggs and popcorn) on the
extreme end.
Once the user scans their barcodes and establish that the existing information is
not correct they can Create a Food and update the calories database. This is then
synced back to MyFitnesPal servers and overrides any existing information. When the same
barcode is scanned for the second time only the new DB entry is visible.
How to reproduce:
Scan an existing barcode and enter it to MFP database if not already there;
Scan the same barcode one more time and pretend the information is not correct;
Click the Create a Food button and fill-in the fields. For example use a
different food name to distinguish between the two database entries. Save!
From another device with different account (to verify information in DB)
scan the same barcode again.
Actual results:
The last entered information is shown.
Expected results:
User is shown both DB records and can select between them.
Happy new year everyone. During the holidays I’ve discovered several interesting
bugs which will be revealed in this blog. Starting today with a bug in the popular
game Candy Crush Saga.
In level 80 one teleport is still open but the chocolates are blocking the rest.
The game has ended but candies keep flowing through the teleport and the level doesn’t exit.
My guess is that the game logic is missing a check whether or not it will go into an endless loop.
This bug seems to be generic for the entire game. It pops up also on
level 137 in the Owl part of the game (recorded by somebody else):
Few days ago I’ve resurrected my BlackBerry Z10 only to find out that it kills
my WiFi router shortly after connecting to the network.
It looks like many people are having the same problem with BlackBerry but most forum
threads don’t offer a meaningful solution so I did some tests.
Everything works fine when WiFi mode is set to either 11bgn mixed or 11n only and
WiFi security is disabled.
When using WPA2/Personal security mode and AES encryption the problem occurs
regardless of which WiFi mode is used. There is another type of encryption called TKIP
but the device itself warns that this is not supported by the 802.11n specification
(all my devices use it anyway).
So to recap:
BlackBerry Z10 causes my TP-Link router to die if using WPA2/Personal security with
AES Encryption. Switching to open network with MAC address filtering works fine!
I haven’t had the time to upgrade the firmware of this router and see if the problem persists.
Most likely I’ll just go ahead and flash it with OpenWRT.
Security and usability are almost never mutually inclusive concepts. Expecially in the cloud apps. They are really useful but the security is controversial. Highest security means no internet and even computers..
In our company, we use OwnCloud. It’s an open source application for cloud file synchronization, like DropBox and Google Drive.
OwnCloud can be used with private SSL keys but it’s still not secure because it’s written on PHP. I make updates regularly but a security flaw may be undiscovered for weeks or even years (Heartbleed and Shellshock for example).
VPN is not a solution because it separates from the point in the middle when OwnCloud is used on a smartphone or tablet.
I wrote a small application for usage inside our company. It generates an unique string from the filename and the metadata of the office documents.
The string can be set for a password of the document. This is not a strong security solution, but a small accurance. It’s a matter of CPU time for the password to be cracked. But it’s even closer to the point in the middle because nobody have to remember the passwords. Maybe it would be good if it uses Kde’s Wallet, Gnome Keyring or something other in Windows, but it’s still under consideration.
In this post I’m gonna explain you how to deploy really fast and cheap cluster of Linux Containers. I use the same setup in a production enviroment for a big accounting software (10GB++ of MySQL).
Why LXC? Because it is Über-cool! Compared to the Hardware Virtualization, the runtime performance is near the bare metal speeds. Operations like starting/stopping of the system or clonning and snapshots are really fast. There’s no virtual BIOS, boot loader and kernel. A given number of containers can share the same system resources as they are installed on the same bare metal system and are still isolated. It’s really lightweight and flexible. You can containerize everything – a whole system or a single application. Stéphane Graber has a really good blog post series about LXC.
DRBD will provide the block device replication between the servers. Let’s think of it as a RAID1 array between the two machines. It can work as master-master or master-slave. The master-master setup is more risky and it works only with shared cluster file systems (GFS, OCFS2 or GlusterFS). I don’t have the balls to use it master-master on two nodes for VM’s and containers, so in this setup I’ll use master-slave. The difference is that when an array is promoted as slave on a given machine, it cannot be accessed.
Btrfs is the new hipster in town :) It’s a new “copy on write” file system and logical volume manager for the Linux kernel. It has many similarities with the ZFS, but is part of the kernel. Snapshotting and cloning of the containers are easier with Btrfs. It can make snapshots and subvolumes of a given directory and mount it as another block device. Note that it’s already stable but still has problems. Stable filesystem for production environment must be 7+ years old! I bet on the backups :)
So, let’s suppose that we have two identical machines with this sample configuration:
Intel Xeon E5;
16GB of RAM;
500GB RAID1 array –> /dev/sda;
2x 1TB RAID10 arrays –> /dev/sdb and /dev/sdc;
Standart gigabit interface/s –> eth0;
10GB Ethernet interface, linked between the machines –> eth1;
First, install standart Ubuntu LTS on the RAID1 arrays and don’t touch the RAID10.
The Network
The containers will use veth network, so we need to create a bridge:
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sudo apt-get install bridge-utils
Our internet network will be 10.1.0.0/24 and our peer network – 10.0.254.0/30.
So, /etc/network/interfaces of node1 will be:
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auto lo
iface lo inet loopback
auto eth0
iface eth0 inet manual
auto br0
iface br0 inet static
address 10.1.0.5
netmask 255.255.255.0
gateway 10.1.0.1 #ok, let's put a gateway:) bridge_ports eth0
bridge_fd 0
bridge_stp off
bridge_maxwait 0
auto eth1
iface eth1 inet static
address 10.0.254.1
netmask 255.255.255.252
And for node2:
12345678910111213
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 10.1.0.6
netmask 255.255.255.0
gateway 10.1.0.1
auto eth1
iface eth1 inet static
address 10.0.254.2
netmask 255.255.255.252
… and the hostnames in /etc/hosts. DRBD works with hostnames. On the both machines:
Be sure to check the official documentation. The setup of DRBD is really complex and personal, depending on the hardware, the network and the required results.
Installing drbd on the both machines
1
sudo apt-get install drbd8-utils
Load the kernel module
1
sudo apt-get install drbd8-utils
The time must be in sync for the DRBD. So, install NTP clien:
on the both machines
1
sudo apt-get install ntp ntpdate
On this tutorial I will use the whole RAID10 arrays. It would be better if we completely erase the partition tables (if any) and start from scratch with a new partition table and just one, empty partition.
Erase the partition tables on the both of the nodes. I expect the drive numbers to be identical because the hardware is the same:
Let’s take a look at the partition layout of the drives. For the example in the tutorial, I use a qcow2 image, mounted on my laptop and some information like the disk identifier and model will not appear. Also, sda is not sized for server usage.
The system should be ready for production. Let’s create the first template. In Node1, for example:
Only on node 1
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lxc-create -t ubuntu -n mysql -B btrfs
Without “-b btrfs”, the container’s backing store will be treated as a filesystem directory and the snapshots and clones will be created with simple file copy.
Copy with scp the files /srv/store1/containers/mysql/config and /srv/store1/containers/mysql/fstab to the according directory in node2 – /srv/store2/containers/mysql/ . This is necessary for the failover setup. If, for example, node1 fails, the container “mysql” will be easily run from node2 if the /dev/drbd0* is promoted as a primary there:
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drbdadm primary r1
mount /dev/drbd0 /srv/store1
lxc-start -n mysql -d
Snapshot can be created with:
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lxc-snapshot -n mysql
lxc-snapshot -n mysql -L #will list the snapshotslxc-snapshot -n mysql -d snap0 # will delete snap0
There is a lot of documentation available about the LXC commands and configuration options. I’ll post a small howto anyway. I’m still writing backup scripts with the LXC api. If they are done, I’ll post documentation about the backup.
After I figured out that
Celery is rather slow
I moved on to test another part of my environment - a web proxy server.
The test here compares two proxy
implementations
- one with Python Twisted,
the other in Go. The backend is a simple web server written in Go, which is
probably the fastest thing when it comes to serving HTML.
The test content is a snapshot of the front page of this blog taken few days ago.
The system is a standard Lenovo X220 laptop, with Intel Core i7 CPU, with 4 cores.
The measurement instrument is the popular wrk tool with a
custom Lua script to redirect the requests through the proxy.
All tests were repeated several times, only the best results are shown here.
I’ve taken time between the tests in order for all open TCP ports to close.
I’ve also observed the number of open ports (e.g. sockets) using netstat.
Baseline
Using wrk against the web server in Go yields around 30000 requests per second
with an average of 2000 TCP ports in use:
$ ./wrk -c1000 -t20 -d30s http://127.0.0.1:8000/atodorov.html
Running 30s test @ http://127.0.0.1:8000/atodorov.html
20 threads and 1000 connections
Thread Stats Avg Stdev Max +/- Stdev
Latency 304.43ms 518.27ms 1.47s 82.69%
Req/Sec 1.72k 2.45k 17.63k 88.70%
1016810 requests in 29.97s, 34.73GB read
Non-2xx or 3xx responses: 685544
Requests/sec: 33928.41
Transfer/sec: 1.16GB
Python Twisted
The Twisted implementation
performs at little over 1000 reqs/sec with an average TCP port use between 20000 and 30000:
First I’ve run several 30 seconds tests and performance was around 8000 req/sec
with around 20000 ports used (most of them remain in TIME_WAIT state for a while).
Then I’ve modified proxy.go to make use of all available CPUs on the system and let
the test run for 5 minutes.
Performance peaked at 10000 req/sec. TCP port usage initially rose to around 30000
but rapidly dropped and stayed around 3000. Both webserver.go and proxy.go were
printing the following messages on the console:
2014/11/18 21:53:06 http: Accept error: accept tcp [::]:9090: too many open files; retrying in 1s
Conclusion
There’s no doubt that Go is blazingly fast compared to Python and I’m most likely to use it
further in my experiments. Still I didn’t expect a 3x difference in performance from webserver vs. proxy.
Another thing that worries me is the huge number of open TCP ports which then drops and stays
consistent over time and the error messages from both webserver and proxy (maybe per process sockets limit).
At the moment I’m not aware of the internal workings of neither wrk, nor
Go itself, nor the goproxy library to make conclusion if this is a bad thing or expected.
I’m eager to hear what others think in the comments. Thanks!
Update 2015-01-27
I have retested with PyPy but on a different system so I’m giving all the test results
on it as well. /proc/cpuinfo says we have 16 x Intel(R) Xeon(R) CPU E5-2450L 0 @ 1.80GHz
CPUs.
As seen Go proxy is slower than the Go server by factor of 2.
Python proxy is slower by than the Go server by factor of 20.
These results are similar to previous ones so I don’t think PyPy
makes any significant difference.
Few times recently I’ve seen people using an HTTP benchmarking tool called
wrk and decided to give it a try. It is a very cool
instrument but didn’t fit my use case perfectly. What I needed is to be able to
redirect the connection through a web proxy and measure how much the proxy
slows down things compared to hitting the web server directly with wrk.
In other words - how fast is the proxy server.
How does a proxy work
I’ve examined the source code of two proxies (one in Python and another one in Go)
and what happens is this:
The proxy server starts listening to a TCP port
A client (e.g. the browser) sends the request using an absolute URL (GET http://example.com/about.html)
Instead of connecting directly to the web server behind example.com the client connects to the proxy
The proxy server does connect to example.com directly, reads the response and delivers it back to
the client.
Proxy in wrk
Luckily wrk supports the execution of Lua scripts so we can make a
simple script like this:
init = function(args)
target_url = args[1] -- proxy needs absolute URL
end
request = function()
return wrk.format("GET", target_url)
end
Then update your command line to something like this:
This causes wrk to connect to our proxy server but instead issue GET requests for another URL.
Depending on how your proxy works you may need to add the Host: example.com header as well.
Now let’s do some testing.
Ten days ago the regular HackFMI competition was held.
This year they tried sending SMS notifications to all participants which was powered
by Twilio both in terms of infrastructure and cost.
Twilio provided a 20$ upgrade code valid in the next 6 months for all new accounts.
This was officially announced at the opening ceremony (although at the last possible time) of the
competition, however no teams decided to incorporate SMS/Voice into their games.
I’m a little disappointed by this fact.
In terms of software a simple Django app
was used. It is by no means production ready but does the job and was quick to write.
A little over 300 messages were sent with number distribution as follows:
Mtel - 166
Globul - 86
Vivacom - 50
The total price for Mtel and Globul messages is roughly the same because sending
SMS to Globul via Twilio is as twice expensive. The total sums up to about 25 $.
HackFMI team used two accounts to send the messages - one using the provided
20$ upgrade code from Twilio and the second one was mine.
In the second part of this article we’ve seen
how slow Celery actually is.
Now let’s explore what happens inside and see if we can’t speed things up.
I’ve used pycallgraph to create
call graph visualizations of my application. It has the nice feature to also show
execution time and use different colors for fast and slow operations.
producer is always None because delay() doesn’t pass it as argument.
I’ve tried passing it explicitly to apply_async() as so:
from djapp.celery import *
# app = debug_task._get_app() # if not defined in djapp.celery
producer = app.amqp.producer_pool.acquire(block=True)
debug_task.apply_async(producer=producer)
However this doesn’t speedup anything. If we replace the above code block like this:
349 with producer as P:
it blows up on the second iteration because producer and its channel is already None !?!
If you are unfamiliar with the with statement in Python please read
this article. In short the with statement is
a compact way of writing try/finally. The underlying kombu.messaging.Producer class does a
self.release() on exit of the with statement.
I also tried killing the with statement and using producer directly but with limited success. While
it was not released(was non None) on subsequent iterations the memory usage grew much more and there
wasn’t any performance boost.
Conclusion
The with statement is used throughout both Celery and Kombu and I’m not at all sure if
there’s a mechanism for keep-alive connections. My time constraints are limited and I’ll probably
not spend anymore time on this problem soon.
Since my use case involves task producer and consumers on localhost I’ll try to workaround the
current limitations by using Kombu directly
(see this gist) with a transport that
uses either a UNIX domain socket or a name pipe (FIFO) file.
In the first part of this
post I looked at a few celery backends and discovered they didn’t meet my needs.
Why is the Celery stack slow? How slow is it actually?
How slow is Celery in practice
Queue: 500`000 msg/sec
Kombu: 14`000 msg/sec
Celery: 2`000 msg/sec
Detailed test description
There are three main components of the Celery stack:
Celery itself
Kombu which handles the transport layer
Python Queue()’s underlying everything
Using the Queue and Kombu tests
run for 1 000 000 messages I got the following results:
Raw Python Queue: Msgs per sec: 500`000
Raw Kombu without Celery where kombu/utils/__init__.py:uuid() is set to return 0
with json serializer: Msgs per sec: 5`988
with pickle serializer: Msgs per sec: 12`820
with the custom mem_serializer from part 1:
Msgs per sec: 14`492
Note: when the test is executed with 100K messages mem_serializer yielded
25`000 msg/sec then the performance is saturated. I’ve observed similar behavior
with raw Python Queue()’s. I saw some cache buffers being managed internally to avoid OOM
exceptions. This is probably the main reason performance becomes saturated over a longer
execution.
Using celery_load_test.py modified to
loop 1 000 000 times I got 1908.0 tasks created per sec.
Another interesting this worth outlining - in the kombu test there are these lines:
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with producers[connection].acquire(block=True) as producer:
for j in range(1000000):
If we swap them the performance drops down to 3875 msg/sec which is comparable with the
Celery results. Indeed inside Celery there’s the same with producer.acquire(block=True)
construct which is executed every time a new task is published. Next I will be looking
into this to figure out exactly where the slowliness comes from.
I’m working on an application which fires a lot of Celery tasks - the more
the better! Unfortunately Celery backends seem to be rather slow :(.
Using the celery_load_test.py
command for Django I was able to capture some metrics:
Amazon SQS backend: 2 or 3 tasks/sec
Filesystem backend: 2000 - 2500 tasks/sec
Memory backend: around 3000 tasks/sec
Not bad but I need in the order of 10000 tasks created per sec!
The other noticeable thing is that memory backend isn’t much faster compared to
the filesystem one! NB: all of these backends actually come from the kombu package.
Why is Celery slow ?
Using celery_load_test.py together with
cProfile I
was able to pin-point some problematic areas:
kombu/transports/virtual/__init__.py: class Channel.basic_publish() - does
self.encode_body() into base64 encoded string. Fixed with custom transport backend
I called fastmemory which redefines the body_encoding property:
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@cached_propertydefbody_encoding(self):returnNone
Celery uses json or pickle (or other) serializers to serialize the data.
While json yields between 2000-3000 tasks/sec, pickle does around 3500 tasks/sec.
Replacing with a custom serializer which just returns
the objects (since we read/write from/to memory) yields about 4000 tasks/sec tops:
kombu/utils/__init__.py: def uuid() - generates random unique identifiers
which is a slow operation. Replacing it with return "00000000" boosts performance
to 7000 tasks/sec.
It’s clear that a constant UUID is not of any practical use but serves well to illustrate
how much does this function affect performance.
Note:
Subsequent executions of celery_load_test seem to report degraded performance even with
the most optimized transport backend. I’m not sure why is this. One possibility is the random
UUID usage in other parts of the Celery/Kombu stack which drains entropy on the system and
generating more random numbers becomes slower. If you know better please tell me!
I will be looking for a better understanding
of these IDs in Celery and hope to be able to produce a faster uuid() function. Then I’ll be
exploring the transport stack even more in order to reach the goal of 10000 tasks/sec.
If you have any suggestions or pointers please share them in the comments.
In the example above (actual application) first line is kombu’s
abstract.py: class Object(object).__init__()
and the second one is Python’s
uuid.py: class UUID().__init__().
Prompted by Rado’s post about
Mtel not fixing a business customer Internet connection
I want to tell you a story about how the big company totally fucked up their
online invoice system and give you a few more hints about how stupidity
reigns supreme even in big companies, especially in Bulgaria.
I’ve never received a paper invoice for my phone bill and used the website to access any information
about my bills and calls duration, etc. The problem is that I ported my number to another operator.
Porting a number away from Mtel automatically cuts access to your previous invoices online
The problem in technical terms
This is a tech blog so let’s be technical. Users can register at Mtel’s website via
username and password. If they are customers then they can add their numbers to their
profile. Once the number is verified (via SMS code), the user has access to additional services
one of which is online invoices and monthly usage reports.
Migrating away to another operator “erases” your number from the system but
this is not true actually. All the information is still there because they can give me
print outs if I pay all the extra fees and simply because no business will voluntarily
erase their database records.
The genius who designed the if-number-migrated-then-delete-from-user-profile-and-cut-off-access
business process/software implementation is the biggest idiot in the world.
How Mtel handled my complaint
My request for
explanation (see below) was answered with a nice letter, basically telling me to piss off. None of my
questions were answered. To make things worse they want to charge extra fees for detailed print outs.
What I’ve asked for:
To be granted access back to all of my invoices online. Not only I paid for them but this
is something of a personal information;
To be given copies of my last 5 invoices, preferably via email;
To be given explanation why my online access to previous invoices was cut off;
Mtel to stop doing this and allow access to online invoices for everyone of their past
or current customers;
I’ve also told them I’m available to help them fix their system if they don’t have
the resources to do so (hint, hint: it’s an if-then condition or something very close I bet).
A copy of my complaint and the response to it (in Bulgarian only):
A month ago one of my startups Difio stopped working forever.
This is the story of how to go about shutting down a working
web service and not about why it came around to this.
Step #1: Disable new registrations
You obviously need to make sure new customers
arriving at your web site will not sing up to only find the service is
shutting down later.
Disable whatever sign-on/registration system you have in place
but leave currently registered users to login as they wish.
Step #2: Disable payments
Difio had paying customers, just not enough of them and it was based on
a subscription model which was automatically renewed without any interaction
from the customer.
The first thing I did was to disable all payments for the service which
was quite easy (just a few comments) because Difio used an external payment
processor.
Next thing was to go through all subscriptions that were still active and
cancel them. This prevented the payment processor to automatically charge
the customers next time their subscription renewal was due.
Because all subscriptions were charged in advance and when canceled were
still considered active (due to expire at some later date) Difio had to
keep operating at least one month after all subscriptions have been canceled.
Step #3: Notify all customers that you are shutting down
I scheduled this to happen right after the last subscription was canceled.
An email to everyone who registered to the website and a blog post should work
for most startups. See ours here.
Make sure to provide a gratis period if necessary. Difio had a gratis period
of one month after the shutdown announcement.
Step #4: Disable all external triggers
Difio was a complex piece of software which relied on external triggers like
web hooks and repetitive tasks executed by cron.
Disabling these will prevent external services or hosting providers
getting errors about your URLs not being accessible. It is just polite
to do so.
You may want to keep these still operational during the gratis period
before the physical shutdown or disable them straight away. In Difio’s
case they were left operational because there were customers who have paid
in advance and relied on this functionality.
Step #5: Prepare your ‘Service Disabled’ banner
You will probably want to let people know why something isn’t working
as it used (or is expected) to be. A simple page explaining that
you’re going to shut down should be enough.
Difio required the user to be logged in to see most of the website.
This made it very easy to redirect everything to the same page.
A few more places were linking to public URLs which were manually rewritten
to point to the same ‘Service Disabled’ page.
It is the same page used previously to redirect new registrations to.
Step #6: Terminate all processing resources
Difio used both AWS EC2 instances and an OpenShift PaaS instance to do its
processing. Simply terminating all of them was enough. The only thing left
is a couple of static HTML pages behind the domain.
Step #7: Database archival
The last thing you need to do is archive your database. Although the
startup is out of business already you have gathered additional information
which may come handy at a later time.
Difio didn’t collect any personal information about its users, except email
and didn’t store financial information either. This made it safe to just make
a backup of the database and leave it lurking around on disk.
However beware
if you have collected personal and/or financial information from your customers.
You may want to erase/anonymize some of it before doing your backups and
probably safeguard them from unauthorized access.
That’s it, your startup is officially dead now! Let me know if I’ve missed
something in the comments below.
Many entrepreneurs who build great products simply don’t have a good distribution strategy.
Traction: A Startup Guide to Getting Customers
introduces startup founders and employees to the “Bullseye Framework,”
a five-step process successful companies use to get traction.
This framework helps founders find the marketing channel that will be key to unlocking the next stage of growth.
Too often, startups building a product struggle with traction once they launch.
This struggle has startups trying random tactics - some ads, a blog post or two - in an unstructured way that leads to failure.
Traction shows readers how to systematically approach marketing, and covers how successful businesses have grown through each of
the following 19 channels:
Viral Marketing
Public Relations (PR)
Unconventional PR
Search Engine Marketing (SEM)
Social and Display Ads
Offline Ads
Search Engine Optimization (SEO)
Content Marketing
Email Marketing
Engineering as Marketing
Target Market Blogs
Business Development (BD)
Sales
Affiliate Programs
Existing Platforms
Trade Shows
Offline Events
Speaking Engagements
Community Building
The book is very easy to read and full of practical advice which should serve as a starting point and give you
more ideas how to approach a particular distribution channel. It took me two days to read and
I already had some ideas to test even before reading the whole of it. My next steps are to apply the principles
to my current startup Obuvki 41 Plus and a future one I have in mind.
To anyone building a startup of any kind I would recommend the following selection of books:
After a bit more than 2 years it was high time to do new release to adapt to current Fedora and Eclipse releases. Most of the changes in this release were towards cleaning and simplifying the codebase hoping for faster releases but there are some important feature changes like:
Fedorapackager requires Java 8 now.
Allow users to clone multiple projects at once.
Fix changelog parsing for Bodhi
Make use of /etc/rpkg/fedpkg.conf
Modified Fedora Packager Koji properties page
Reduce logging noise.
Enable rpmlint and rpm natures by default.
Tagging is no longer used with Git.
Shorter menu labels.
Fixed JsonNull error when pushing bodhi update
Eval NVRs when Bodhi updating
Eval the name to not fail on sclized packages.
Bodhi authenticate when pushing review fix.
Bodhi dialog cleanup.
Make perspective switch remember previous choice.
Let the console name has the package (srpm) name in it.
Remove expectation of the existance of an ssh key.
Updated packages are available in Rawhide and Fedora 21 updates-testing.
Whenever you find yourself on the side of the majority, it is time to pause and reflect.
The book starts with a story about the Tango World Championship semifinals in
Argentina and poses the question
“What on earth would I be doing right now, if I hadn’t left my job and the U.S. over a year ago?”
Can you answer this? Keep reading!
Step 1: Definition
Tim defines two groups of people. The Deferrers, those who save it all for the
end only to find that life has passed them by and the New Rich.
* The employee who rearranges his schedule and negotiates a remote work agreement to achieve 90% of the results in one-tenth of the time, which frees him to practice cross-country skiing and take road trips with his family two weeks per month.
* The business owner who eliminates the least profitable customers and projects, outsources all operations entirely, and travels the world collecting rare documents, all while working remotely on a website to showcase her own illustration work.
* The student who elects to risk it all—which is nothing—to establish an online video rental service that delivers $5,000 per month in income from a small niche of Blu-ray aficionados, a two-hour-per-week side project that allows him to work full-time as an animal rights lobbyist.
The possibilities are endless. What defines the New Rich is their unrestricted mobility
and availability of free time! Money alone doesn’t count anymore. Its practical value is
multiplied by the what, when, where and with whom you do what you do.
From that point of view earning less money but spending far less time on that is
much more powerful than working 80 hours per week for a million dollars.
Step 2: Elimination
One does not accumulate but eliminate. It is not daily increase but daily decrease. The height of cultivation always runs to simplicity.
In this chapter Tim talks about developing selective ignorance of information,
the 80-20 Pareto principle,
gives tips for faster reading and battling interruption like checking your e-mail
and smart phone.
Step 3: Automation
Outsourcing and technical automation are the keys here but there is more.
Tim talks about income autopilot - designing your income sources in such a way
so that they don’t consume much of your time and continue to produce income
even after the initial time investment.
Think about the following: working a 9-to-5 job yields an income only during
office hours. Having written a book yields income whenever a copy is sold, which
is while you’re asleep and long after the initial time investment required to
write the book.
Then you can diversify your income streams and voila - you’re making money
automatically :)
Tim also refers to the business management side of things. Why become the
manager when you can be the owner of the business ? It’s kind of hard to
let virtual assistants run your business and resolve issues for you but that
frees up your time which is more valuable.
In between he also mentions why as a business you should keep prices high!
Counter intuitive, isn’t it?
This is easier said than done but I’ve been working on it for the last couple
of years and its starting to take shape nicely so there’s truth to it.
Step 4: Liberation
This is the chapter which helps you escape the 9-5 office hours through some
interesting techniques. This is not only for freelancers like myself but also
for the regular employee. One of the principles is to ask for forgiveness,
not a permission (which will be denied anyway).
Another one boils down to:
Increase company investment into you so that the loss is greater if you quit,
e.g. corporate training;
Prove increased output offsite - call in sick Tuesday to Thursday but continue
working. Produce more and leave some sort of digital trail, emails, etc;
Prepare the quantifiable business benefit - you need to present remote working
as a good business decision and not a personal perk, for example you’ve managed to
bill more hours to your company’s customers. As explanation use removal of commute
and fewer distractions from the office noise;
Propose a revocable trial period - plan everything that will be said but play it
cool and casual. You want to avoid the impression that remote working will be something
permanent (for now). Find a relaxed afternoon and give it a shot!
Expand remote time by making sure you’re most productive on your days out of the
office and if need be lower the productivity inside the office a bit. Then give it
a shot for a longer trial period or more days working remotely;
There’s also another one called the hourglass approach, so named because you use a
long proof-of-concept up front to get a short remote agreement and then negotiate
back up to full-time out of the office.
I personally had it easier in terms of remote working. Before I became a contractor
I’ve been working with folks in the US to whom it doesn’t really matter whether I was
based in Czech Republic or in Bulgaria. Also I’ve been sick at that time and had an
important project to manage which all just played nicely in proving that I
can be productive in any location.
Then comes one of my favorite sections Killing Your Job. Boy you just have to read
this. Lots of people need to read this! Everything you are afraid of and keeps you from
quitting your job is total bulshit. There are always options. It might be emotionally
difficult, but you won’t starve!
Extended edition
This extended edition of the book completes with blog articles and bonus sections
like Killing Your BlackBerry.
I’m a 37-year-old Subway franchisee owning and operating 13 stores. Been doing this for seven years. Prior to reading 4HWW I was KING at W4W (translate: work for work’s sake) … Crunched my “always open” workweek into four days and 20 hours. I immediately began taking Mondays OFF, giving me a nice three-day weekend. Tuesday to Friday I work 11 A.M.–4 P.M. (20 hours per week). … I was forced to appraise everything through the 80/20 filter and found that 50% of the 80% was pure crap and the other 50% of the 80% could be done by someone on my payroll. … I still carry portable e-mail but I’ve killed “auto-sync”. Now it’s on a Tues–Fri, 11 A.M.–4 P.M. schedule. … My e-mail autoresponder eliminated 50% of my e-mail within two weeks as people sending me meaningless crap got fed up looking at my autoresponder and stopped including me.
How to Win Friends & Influence People
by Dale Carnegie teaches you how to deal with people. The book briefly explains
some easy to use principles, why and how they work and then provides tons of
real life examples behind those principles. This book is a must for everyone but
especially parents and teachers and folks in sales, management or business leaders.
I will only highlight the key points. What follows are direct quotes from the book.
Part One: Fundamental Techniques in Handling People
‘If You Want to Gather Honey, Don’t Kick Over the Beehive’ - PRINCIPLE 1: Don’t criticise, condemn or complain.
The Big Secret of Dealing with People - PRINCIPLE 2: Give honest and sincere appreciation.
‘He Who Can Do This Has the Whole World with Him. He Who Cannot Walks a Lonely Way’ -
PRINCIPLE 3: Arouse in the other person an eager want.
Part Two: Six Ways to Make People Like You
Do This and You’ll Be Welcome Anywhere - PRINCIPLE 1: Become genuinely interested in other people.
A Simple Way to Make a Good First Impression - PRINCIPLE 2: Smile.
If You Don’t Do This, You Are Headed for Trouble - PRINCIPLE 3:
Remember that a person’s name is to that person the sweetest and most important sound in any language.
An Easy Way to Become a Good Conversationalist - PRINCIPLE 4: Be a good listener.
Encourage others to talk about themselves.
How to Interest People - PRINCIPLE 5: Talk in terms of the other person’s interests.
How to Make People Like You Instantly - PRINCIPLE 6: Make the other person feel important – and do it sincerely.
Part Three: How to Win People to Your Way of Thinking
You Can’t Win an Argument - PRINCIPLE 1: The only way to get the best of an argument is to avoid it.
A Sure Way of Making Enemies – and How to Avoid It - PRINCIPLE 2: Show respect for the other person’s opinions.
Never say, ‘You’re wrong’.
If You’re Wrong, Admit It - PRINCIPLE 3: If you are wrong, admit it quickly and emphatically.
A Drop of Honey - PRINCIPLE 4: Begin in a friendly way.
The Secret of Socrates - PRINCIPLE 5: Get the other person saying ‘yes, yes’ immediately.
The Safety Valve in Handling Complaints - PRINCIPLE 6: Let the other person do a great deal of the talking.
How to Get Cooperation - PRINCIPLE 7: Let the other person feel that the idea is his or hers.
A Formula That Will Work Wonders for You - PRINCIPLE 8: Try honestly to see things from the other person’s point of view.
What Everybody Wants - PRINCIPLE 9: Be sympathetic with the other person’s ideas and desires.
An Appeal That Everybody Likes - PRINCIPLE 10: Appeal to the nobler motives.
The Movies Do It. TV Does It. Why Don’t You Do It? - PRINCIPLE 11: Dramatise your ideas.
When Nothing Else Works, Try This - PRINCIPLE 12: Throw down a challenge.
Part Four: Be a Leader: How to Change People Without Giving Offense or Arousing Resentment
If You Must Find Fault, This Is the Way to Begin - PRINCIPLE 1: Begin with praise and honest appreciation.
How to Criticise – and Not Be Hated for It - PRINCIPLE 2: Call attention to people’s mistakes indirectly.
Talk About Your Own Mistakes First - PRINCIPLE 3: Talk about your own mistakes before criticising the other person.
No One Likes to Take Orders - PRINCIPLE 4: Ask questions instead of giving direct orders.
Let the Other Person Save Face - PRINCIPLE 5: Let the other person save face.
How to Spur People On to Success - PRINCIPLE 6: Praise the slightest improvement and
praise every improvement. Be ‘hearty in your approbation and lavish in your praise’.
Give a Dog a Good Name - PRINCIPLE 7: Give the other person a fine reputation to live up to.
Make the Fault Seem Easy to Correct - PRINCIPLE 8: Use encouragement. Make the fault seem easy to correct.
Making People Glad to Do What You Want - PRINCIPLE 9: Make the other person happy about doing the thing you suggest.
This is a quick status update for one of the pieces of
Fedora QA infrastructure
and mostly a self-note.
Previously to control the kickstart configuration used during installation in Beaker one
had to either modify the job XML in Beaker or use SNAKE (bkr workflow-snake) to render
a kickstart configuration from a Python template.
SNAKE presented challenges when deploying and using
beaker.fedoraproject.org and is
virtually unmaintained.
I present the new bkr workflow-installer-test which uses Jinja2 templates to
generate a kickstart configuration when provisioning the system. This is already
available in beaker-client-0.17.1.
The templates make use of all Jinja2 features (as far as I can tell) so you can create
very complex ones. You can even include snippets from one template into another if required.
The standard context that is passed to the template is:
DISTRO - if specified, the distro name
FAMILY - as returned by Beaker server, e.g. RedHatEnterpriseLinux6
OS_MAJOR and OS_MINOR - also taken from Beaker server. e.g. OS_MAJOR=6 and OS_MINOR=5 for RHEL 6.5
VARIANT - if specified
ARCH - CPU architecture like x86_64
any parameters passed to the test job with --taskparam. They are processed last and can override previous values.
Installation related tests at fedora-beaker-tests
have been updated with a ks.cfg.tmpl templates to use with this new workflow.
This workflow also has the ability to return boot arguments for the installer if needed.
If any, they should be defined in a {% block kernel_options %}{% endblock %}
block inside the template. A simpler variant is to define a comment line that stars with
## kernel_options:
There are still a few issues which need to be fixed before beaker.fedoraproject.org
can be used by the general public though. I will be writing another post about that
so stay tuned.
In my practice I like to use webhooks and integrate auxiliary services with
my internal processes or businesses. One of these is the collection of emails.
In this short article I’ll show you an example of how to collect email addresses
from the comments of a WordPress.com blog and the UserVoice feedback/ticketing system.
WordPress.com
For your WordPress.com blog from the Admin Dashboard navigate to
Settings -> Webhooks and add a new webhook with action comment_post
and fields comment_author, comment_author_email. A simple
Django view that handles the input is shown below.
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@csrf_exemptdefhook_wp_comment_post(request):ifnotrequest.POST:returnHttpResponse("Not a POST\n",content_type='text/plain',status=403)hook=request.POST.get("hook","")ifhook!="comment_post":returnHttpResponse("Go away\n",content_type='text/plain',status=403)name=request.POST.get("comment_author","")first_name=name.split(' ')[0]last_name=' '.join(name.split(' ')[1:])details={'first_name':first_name,'last_name':last_name,'email':request.POST.get("comment_author_email",""),}store_user_details(details)returnHttpResponse("OK\n",content_type='text/plain',status=200)
UserVoice
For UserVoice navigate to Admin Dashboard -> Settings -> Integrations ->
Service Hooks and add a custom web hook for the New Ticket notification.
Then use a sample code like that:
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@csrf_exemptdefhook_uservoice_new_ticket(request):ifnotrequest.POST:returnHttpResponse("Not a POST\n",content_type='text/plain',status=403)data=request.POST.get("data","")event=request.POST.get("event","")ifevent!="new_ticket":returnHttpResponse("Go away\n",content_type='text/plain',status=403)data=json.loads(data)details={'email':data['ticket']['contact']['email'],}store_user_details(details)returnHttpResponse("OK\n",content_type='text/plain',status=200)
store_user_details() is a function which handles the email/name received in the webhook,
possibly adding them to a database or anything else.
I find webhooks extremely easy to setup and develop and used them whenever they are
supported by the service provider. What other services do you use webhooks for? Please
share your story in the comments.
I’m starting a new series where I will share my thoughts about software design,
usability and other related topics with examples of items I like or dislike.
I’ve
written before
about the topic so consider this post as a sequel. I’m starting with couple of
examples from the mobile world. Plese use the comments to tell if there is something
that you particulary like or dislike in software or hardware design
(and apologies to my readers for not being able to post more frequently lately).
BlackBerry Camera Burst Feature vs. Android
BlackBerry 10 Camera’s burst mode is well made in my opinion. It is capable of
taking thousands of pictures and saving the to disk without interruption. Thus
I am capable of taking pictures of fast moving objects like flash lights.
On the other hand I have access to an
HTC One smartphone
with Android. The burst
mode feature there is particularly crappy. It shoots between 20 to 50 photos
(haven’t counted how much exactly), then takes a second to flash everything to disk,
then pops a question asking the user to select the best one and possibly delete
the rest. If you don’t want all of this just tap the back button to return to
shooting mode.
BlackBerry Hub
Hub is another well designed application which integrates all of your accounts and
messaging into the core of the OS although other mobile OSes have a similar feature
as well if I’m not mistaken. I just mention it because it is easy and comfortable to use.
BlackBerry Memory Management
BlackBerry 10 OS memory management is particularly crappy with respect to
the end user. I’m not sure whether this is due to QNX being real-time OS
or just the Java stack keeping stuff in memory.
After some usage my development Z10 will begin experiencing out of memory issues
(it has 1 GB of RAM vs. 2 GB in production hardware). This will lead to apps
crashing, web pages that were able to open, not being able to load and the most
annoying of all - camera starts taking pictures with random color spots.
After restarting the device everything is back to normal :(.
BlackBerry Date and Time Synchronization
This one I also hate a lot. It appears that the software is designed to
automatically synchronize over the Internet and without a reliable connection fails miserably.
After reboot (or even worse battery removal) the device will start with a fixed date and time
somewhere in the past. If it fails to synchronize or takes too long several things happen:
The Blackberry Hub application loads first (email and other accounts) which causes all sorts
of warnings of invalid SSL certificates. Which in their own right are annoying because Cancel
means dismiss the warning until the next connection retry; which blocks access to the main menu
for manual configuration;
All images taken by the Camera app will be saved on disk with the wrong date which makes you think
they are gone; I’ve found this by accident while scrolling way back in my history looking for something
unrelated.
Multiple File Selection
I haven’t tested this explicitly on Android or other mobile devices but on BlackBerry
the user needs to tap each individual object to select it. My guess is this is similar
on all devices utilizing a touch screen. However such interface makes it damn hard to
select a thousand files for deletion (the unusable results from the camera burst mode feature).
Luckily Z10 (and possibly others) has a shell application with cp, mv and rm -f commands.
Recently I’ve purchased a
wireless range extender
as the one shown here. It had troubles connecting to the upstream Wi-Fi router
because it used MAC filtering instead of password security. Luckily there was
a forum thread which helped
me figure it out.
DAP 1320 uses two MAC addresses
Everything was working just fine with MAC filtering disabled on the upstream
router but failed miserably when enabled. I thought the MAC address provided
on the DAP 1320 packaging was wrong.
It turned out the device had 2 addresses.
The one on the packaging is 70:62:B8:07:0B:76 and it didn’t matter if that
is enabled or disabled in the router settings. The second MAC is used when
trying to forward connections through the router. Both addresses differ by the
second symbol with a difference of 2. So I’ve enabled 72:62:B8:07:0B:76
in the router settings and everything worked like a charm.
Other findings
Unfortunately if a device is connected to the wifi extender’s network it will
bypass the MAC filtering employed on the upstream wifi router. As much as I dislike
using passwords for Wi-Fi I had to configure one for the extended network.
I’ve also found that when you save the configuration file from the device on your
hard drive it comes in a base64-encoded-line-by-line format. Pretty awkward.
Another pleasant (but not entirely surprising) finding was that D-Link included
a written acknowledgment of using open source components and an offer to provide
source code upon request.
The organization was good from the very beginning till the end.
The surprise came from the participants. There were more than 30 teams and this is a huge number! More info here - http://hackfmi.com/hackfmi3-winners/
Who was in the team and what we did
This time the team consisted of 2 Android and 2 Web developers. We also had a designer to make the project look nice.
For the first time we had an idea of what to do before the start of the hackathon and we also kept the tradition in team's name.
This year team's name was Eight (the previous times we were Six and Seven).
The topic of the hackathon was Hack for charity. We spent over a night to think on what we should do to encourage charity.
We wanted to make something that can be useful even after hackathon's end. Because often the projects that are done within these 2 days just do not get finished.
We also wanted to do something that really helps. We can make websites, collect clothes and so on but it is a lot of additional effort to manage these. The project had to just work.
Our project is called SMS Help. It is a mobile application (+ website) - SMS campaigns aggregator. Donating by sending a SMS is the fastest and easiest way possible.
What we did is a website with crawler which gets the info from Bulgarian's SMS campaigns website DMS (http://dmsbg.com/), the script automatically inserts, updates and deletes the records saving them into a database. We also added the other SMS campaigns - those from Unicef (http://unicef.bg/), Red Cross (http://www.redcross.bg/) and http://bgkoleda.bg/. The script runs once a day. The Android application connects with the API, gets all campaigns' changes and updates its own database.
Pretty simple but super easy to run and manage.
We won
A first place award. Trophy, diploma and money award, special award from Komfo.
Tomorrow we will release v2.0 of the Android application and within 2 weeks - maybe v1.0 of the iOS application.
May is not the most exciting month in terms of Eclipse development - it's all about final touches, release procedures and handing these bits to the users. With the previous said it might actually be the most exciting from users point of view. The team spent a lot of time on getting things from Luna release train built and available in Fedora Rawhide (future Fedora 21 release) - Platform, CDT, Linux Tools, Mylyn and their dependencies are available to Rawhide users now.
Yesterday I’ve visited an event organized by the
Atlantic Club of Bulgaria which
officially marked the launch of a digital national alliance in Bulgaria. This is
part of an initiative of the European Commission, called
Grand Coalition for Digital Jobs,
which aims to address the lack of
sufficient amount and quality professionals in Europe working in the
field of Information and Communication technologies.
The first part was few short keynotes, including one from deputy prime minister
and memorandum signing and group photo. In the keynotes (and afterwards)
the stress was on the lack of relevant ICT skills and the need of an estimated
1 million digital workers by 2020 in EU alone.
The next two sessions were panel discussions. The first one presenting the local
chapter of the Digital Coalition in Bulgaria.
The goals of the coalition are to:
help more people master more digital skills (not only as developers but also
proper usage of social media, how to create content, etc)
enable more people to choose digital jobs
help local talents present themselves on the global scene
How it (is supposed to) works:
initiate own ideas and propose them for implementation (to the ICT industry and broad public I guess)
stimulate learning through doing, learning by example using real use cases
help (and possibly sponsor) outside projects and ideas
Then the various companies supporting the coalition pledged how they are going to
help. The most interesting news from this panel was the announcement of a new HP
data center in Sofia which will be used as a training lab with access available to
students.
The second panel was about education and how to bridge the gap! The interesting points were:
Ministry of Education and Science admits they have finally realized that our educational
system and programs are behind current tendencies and need concrete steps in order to boost
education and science research;
Samsung will open their innovation lab at Sofia University to outside students as well;
We need to pay more attention to content and training of teachers because they also have
a skills gap while young children do not;
I particularly liked what Prof. Petar Kenderov from the Institute of Mathematics and Informatics
at Bulgarian Academy of Sciences said - in the outside world children are constantly sharing
and communicating with each other while at school (also to some extent in universities) they
are expected to not communicate, not share and keep quiet. He emphasized the value of learning through
experimentation vs. learning through reading and writing, e.g. the current way things work
and the old way of teaching.
Another thing that was obvious was that otherwise competing companies (e.g. Microsoft, Oracle, SAP,
VMware) were working together to fix some of the problems mentioned. However I’m a bit skeptical
that large multi-national companies will be flexible enough to make a positive change.
I’d bet on the independent organizations like HackBulgaria and
Svetlin Nakov’s Software University or initiatives by local Bulgarian companies
like the already proven Telerik Academy.
Here’s the entire program of the event, for anyone interested:
“EVOLVE DIGITAL” 10th June 2014 (Tuesday)
10:00 – 10:10 Opening: Gergana Passy, Digital Champion Bulgaria
10:10 – 10:20 Daniela Bobeva, Deputy Prime-Minister of the Republic of Bulgaria 10:20 – 10:30 Constantijn van Oranje, Head of Cabinet of Vice-President of EC Neelie Kroes 10:30 – 10:40 Jonathan Murray, Director, Digital Europe Special guest: Sandi Češko, Founder & President, Studio Moderna
10:40 – 10:50 Memorandum Signing and Group Photo 10:50 – 11:00 Pause
Rennie Popcheva, CEO, Digital Coalition Bulgaria Boyko Iaramov, Co-founder & Chief Process Officer, Telerik Marta Poslad, Senior Policy Advisor, CEE Google Petar Ivanov, General Manager, Microsoft Bulgaria Iravan Hira, General Manager, Hewlett-Packard Bulgaria Atanas Dobrev, CEO, VIVACOM Danny Gooris, Senior Manager, Oracle Academy Dimitar Dimitrov, Relationship Business Development, Lenovo Stamen Kochkov, Vice-president, SAP Labs Bulgaria, Chairman of BASSCOM
12:15 – 12:30 Coffee Break
12:30 – 13:45 Education in the Digital Era Moderator: Boyan Benev, Founder, Forward.li
Ivan Krastev, Deputy Minister, Ministry of Education and Science, Republic of Bulgaria George Stoytchev, Executive Director, Open Society Institute Sofia Sabina Stirb, Public Affairs & Corporate Citizenship Manager, Samsung Prof. Petar Kenderov, Institute of Mathematics and Informatics, Bulgarian Academy of Sciences Dr. George Sharkov, Director, European Software Institute - Center Eastern Europe Elena Marinova, President, Musala Soft, Chair of the Educational Commission, Bulgarian Association of Information Technologies Svetlin Nakov, Founder, Software University
13:45 – Lunch in Restaurant “At the Eagles” 11 Dyakon Ygnatiy str., in the building of Ministry of transport, 18th Floor
5-year old Seagate, 500GB. (In case anyone of you has ever thought of buying one.)
Luckily I had a 1TB 2.5' HDD that wanted to sell so I just came and replaced it.
But!
I had to install Windows 7, of course.
I have a Windows disk but it was burned about 3 years ago. However I put it in and got what? Error. "Windows cannot be installed on this disk. The selected disk is of the GPT partition style."
Problem. My laptop has no DVD drive.
Problem. My other laptop has DVD drive but there was no DVD at home...
Problems. I have a flash memory but it is just 1GB. My mother's flash is 2GB. I needed 4.
Problem. I can't use my external HDD because I had no place to put the information.
Problem. The other external HDD I already put into the PC.
Problem. The additional SPACE I had is my phone which is not a good idea.
I remembered there is a camera with memory card and luckily the card was 4GB and I also have a USB card reader (that I won about 10 years ago). Let the magic begin.
When I extracted the Windows to the memory card as a disk and put it in the PC - I got the same error. Luckily again I found this video https://www.youtube.com/watch?v=DQf9YqbD8WI showing what to do. In one sentense: When the "Install" button shows up, tap Shift+F10 to show the console and type "diskpart", after that type "select disk 0" (or "disk volume" to see all disks and then "select disk [the number of your preferred disk volume]"). Minimize the console. Simple as that. Hit "Install" and continue as every other normal flow.
Everything was good. I formatted the memory card once again, put the old pictures back and decided just to check if it still works with the camera. No. It didn't.
Format in different types, block sizes, full format and so on did not lead to any result. According to the Internet the memory card has never been working, I had to change it and the camera should be repaired for $100. Now I laugh but just several minutes ago...
The solution for the memory card was to put it in my laptop and use the same diskpart tool: "diskpart", "list volume", "select volume [the number of the memory card from the list volume step]", "active". And it worked.
Last week ended up with Bulgaria Web Summit.
The event was very big this year, with 4 halls and 600 visitors.
I was moderating the so called JavaScript hall and will concentrate on
what happened there.
This is what my hall looked like at around 10:00 and stayed pretty much the same
during the entire day.
Speakers at hall Rhodopi were (in order of appearance)
Delian Delchev talking about the JavaScript
revolution taking over the world and how this language has become the most
widely used programming language in the world.
Haralan Dobrev with some tips about development
workflows, git, continuous integration and unit testing.
Yoga for Geeks during the lunch break.
Boyan Dzhumakov with topics about home automation and Internet of things, who
demonstrated his bed side lamp controlled via a light sensor and Arduino.
Neven Boyanov continuing on the hardware topics with
comparison of ATmel, Arduino and Raspberry Pi and showing more examples of
small programmable devices.
Angel Todorov from Infragistics with a very
interesting talk about JavaScript instrumentation for performance analysis.
A very cool presentation and you should definitely check out his
cheetah.js framework.
Vasil Kolev with a talk about security
and web service design and how most of the web is doing it wrong :).
Unfortunately there is no video or audio recording available. If you find
some of the talks interesting and would like to get more info about it let
me know. I will ask the presenters to share their slides or give more details
where possible.
Don’t worry if you’ve missed the Web Summit in Sofia. There will be another one
in the autumn, held at Veliko Tarnovo. For more info please subscribe to the
newsletter.
Continuing to report on the last few events that took place in Sofia this week.
Day #2 of DigitalK started with the presentation of Piotr Jas of BlaBla Car.
What I really liked about it (picture TBA) was one particular graph depicting
the various types of travel (time before travel vs. cost of travel) and
visualizing different industries (e.g. air travel) or competitor companies.
The image clearly exhibited a blank space which is the exact market segment
where BlaBla Car have positioned themselves in.
A very practical and easy to use tool for entrepreneurs in my opinion.
From the rest of the keynotes I can outline two in particular:
Ivan Hernandez’ Disruptive Innovation and the future of Digital Transformation
and The future of Tech and Communities by Tim Röhrich.
I liked them because both were very inspirational although not telling you
something which you haven’t heard before. They were basically reinforcing
the spirit of the event.
In the small hall there was a workshop called
How to turn a good idea into a successful start-up led by Daniela Neumann,
which didn’t turn out to be what I expected. She was talking about the early
cycle of idea/customer validation and I don’t remember any particular example
being shown. Frankly most of the people have heard about this before (myself included)
and were quite bored. Not many of them stayed till the end.
The evening continued with the already traditional Silicon Drinkabout in Sofia
which hosted many of the conference attendees. I did a quick visit only
because I had to prepare myself for Bulgaria Web Summit on the next day!
The conference season (this week) is officially open! So here’s my report about it.
It started by accident last evening with a
warm-up event
sponsored by Twilio at betahaus Sofia. I had the pleasure to have a long chat
with Lisa from Twilio over a few beers.
Today was Day #1 of DigitalK which is the leading SEE
technology event. I’ve also visited the event last year and must say that this
time it is bigger. The main hall was totally packed. The WiFi connectivity has been
improved since last year but still sucked. I had more success using my 3G instead.
The most interesting part of Day #1 was the mini Seedcamp session which presented
10 startups. In order of appearance they are
Viblast, Stepsss and Talkie were the 3 finalists who also presented at the main hall.
Needless to say the coolest one from technology point of view is Viblast, which is
a peer-to-peer video streaming platform, utilizing WebRTC. They were also strong at the
presentation and look very strong at the business level as well. I wish them good luck.
Stepsss is essentially a shoe sole with sensors paired with smart-phone apps to
give runners more info and feedback. I like it because they are a hardware company
although there’s lots of competition in this space. I’d like to beta test their product
and see what happens when I go dancing all night long :).
Talkie is an educational app for children which helps them learn new languages. I had the
pleasure to see it in action before the actual presentation. The design is very cool
and the app does seem usable and complete. However I don’t see much of a technological
challenge here and I’m not sure how will they deal with the strong competition in the ed-tech
space. We’ll have to wait and see.
From the rest ScaleWhale and Smartoken do seem interesting but I really failed to get how things
will be organized on the technology side. Both ideas are run by a single person team, which
is a recipe for disaster (judging from my own experience).
Tomorrow is Day #2 of DigitalK and on Saturday I’m moderating one of the rooms at
Bulgaria Web Summit. Expect more reports soon.
This is one of the books that took me the longest time to read. It’s a hard
to read book because it is full of technical and scientific details, quotes
a great deal of facts and research and leads your mind into fields which
deserve a separate books for themselves.
The purely technical side of the book makes it a bit hard to follow as you need
to have a good deal of understanding of computing technology and concepts and
keep in mind what’s been said in previous chapters.
Ray Kurzweil starts with historical data about evolution and technological
progress. He postulates his theory of technology evolution called
“The Law of Accelerating Returns” and lists a great deal of examples to prove
that evolutionary processes are indeed not linear but exponential.
The next two chapters explain how much is the computational capacity of the
human brain, how to achieve that and how to reverse engineer the brain itself.
Think about 3-D molecular computing, quantum computing, brain imaging and scanning :)
Increased computing capacity and understanding of the human brain
(and general progress of science and technology in the mean time)
will lead to the three revolutions which will make the Singularity possible:
Genetics, Nanotechnology and Robotics (Strong AI). Ray gives a lot of
examples and current research which is well under way currently or
will become a reality in the next 10 to 30 years.
Following in the book is a list of impacts caused by the advancement of
technology and the Singularity itself. On the human body and brain, on
longevity, on warfare, on work and learning and play, on the Cosmos.
Because the Singularity is not a single event but rather many events which
happen in parallel and gradually over time we will have a hard time defining
what a human means. What is human, what is consciousness and where the line is
are questions which need to be taken into consideration. Ultimately the human
race will become (predominantly) non-biological.
How do you deal with dangers and shortcomings in technology? I myself as a QA
engineer have seen software fail in spectacular ways. How about machine failures?
Now how about nanobots in your blood stream or strong AI gone wild? Ray explains
some of the possible threats and proposals to overcome them. His point is
that benefits from advanced technology will be far greater than dangers and
we will be able to first design our defense systems before anything else that
may threaten our existence.
The last chapter contains examples of criticism and explanations why they
are incorrect which is the first of its kind I’ve seen in a book.
Epilogue
Human Centrality. A common view is that science has consistently been correcting our overly inflated view of our own significance. Stephen Jay Gould said, “The most important scientific revolutions all include, as their only common feature, the dethronement of human arrogance from one pedestal after another of previous convictions about our centrality in the cosmos.”
But it turns out that we are central, after all. Our ability to create models-virtual realities-in our brains, combined with our modest-looking thumbs, has been sufficient to usher in another form of evolution: technology. That development enabled the persistence of the accelerating pace that started with biological evolution. It will continue until the entire universe is at our fingertips.
It is published before UX for Lean Startups and is much more about principles than
any practical methods. Honestly I’m not sure if I took any real value out of it.
Maybe if I had read these two books in reverse order it would have been better.
The Hacienda - How Not to Run a Club
The Hacienda: How Not to Run a Club
by Peter Hook is one of my favorites. It covers a great deal of music and clubland history,
depicts crazy parties and describes the adventure of owning one of the most
popular nightclubs in the world. All of that while struggling to make a buck and
pouring countless pounds into a black hole.
The irony is The Hacienda became a legendary place only after it had closed down
and later on being demolished.
A must read for anyone who is considering business in the entertainment industry
or wants to read a piece of history. My favorite quote of the book:
Years after, Tony Wilson found himself sitting opposite Madonna at dinner.
‘I eventually plucked up the courage to look across the table to Madonna and ask, “Are you aware that the first place you appeared outside of New York was our club in Manchester?”
‘She gave me an ice-cold stare and said, “My memory seems to have wiped that.”’
Simple Science Experiments
Simple Science Experiments
by Hans Jürgen Press is a very old book listing 200 experiments which you can
do at home using household materials. It is great for teaching basic science
to children. The book is very popular and is available in many languages
and editions - just search for it.
I used to have this as a kid and was able to purchase the 1987 Bulgarian edition
at an antique bookstore in Varna two months ago.
Ronia, the Robber’s Daughter
Decided to experiment a little bit and found
Ronia, the Robber’s Daughter.
It’s a child’s book telling the story of two kids whose fathers are rival
robbers. The book is an easy read (2-3 hrs before bed time) with stories
of magic woods, dwarfs and scary creatures mixed with human emotions
and the good vs. bad theme.
Japanese Short Stories
I’ve managed to find a 1973 compilation of Japanese short stories
translated into Bulgarian. Also one of my favorite books.
If I’m not mistaken these are classic
Japanese authors, nothing modern or cutting edge. Most of the action happens
during the early 1900s as far as I can tell.
What impresses me most is the detailed description of nature and
surrounding details in all of the stories.
It’s a bit hard to read because the book is full of so many technical details
about genetics, nanotechnology, robotics and AI.
Ray depicts a bright future where humans will transcend our biological
limitations and essentially become pure intelligence. Definitely a good
read and I will tell you more about it when I finish it.
What have you been reading since January ? I’d love to see your book list
or connect on
Goodreads.
Difio is a Django based application that keeps track of packages and tells you when they change. Difio was created as closed software, then I decided to migrate it to open source ….
Do you remember I was going to
replace my laptop for a smartphone.
There’s the issue with a desk working environment and one solution is to buy an external
display. The other one is to use a
screen magnifier
as shown on the picture
(source eBay).
Does anyone have experience with these? Ultimately it should be possible to use
any 3x Fresnel lens magnifier and make your 5” phone display into a 15” laptop size one.
The magnifiers used for reading,
this one
are cheap and portable but don’t look very well around the edges.
If anyone has such a device at hand I’d love to see if this works for you or not.
Thanks!
Last week at HackFMI 3.0 one team had to display a form
which presented multiple choice selection for filtering, where the filter keys
are read from the database. They’ve solved the problem by simply building up the
HTML required inside the view. I was wondering if this can be done with forms.
The fourth HackFMI,
now traditional, hackathon was held this weekend.
It is over and I still can’t wrap my head around what happened during these 3 nights. Here’s
bits of code, beer, energy drinks and fun as I saw it.
A big thanks goes to Lilly and Misha who were running around like
robots managing the day-to-day activities.
Kudos to the rest of the team as well because they’ve established HackFMI as a tradition
and people already ask when is going to be the next event.
What
This year the topic was Hack for charity and immediate goal of raising money for
a sick kid. Most of the teams got to work to meet these goals. Only a few had worked
on slightly different charity (broadly defined) ideas.
My favorite two apps were Blago-darenie and SMShelp although they were not
developed with Django.
Blago-darenie is a simple WordPress
site listing donation campaigns. Instead of directly donating money one needs to
promise something (an action, an object, etc) and put a price tag on it. When the
promise is claimed the two parties donate the money to that particular campaign
and exchange the promised goods or services. I’ve promised to cook dinner
involving tasty meatballs from horse meat and serve one of my wine bottles to whoever
decides to donate 25 EUR. (disclaimer: I’m a good cook and love wine more than code).
SMShelp is an aggregator of donation campaigns via SMS
which are very popular in the country but lack a central repository for all of them.
A simple web site, live Android app and wonderful design secured the team the first place!
BTW Team 8 was Adrian and Vihren
who took part in all previous editions as well.
TODO
I’m glad both organizers and teams had listened to some of my feedback but there are
still things to improve. The most obvious one was that a quick communication channel
to all the teams is needed. Facebook and email just didn’t cut it.
I already have couple of quick ideas involving Django and Twilio’s cloud services.
Let me take a few more days to get it clear before going any further.
/me
I found myself mentoring as much as I could helping folks with Django or just
with general ideal or concepts, serving cake provided by Chaos Group
and opening stacks of energy drinks, going door to door and letting teams know deployment and presentation
details for the last day.
What surprised me a bit was that there were many new teams (some involving previous contestants)
who were very diverse in their technological background. This presented a challenge to
some of them as they had to use a technology which nobody on the team knew very well
and had to make a working app with that. One team even changed from Python to PHP in the
middle of day 2.
On Sunday I was pretty much helping the HackFMI team with whatever I can,
checking on my favorite teams from time to time and giving access to cloud servers
left and right to people who needed them.
Unfortunately I missed the Grand Finale due to unexpected hardware problems involving
big iron and 150 litters of loose water :(. See you next time!
We’ve heard about companies opening up their proprietary software products,
this is hardly news nowadays. But have you wondered what it is like to migrate
production software from closed to open source? I would like to share my own
experience about going open source as seen from behind the keyboard.
Difio was recently open sourced and the steps to go through
were:
Simplify - remove everything that can be deleted
Create self contained modules aka re-organize the file structure
Separate internal from external modules
Refactor the existing code
Select license and update copyright
Update 3rd party dependencies to latest versions and add requirements.txt
Add README and verbose settings example
Split difio/ into its own git repository
Test stand alone deployments on fresh environment
Announce
Do you want to know more? Use the comments and tell me what exactly!
I’m writing a longer version of this article so stay tuned!
Make a plan for each day/hour what you and the team are going to do. For example when are you going to write code, when are you going to eat, sleep, talk to mentors and so on.
Now having the plan make a list of what you are going to need and use - mostly software and any additional stuff.
Install all the software onto your computer and help the others do the same. Test everything and make sure it works for everybody.
In my case the team uses PHP with MySQL, Netbeans IDE. We also use git, CodeIgniter and jQuery. The steps are shown below.
Steps
Install xampp with PHP and MySQL, make a simple php page and test it.
Check the DB connection.
Install and set up git for everybody. Make sure everybody knows how to pull and push code and has access. Test. Install NetBeans.
One of the team should add and configure CodeIgniter and push it to the git server. The same with jQuery. Everyone should pull afterwards.
Note that everything should be tested.
Things to watch out for
Don't use remote database. We tried - when the Internet goes down we go down, too. Not a good idea.
Use a separate Internet connection (usb cookie dongle) or mobile Internet.
Mandatory: Bring a router if you have one, headphones, charger, coupler. :)
Optional: Lan cables, cooling pad, mouse pad, batteries.
Advices
Use simple and fast (for programming) technologies. PHP, JavaScript and Python are a very good choice.
Work in your most productive time the most. If this is 00-05h - OK.
Here's a way of having a good-looking simple Node.js API without having to search for what you need a long time.
The beginning
I use express.js. And here's how to start:
var express = require('express'),
app = express(),
port = 5555;
// listen to this specific port
app.listen(port);
// for the post requests we need to parse the data
app.use(require('connect').bodyParser());
Versions
Let's start with this one. All APIs have versions. Some just add functionality, but others change over time.
I need to catch requests. It's best to match a group of requests. Express provides methods for catching only get requests, only post requests... or all at once. It's best here to catch all requests and later execute what I need.
// match /v1 calls; skip potential problems
app.all(/^\/v1(\/|$)/, api_requests);
This one would match /v1 and /v1/something but not /v123. Which is what I want.
I say when a /v1 request comes - execute api_requests.
I also need to load the version for this API.
versions['1'] = require('./versions/version1');
Here's the place to say I have additional files to transform the url, filter it, get the API version and so on.
var api_requests = function(req, res){
var request_url = req.url,
url = helper.get_url(request_url),
version = helper.get_version(request_url),
endpoint = helper.get_endpoint(request_url),
method = helper.get_method(req);
versions[version].init({
loader: require('./loader'),
db: require('./db').init(),
print: res
});
try{
// ex: versions[1][comments][get].apply(null, [comments, all])
versions[version][endpoint][method].apply(null, url);
}catch(ex){ // catch the ex hohoh
console.log('invalid request', req.url, req.headers, req.connection.remoteAddress);
res.json([]);
}
};
So by doing this whatever request comes the API would execute the function named like the endpoint we are requesting.
Loader
I have a loader file which loads the methods and modules I'll use:
/**
* It's important to provide context for the functions here!
*/
var e = {
load_modules: function(modules, config){
for(var i in modules){
var module = modules[i];
this[module] = require('./versions/modules/' + module).init(config);
}
},
load_methods: function(module, methods, config){
for(var i in methods){
var method = methods[i];
this[method] = require('./versions/modules/' + module + '/' + method).init(config)[method];
}
}
};
module.exports = e;
Loading all modules
Loading all modules that I want to use for this API version. This is the version1 file.
/**
* Here we load all modules that are allowed to be used.
* The load_modules in the context of this object will
* make keys on this for each module whose value will be the module itself =
* object with keys the rest methods.
*/
var e = {
init: function(config){
var modules = ['comments'];
config.loader.load_modules.apply(e, [modules, config]);
}
};
module.exports = e;
Loading all methods
In order to achieve this when calling the init method of the versions[version] here's what happenes:
/**
* This module loads its methods using loader's load_methods in the context of
* this object here.
* The load_modules will make keys on this object with the
* supported methods whose value will be the method itself.
*/
var e = {
init: function(config){
var module = config.common.get_filename(__filename),
methods = ['get'];
config.loader.load_methods.apply(e, [module, methods, config]);
return e;
}
};
module.exports = e;
It loads the methods from methods and sets them as keys here. After this operation I'll have keys init and get on this module.
And when called get, the get method will execute itself.
The get is loaded from /versions/modules/get which means that modules are version-indipendent or at least in my case. In my case some modules are available in the newer API versions. In yours it may be better to be version-dependent which you can achieve easily.
Methods
/**
* A file that consists of the 'get' method and others that 'get' calls whenever
* it needs them.
* All the other rest methods are in different files.
*/
var db,
print;
var e = {
init: function(config){
db = config.db;
print = config.print;
return e;
},
get: function(){
db.query("SELECT * FROM comments;", function(err, data){
print.json(data);
});
}
};
module.exports = e;
That's the way a get method file looks like. It has get and other functions if it needs to call for a reason. It receives a config file with the db connection and printing function.
That's it
You'll say what's simple there? The simple part is that to add something new you only need to add it as an allowed rest method and write the code in the file.
All programming languages have one or two code conventions that are followed by all programmers using the language. But not PHP.
PHP has a lot of conventions so no developer follows any of them and writes the code as he wants. Also PHP has a lot of frameworks and every one of them has its own code convention.
So the problem is: How to choose a code convention?
And there are 2 ways: Use an existing one or follow your own.
It's nice to follow your own but best to use existing.
My decision on how to choose one was to put on a list the main topics and try to explain for myself why I should use this or that. After having answers on these main questions I chose an existing code convention which matches my preferences and adds all the little stuff that there's no need to explain. The important word here is "explain". Because no existing convention says "why".
I've made these conclusions after about 10 years of coding, the last 5 of which - almost every day. If you don't like them - you are free to make your own. :)
Tabs vs spaces
If you haven't gone through this discussion you should know that this is the greatest programming question ever.
I say you should use tabs and most importantly here's why:
Customizable - When working in a team some of the people prefer 4 spaces indentation, others - 2. If using tabs for indentation everyone can set the tab representation as he wants. Also when you have to check the code you have written years ago and your style has changed - you can customize it easy.
Tab is made for indentation and therefore should be used for indentation.
Using tabs instead of spaces you reduce the file size by 15%. Not believing - try it.
Curly braces placement
Curly braces should always be put on a separate line all by themselves. Always.
The reason behind this is that PHP is character-rich language - you can use all types of braces, all symbols you can write with the shift key and so on and so on. So if you put the opening braces on the same line and then start the body on the next line sometimes it becomes hard to read and understand what is going on. By putting the opening braces on the next line alone the body's scope is perfectly clear.
And all these braces should be used this way because this is the same character and there's absolutely no sense in writing it differently.
TRUE, FALSE and NULL
Should be written uppercase.
The difference between the constants that should be written uppercase and these three is minimal. Also these are all used to compare with variables ($something), constants (CHRISTMAS), numbers (105) that start with capital character.
Others
Files line ending: LF.
?> Close tag: Always missing.
So
I came up to comparing several of the famous existing code conventions and the conventions that the most famous frameworks use. The ones I compared were:
Zend
PEAR
PSR
Laravel
Phalcon
Symfony
CodeIgniter
Yii
CakePHP
Kohana
FuelPHP
WordPress
Drupal
Joomla
PrestaShop
Let's compare the three topics that I wrote about early. For the braces let's get the control statements braces.
Name: Tabs/Spaces - Same/Next - Lower/Upper
The correct answers should be: Tabs - Next - Upper
Zend: 4 spaces - Same - Lower
PEAR: 4 spaces - Same - Lower
PSR: 4 spaces - Same - Lower
Laravel: Tabs - Next - Lower
Phalcon: 4 spaces - Same - Lower
Symfony: 4 spaces - Same - Lower
CodeIgniter: Tabs - Next - Upper
Yii: Tabs - Next - Lower
CakePHP: Tabs - Next - Lower
Kohana: Tabs - Next - Upper
FuelPHP: Tabs - Next - Lower
WordPress: Tabs - Same - Lower
Drupal: 2 spaces - Same - Upper
Joomla: 4 spaces - Same - Lower
PrestaShop: Tabs - Next - Lower
So what we see here is that the old ones follow the PSR while the new ones use tabs for indenting and put the braces on the next line.
So I have to choose CodeIgniter or Kohana. After looking through the full conventions of these two frameworks I chose CodeIgniter's.
If you wonder what convention you should use - take a look at the code you've written through your career. If you understand everything fast - that's a good sign. If it is a lot of effort to you - that's bad.
So whatever you choose - make sure you won't swear when you have to read it several years later.
Isn't it sad when you go somewhere, you are waiting for something or whatever and you need to open up a website or use the Internet for some reason.
You don't have mobile Internet or it's 64kbps which for me is not "I have Internet".
If you want to get something you have to give something
..people said. And they are right.
If you have ever wanted to use the Internet and there have been a lot of password-protected networks and none free - think for a second. Is your home network free? If someone is into your shoes and sees your network as a protected one?
If you want to make the world a better place start with yourself so open your router's admin panel and setup a free network.
In my TP-Link WDR3500 it's called Guest network. What I did is to:
Limit the Egress and Ingress bandwidths to 1024kbps
Start it as a 2.4GHz network named "Vireless free"
Disable wireless security
Access time set to 24h everyday
Save
Even if I help just one person I would be happy because somebody else (or the same person?) has helped me when I had the need.
For me 1mbps is not a big deal but for someone it might be. :)
Today I ran into need to have Internet on my mobile phone through the PC no matter why.
The usual approach
I tried the usual approach - to set-up a wireless ad-hoc network from my Windows PC and then connect to it from the Android. It seems that the Android can't see the network so I can't connect to it.
On the Internet it's written a lot about downloading applications and programs but I wanted to do it with the programs I currently have.
Now go to Control Panel \ Network and Internet \ Network Connections.Choose the active Internet connection that you have. Right click on it, Properties, Sharing, check Allow other network users to connect through this computer's Internet connection and choose the connection name of the new network that you just set up, then click OK.
Turn on the wireless onto the mobile phone and connect to this network.
Many people complain about how the Eclipse platform is not helping building a community but there are some other thoughts that I can't get rid of.
People want to drive "big" changes from the beginning but in reality it doesn't work that way in no FOSS project - one has to start with small things, not so small, slightly bigger, big, bigger, huge, etc. People that are dedicated go through the process and gain the ability to change so much for the reason that there is not that many other people working on the platform.
Is this perfect - NO, not at all. How can it change? There is only a single way I see - more people start contributing - but not contributing the next big thing - help us revive the platform. Things like:
improve test suite - no big change can happen if the committer is not at least partly sure that nothing bad happens. That's a huge opportunity for people wanting to join as it doesn't require that much deep knowledge from the beginning. E.g. in SWT it was a test infrastructure work (~100 commits) just to modernize to the state where there is one test suite for all platforms with all the quirks in it to make it possible to run from maven build in a sane way. And tests can be run from the maven build run but still fail!!!
bug triaging - Yes, having 1142(at the time of writing) open bugs for SWT/GTK only is not helping me see new problems. Verifying bugs, producing snippets that make it easier to reproduce, patches that fix it or simply closing the bug cause it has been fixed long ago. This is really valuable help as it is huge time drain. Reports that are vague or too big don't get that much attention as the current amount of people is already having problems driving the next release!!!
cleanup the codebase - Making use of new features available for years, standardizing on given idioms, removing deprecated. All these boring things that make it easier to not be afraid of change, to jump into the project easily, to verify things easily, etc.
improve the build system - Huge task and huge time drain for potential contributors. If the build takes so much longer than needed even without running the tests in it, how can someone easily verify a change. Yes, I mean building the whole platform and running all tests to verify that you're not breaking something few layers above you.
If/when we get the things above done - jumping into the problem space would be way easier and there would be enough people with experience in it already so we don't get to this state again.
With so many Eclipse users and people unhappy with the current state of affairs maybe it's time to try different approach. Is this the right one? No idea. Will it work? No idea either, but there is only one way to know it - let's try.
This is plea to the people that haven't been involved into Eclipse and wondered whether they can help improve - Yes, you can.
P.S. These are my own thoughts and doesn't represent a statement from any of the Eclipse groups I'm member of.
Let's start with this: I'm not so Linux-familiar and when I run into problems I search in Google.
That's what happened the last night.
I decided to install mysql onto my VPS. I checked that I should just run
sudo apt-get install mysql-server
Wrong!
What went wrong
Of course I tried several times to install whis with no effect. I started searching the Internet for information why it gives me
dpkg: error processing mysql-server (--configure)
All the information didn't help me. I tried everything that I found so I updated my system and whatever you can think of. No luck.
The system runs Ubuntu 12.10 x64 from DigitalOcean.
I tried purging, cleaning, autoremove, autoclean, update, upgrade, configure... So it became clear that I should do something different and with another mysql version because with the default - 5.5 - is not going to happen.
The solution
1.First download the .deb package from http://downloads.mysql.com/archives/community/. Select Debian Linux and whichever version you want, then download it. The mysql website is so messy that I lost a couple of minutes to find where this download section is.
2.If you have already tried installing be sure you have removed the mysql-server, directories and then cleaned.
Since I started participating in interviews for junior developers in the company I'm currently working for I started thinking of logical questions to ask the candidates.
That's the way the "clock questions" came out and I'll share two of them with you now.
1. What's the angle questions
What's the angle between clock's hands when the time is [HH:MM]. For example:
What's the angle between clock's hands when the time is 11:50?
2. How many times questions
How many times do the hands of a clock [action] [period]. For example:
How many times do the hands of a clock overlap within a day?
I've been using Chrome since it came out about 5 years ago.
I've always loved it but the truth is that there are Chrome alternatives that are pretty better than the Chrome itself. Also, Chrome started becoming slower and heavier that ruins the UX, especially if you are a web developer.
The Chrome Canary is the developer version of Chrome. Using Canary you're always 1 or 2 versions ahead from the official Chrome. You know what will be available in the next Chrome and you are one of the early adopters. Cool. The bad thing is that these versions have bugs and sometimes these bugs are pretty massive. I've reported more than 10 very serious bugs that have prevented me from using the browser properly.
Chromium is an open-source project supported mainly by Google. Chromium is the basic stable Chrome that won't run your PC out of memory. Chromium has all the features that Chrome has - including accounting, dev tools, extensions and so on. Chromium is faster and lighter but using it you may not be updated for a couple of months.
On my home PC I'm with the Canary while on my work PC I use Chromium. And I'm happy with that.
I know there are a lot of Chromium-based browsers but Google is Google. :)
I've used socket.io in several personal projects. I like it because once you manage to make it work, the next time it's just 15 minutes with the whole installation process and everything.
It solves the problems related to the realtime delivery of messages and does it well.
But as everything else does it has some problems. One of them is that it's not working properly on Safari for Windows and some other specific combinations of Browser [version] + OS.
Going away from what is said on the project's home page - that it is with full fallback support and so on. After a week of investigating what the problem is I finally found that the WebSockets actually have 2 implementations.
The first is uni-directionaland is still present in some browsers while the second is bi-directional.
In the first, sending data from A to B and backwards has to be done using two different connections.
So the socket.io supports websockets but it needs the bi-directional version.
According to this article (and not only) http://stackoverflow.com/questions/17849517/check-to-see-if-websocket-is-hixie-client-sidethere are browsers that support only the first one. So when the socket.io asks them if they support WebSockets they say "Yes." after which they are able to only receive or emit events but not both.
Luckily when requesting to connect to the server we can tell it in what way we want to communicate by passing an array of prioritized connection mechanisms.
So we can say: var sio = io.connect(url, {transports: ['websocket', 'xhr-polling']}); and we are going to connect using WebSocket first and if it fails - with XHR-Polling.
It seems natural to us that if the browser uses uni-directional WebSocket socket.io will fallbacks to the XHR-Polling. But it doesn't.
So we need to fix it manually and here is how.
var transports = {};
if("WebSocket" in window && WebSocket.CLOSED > 2) { // if modern browser
transports = {transports: ['websocket', 'xhr-polling']};
}else{ // else fallback
transports = {transports: ['xhr-polling']};
}
var sio = io.connect(url, transports);
This code fragment checks whether the browser supports WebSocket and if yes - if the CLOSED state is greated than 2 (the old CLOSED state was 2, the new is 3 currently).
And only if these two conditions are satisfied - WebSockets are used.
Here's a great table http://caniuse.com/#feat=websockets showing where we are able to use the bi-directional WebSocket connection and respectively - where we should fallback to the uni-directional.
Although I'm using PHP and JavaScript in my everyday work I also check the news and what's happening in the world. I try to predict for myself what's the trend for programming languages' use and applications.
So, that's my list of the top 3 languages that you should take a look on in 2014.
#1 SQL
SQL (Structured Query Language) is a special-purpose programming language designed for managing data held in a relational database management system. Originally based upon relational algebra and tuple relational calculus, SQL consists of a data definition language and a data manipulation language. Although SQL is often described as, and to a great extent is, a declarative language (4GL), it also includes procedural elements.
SQL is a mandatory requirement for job offers, your personal future development and thinking capabilities; for structured data storing.
#2 Java Android
Android is an operating system based on the Linux kernel, and designed primarily for touchscreen mobile devices such as smartphones and tablet computers.
Android is open source and Google releases the source code under the Apache License. Android has a large community of developers writing applications that extend the functionality of devices, written primarily in the Java programming language.
Android is the world's most widely used smartphone platform. Despite being primarily designed for phones and tablets, it also has been used in televisions, games consoles, digital cameras and other electronics.
As of November 2013, Android's share of the global smartphone market, led by Samsung products, has reached 81%.
Android is being used in all kinds of electronics and where it's not - it will be. If you want to be up to the technology and programming world - better start learning it.
#3 Objective-C
Objective-C is a general-purpose, object-oriented programming language that adds Smalltalk-style messaging to the C programming language. It is the main programming language used by Apple for the OS X and iOS operating systems and their respective APIs, Cocoa and Cocoa Touch.
Having Objective-C just for controlling Apple's platforms is not enough for the language to survive. So Apple started porting it to other electronics just like Google did with their Android. I expect to see Objective-C programs controlling some costly electronics soon.
Whichever of these you choose I think you won't be wrong.
Since I love JavaScript a lot, it happens quite often to have the need to convert String to Number.
And because whichever function I use I always have problems here's a comparison between several converting options and which one is the best.
In order to get the best results I'll try to convert to Float instead of Int.
Test cases and expected results:
123.4 --- 123.4
"123.4" --- 123.4
"0123.4" --- 123.4
"123.4x5" --- 123.4
"123.4.5" --- 123.4
"" --- 0
"-0" --- 0
"0.0" --- 0.0
"-123.4x" --- -123.4
"1.2-3.4" --- 1.2
NaN --- 0
"10px" --- 10
null --- 0
"test" --- 0
0x10 --- 16
undefined --- 0
{} --- 0
[] --- 0
[{}] --- 0
"undefined" --- 0
And a list of the different ways to convert to Number that I know or managed to find.
No way to get the right results with all these functions?
Taking a look into the detailed results and with several more console.logs and tests I finally managed to get the right way for converting String to Number.
And the solution is:
parseFloat(x) || 0
parseFloat(x) || 0 passed all the tests and seems to be the perfect solution so far.
Thank you, JavaScript, for making my life interesting! :)
Today Perl helped me again to solve a boring office problem. The colleagues gave me a presentation with almost 1000 slides. It was designed for a theatre subtitles. The slides was simple. Just a sentence per each slide. Only the colors was mistaken. Not black on white but white on black. My colleagues spent hours in googling for M$ Office bulk color change function. Then something blinked in me. It was Perl’s Regex {}.
The new open Office formats – ODF and OOXML are both zipped XML files, binary media content and files with metadata. I converted the presentation to odt (It was on the old crappy ppt) and then, just
The interesting file for me was content.xml. It’s a verry big XML text file, so it’s hard to be read both by a human and a text editor, but Sublime Text withstand. Because the slides were very simple, there was only one text style. So, here is the interesting stanza:
The initial team (Vihren, Radost, Rosen) made a presentation (in bulgarian) on how to e-market such an application that we presented on one of our lectures.
Some of my Facebook friends have enough free time to tepost stupid Facebook page images, Tumblr gifs and other crap. Others are just not clever enough. The worst is when there’s a new reality show on the TV, a new internet meme or “just-share-crap” trend. I don’t wanna be part of that. F.B. Purity helps me to filter the Facebook wall with more advanced tools than the standart FB options. It supports custom words blacklist. Mine is shared on GitHub. :)
It’s time to convert the physical disk to a virtual image. I’m using KVM almost everywhere, so, this tutorial will be about KVM. You can use the images in Xen/VMWare almost the same way.
First, install the VirtIO drivers for a better performance. The Fedora team builds isos with binary executables. Check the KVM documentation for the newest info.
First, attache a new VirtIO disk image to the machine. You can use the previously generated image in the installation from Part 1 or create a new one. The size is not important. It’s needed just to recognize the new storage format in Windows.
When it’s installed, you can deattach and delete the temporary VirtIO disk.
And now, the converting. I use mostly three tools for this thing:
CloneZilla – Open Source Linuxdistribution for creating disk images
Byte copy with dd. I don’ recommend it because will copy all of the sectors of the disk, even the “empty” ones. The dd way is OK when you will use LVM for a storage format.
I will show you how to convert it with the VmWare tool because It’s the easiest way, I think.
You need a free space somewhere to put the converted image from the tool. It’s possible to mount a directory from the server, to mount a Samba share or if the physical disk is healthy and there’s enough free space, you can put the image right in C:.
Click on “Convert machine”
This local machine
VmWare Workstation or other VmWare virtual machine; choose a directory
Summary..
And the job is running
When it finnish, you will have a directory with the VMDK image in it. KVM supports VMDK, but it’s better to convert it to QCOWp2 with:
1
$ kvm-img convert -O qcow2 WinXP.vmdk WinXP.qcow2
Just put the QCOW2 image in KVM and your XP is virtual :)
There are still online many dirty legacy PCs which cannot be reinstalled. The most common problems are that they are installed with a special software and the CDs are lost or a license problems.
But what will happen when your zombie Durom 1300 dies? And your boss wants to use the accounting software ASAP.. The best scenario is when your HDD is healthy :)
First, you shoud find a cheap HDD –> USB converter. This is the clearest solution because I don’t want to turn off my virtual hypervisors and probably, the old machine would have an IDE HDDs. Chinese combined IDE/SATA –> USB converters can be found for 15-16$.
This is the one I’m using..
IMPORTANT!!! The old PC’s are too dirty and their cases are sharp and dangerous! You should have a DPT vaccine and suitable protective clothing!!!
The HDD must be put on a PC with a hardware acceleration and KVM installed. In my case, my personal laptop was the salvation. I prepared a dummy VM with virt-manager, just to generate the XML file for libvirt. Use the simplest configuration. WinXP runs on an old hardware… Here are some steps in images:
…
Just one CPU with 1024Mb Ram is OK
It’s not necessary to have WinXP iso. Use something just to generate the XML for LibVirt.
The disk is also not revelant. It will be removed after the configuration.
Better use i686
Force off the machine after this window and open the terminal.
In the terminal, type $virsh dumpxml WinXp > WinXp.xml . Open the generated text file with your text editor and find this stanzas:
/dev/sdX must be your hard drive, connected with the chinese gadget. Make sure it’s not mounted on the host system. Now your XP machine should run directly from the hard drive.
This year, on OpenFest 2013 I will talk about Ulteo OVD – Open Source Application Delivery system. The conference shedule was full and there was just a place on the Lighting Talks, but it’s enough. I will cover the core functionality and some words about the company which is developing Ulteo. It’s a good idea to invite the developers on the next OpenFest.
I have a working setup in the Francophone center of Sofia University, so it’s possible to show it as a demo from my laptop outside.
OpenFest is the biggest conference about Free and Open Source Software and “Open Mind” in Bulgaria. Each year international guests from big projects and companies are invited.
You can see the shedule and the address in the OpenFest site.
Just a small dummy C project from the highschool, made probably in 2008. It’s completely useless. I still keep it because someone can use it as an example of using an escape characters in Bash.
Zentyal, The Linux Small Business Server includes the most important services for a small or medium company. Most of the services are integrated around OpenLdap. Since version 3.1, Zentyal uses Samba4 as a Directory and File Sharing service.
I’m maintaining the computers in the Francophone center in University of Sofia. Everything in this place is with Ubuntu workstations.
There was a major hardware update this year. We got new servers, workstations and laptops.
Following the info from this forum topic, I installed Ubuntu 12.04 LTS for the desktops and Zentyal 3.2 as a Directory and file server. Home directories are on NFS share in Zentyal, so that the users can use their own profiles on any workstation.
First I decided to use Centrify DC Express (Documentation) as an Active Directory client Samba shares, like in the forum topic. This type of setup gave me the possibility to use Samba 4’s advanced directory options because CentrifyDC immitates M$ Windows client and the security of Samba. It seemed to work in the first test, but then bugs appeared. There are some privilege issues with Samba. For example, PulseAudio cannot initialize on boot because it cannot create the ~/.pulse directory. There were the simmilar issues with Firefox on some of the profiles.
Then I decided to use NFS with Centrify, but another issue appeared. Centrify makes UID and GID different than the ones in Zentyal and users cannot write to their own profiles. NFSv4 can solve this problem with remapping, but it’s still not documented and there’s a lack of information on internet. If you are interested in it, you can search for “/etc/idmapd.conf”.
So, I choosed the standard LDAP setup, like in the forum topic and NFS. Well, another bug appeared but it can be fixed with a small hack.
You must comment the “If” statement about gsettings (dconf) in /etc/X11/Xsession.d/90qt-a11y :
Before (/etc/X11/Xsession.d/90qt-a11y)
123456789101112
# -*- sh -*-# Xsession.d script to set the QT_ACCESSIBILITY env variable when accessibility# is enabled.## This file is sourced by Xsession(5), not executed.if[ -x "/usr/bin/gsettings"]; thena11y_enabled=$(gsettings get org.gnome.desktop.interface toolkit-accessibility)if["$a11y_enabled"="true"]; thenexport QT_ACCESSIBILITY=1
fifi
After (/etc/X11/Xsession.d/90qt-a11y)
123456789101112
# -*- sh -*-# Xsession.d script to set the QT_ACCESSIBILITY env variable when accessibility# is enabled.## This file is sourced by Xsession(5), not executed.#if [ -x "/usr/bin/gsettings" ]; then# a11y_enabled=$(gsettings get #org.gnome.desktop.interface toolkit-accessibility)# if [ "$a11y_enabled" = "true" ]; then# export QT_ACCESSIBILITY=1# fi#fi
According to the forum topic, you need to install these packages on the Ubuntu client to run LDAP:
1
$ sudo apt-get install install libnss-ldap libpam-ldap libpam-mount winbind smbclient cifs-utils ldap-utils #Ignore all requests, just hit Enter
And for NFS:
1
$ sudo apt-get install nfs-common libpam-mount
Then, create again the file /etc/ldap.conf :
123456789101112131415161718192021
base dc=neo,dc=lan
uri ldap://10.1.100.1:390
ldap_version 3
binddn cn=zentyalro,dc=neo,dc=lan
bindpw jw4xF8KRS@IsEqxCbt=0
scope sub
bind_policy soft
pam_password md5
nss_base_passwd ou=Users,dc=neo,dc=lan?one
nss_base_passwd ou=Computers,dc=neo,dc=lan?one
nss_base_shadow ou=Users,dc=neo,dc=lan?one
nss_base_group ou=Groups,dc=neo,dc=lan?one
nss_schema rfc2307bis
nss_map_attribute uniqueMember member
nss_reconnect_tries 2
nss_initgroups_ignoreusers avahi,avahi-autoipd,backup,bin,colord,daemon,games,gnats,hplip,irc,kernoops,libuuid,lightdm,list,lp,mail,man,messagebus,news,proxy,pulse,root,rtkit,saned,speech-dispatcher,sshd,sync,sys,syslog,usbmux,uucp,whoopsie,www-data
Remarks:
base – see “Users and Groups – LDAP settings – LDAP information – Base DN (in the Zentyal web frontend)
uri – use the IP address of your Zentyal box and Port 390 to reach Ldap
binddn – run grep ^binddn /etc/ldap.conf on your Zentyal server’s shell
bindpw – run grep ^bindpw /etc/ldap.conf on your Zentyal server’s shell
Create a link for the ldapsearch tool:
1
$ sudo ln -s /etc/ldap.conf /etc/ldap/ldap.conf
For NSS:
1
$ sudo auth-client-config -t nss -p lac_ldap
You can test the configuration with $id USERNAME where the username must be from the Active Directory.
To mount the home folder you need to insert this line in your /etc/security/pam_mount.conf between <!— Volume definitions —> tags:
It’s better to use TCP because sometimes transferring big files freezes.
Nolock disables file locking. According to the manpages, this option is deprecated and is required just for an older servers. I think it’s better to be used because sometimes Firefox locks it’s profile when the session freezes and the users cannot login from other machines.
rsize and wsize specifies the chunks of data that the client and server pass back and forth to each other.
This configuration works for me, but maybe the options= tag must be in <mntoptions> tag.
About the server
Zentyal is well documented. You can install and configure all the needed components in ~30 minutes. Just check Zentyal.org.
Additionaly, you need the configure the NFS server. These packages must be installed:
We all hear about the new and cool web IDEs - I looked at few of them and somehow all looked too poor for someone used to do pretty much in his IDE (that's why we have I-ntegrated in the name, right?). So I decided to take another look at the problem from different POV and here it is:
That's Anjuta running using GDK Broadway backend, sample C project created, compiled and launched(the empty window on the right) - all in the browser. Simple instructions that work on Fedora 19:
1st terminal - start broadwayd
2nd terminal - GDK_BACKEND=broadway anjuta
browser - http://localhost:8080
Isn't that cool?
As an Eclipse user and developer I wanted to immediately see my Eclipse working on my development machine and being able to use it from various connected devices at home for small things like - launch hudson build via mylyn builds, comment on bug via mylyn tasks, pull from Gerrit for a quick review and etc. all via plain old http while having my setup working and no vnc or alike solutions needed (that take more time to get on your phone than few web clicks). To be honest I didn't expected it to work but this doesn't mean I have to stop dreaming.
Broadway GDK backend is GTK 3.x feature so one first need to run eclipse on GTK 3. That's easy - `SWT_GTK3=1 eclipse` and you have it. But there is one more prerequisite to use different GDK backends - your app should not do direct X calls and here we fail - eclipse simply crashes because of the direct X calls done if one tries `GDK_BACKEND=broadway SWT_GTK3=1 eclipse`.
Allowing using different GDK backend is important for Eclipse (at least on Linux) as elliminating or changing X calls is needed to also make Eclipse run as native wayland client. The future will catch Eclipse sooner or later.
If you do want to see such future for Eclipse please test Eclipse on GTK 3.x, report bugs, help us fix the issues, provide patches and spread the word about such possibilities so more people can potentially join the fun. Also feel free to contact me directly for anything related and help my dream come true.
It's a nice start of the week to read this. As a Linux distro guy this makes me really happy as it's a first step in the right direction to fix some of the long standing problems for "source-first" developers. Java programs are full of references to libraries that have been cool and state of the art ~10 years ago but it's time to let them R.I.P.
Dropped support for old targets in javac will hopefully have the nice side effect to reducing the private patched jars many projects has in their scms. (Please stop including activation.jar with your app!)
Not to mention that it will help moving to newer JVMs - yes, I'm looking for the moment noone will ask me to compile my projects to target 1.5 as it would be just impossible. The answer would be awesome - javac don't support it anymore!
Sometimes I even wish to see something like "one plus FIVE back" for the JVM itself - aka Java 9 stop loading bytecode from pre-1.4 times. This would lead to huge cleanup in resources used by applications by making people look forward as now it's impossible to have a coherent support for even 2 application with the same set of libraries as each of them has stalled some dependency in the very distant past to the state it becomes impossible to collaborate. And NO, shipping private copies is not OK - search for the jakarta-httpclient CVEs which would not be fixed as it is EOLed and no further releases will happen(rightfully as it has been EOLed for years already!) but many applications expose their users by shipping a private copy most of the time not even knowing.
Even if this has been standing in my mind for quite some time I never expressed it in non-private conversation and reading that there is a hope made me start the week with some joy :).
Before reading further please watch "LibreOffice cleaning and re factoring a giant code base" from this year's FOSDEM conference. Note that reading this post without watching the video would put a lot of things out of context!
The one and single most obvious thing for me from the whole talk was "it's about the people". Watching it one will notice the amount of people that started contributing in there free time and how fast LibreOffice grows in number of contributors. As one that works almost entirely with Eclipse.org projects (especially Eclipse as an IDE) this made me ask a very basic question:
How did a pure end-user application managed to attract more developers to spend improving it in their free time than an IDE ?
I started to think about initial experience I had trying to improve various plugins and realized that we do fail entirely in welcoming new committers. Even after one has number of patches in, if one just opens a bug(gerrit review) and attaches his/her patch - nothing happens for months (even years!). Or the patch will comments why it can't happen now and nothing will happen for months/years again. Now I'll try to fight some of the most common myths used to explain the situation:
there is release pressing - this is seen for milestones, SR releases, etc. But there is always something pending and most of the time people start with so small contributions that they can hardly affect the whole release train. Potential contributors might be more happy if instead of saying it can't happen now and forget it, we do comment a week later once the M-build is out (this covers most of the calendar year) and work with the contributor to get his change in.
it gains us nothing - wrong! for at least two reasons: First: one of your users identified the need for it and cared to spend time to contribute it back, one could bet that he/she see it as important; Second: even if there will be no technical benefit immediately - that's one more contributor and this makes difference soon after that.
old versions depend on something that this patch changes - You know there is a reason for calling a version an old one. Don't hold the new development - we have the awesomeness of git - branching, cherry-picking and so on can hardly be easier. Old way of doing something belongs to maintenance branches. Here we come to catch 22 - there are not enough people to support two ways but we don't want new contributors too. New people need new things.
this part of the code is "tabu" - only blessed ones can touch it. Telling a potential contributor - "you're not smart enough" isn't it ? Well, I read it differently - if in my code there is something so sensible that I should be afraid is someone touches - it needs a fix (or ever rewrite?) as soon as possible so it can continue improving as normal part of the codebase. As long as someone starts spending his time on it of course.
it's not tested with other version of third party library - this is seen really often from my point so it's like a personal rant. If someone requests a dependency range to be bigger one can think that he tried it or that even a product using the version outside of the range is shipped. And this means nothing as the project can continue ship its preferred version but you can make the life of people depending on your code easier for no cost.
the contributor already ships a fork so he/she can continue do that - If one ships a fork and submits patches back it clearly means he doesn't want to do that but he is forced to do that because the project is not interested to grow in the area he needs.
If we want to grow as community members, everyone has to go through his projects bugzilla/gerrit see for pending patches or requests and make the easiest one come in the next release. Or we will soon get to the point where people will not even report bugs as they would not believe anyone will look at the bug opened and that would be a failure growing to disaster. Seeing even well respected people withing the community having to poke numbers of time for really simple patches to be applied makes me very sad as this is pure energy lost. One can fix few more bugs instead of rebasing patch 3 times and poking 5 times.
It's not too late for a change we need to just encourage people by accepting their changes or work with them till the change is in a good enough change. Just a bit more openness and trust to new contributors is needed. So do we actually want to grow the community?
If we keep the pace I might get used to blogging more often. A picture is worth a thousand words so here it is:
Not much to see but it's the first ever screenshot of SWT on GTK3. Not much more can be done for now and the label was supposed to be centered (source) but still we are finally at the stage where we can start showing things. Big thanks goes to Silenio who bite the bullet to disable/workaround things so we can start running the code instead of targetting perfection with the compiler.
That was amazing week - 29 compile errors were fixed! On the other side my metric is broken - I have been counting only errors in os.c while there are a bunch of others hiding in os_structs.c too. Anyway, at least for what we were counting there are 31 more errors left and they are a prerequisite for even trying to build os_structs so we continue working on them. So what was fixed last week: * 2 gdk_colormap_* functions are dynamic now as they are removed in Gtk 3 * 3 drawable/pixmap functions are no longer used in Gtk 3 codepaths * 14 errors - GdkRegion/cairo_region swap landed in * 9 gtk_style_get_*_gc are ignored - used only in the unfinished Theme api * gtk_widget_size_request - time will tell whether this was the correct call.
Additionally a number of other fixes for the structs landed too but I do not keep track of numbers there as I compile them in my blind_convert branch so the numbers are flawed by the dummy fixes done for unfinished things in os.c. And now the good news - one can successfully compile my branch in question and try to run an empty shell example - nothing will show but it would not crash either, which was the state for long time preventing me from making this branch public. Don't count to much on this branch - it's known to be broken and serves only as a test bed before things go into master.
Another week - 15 down! 60 more problems expect us before trying to run on top of GTK 3. The problems fixed this week are: * 5 gtk-paint* functions replaced by the new gtk-render* functions * GdkDragContext, GtkSelectionData and GtkTargetPair structs are no longer used directly but via accessor methods * GdkGCValues, GdkImage and GdkVisual structs sizeof is no longer needed * gtk_cell_renderer_get_size replaced by gtk_cell_renderer_get_preferred_size
SWT doesn't run on top of GTK 3 (latest and greatest ) but work is ongoing. Last week was a really productive one getting us to the state of less than a hundred compile errors (well, some are warnings actually). Not only that but we are down to 75 as of today. A number of others are pending reviews in bugzilla giving us hope that speed should not decrease.
Here is the list of all the GTK problems we have identified for now. Be fast and pick one (check the tracker bug first), open a bug and block the tracker so we know someone is working on the issue. There is still time to add your name to Thanks list. If you want to help out checkout swt from git and when building natives instead of the plain `sh ./build.sh` do `GTK_VERSION=3.0 sh ./build.sh` the list of errors is what's still pending. Nothing else but code counts as help for now! There should be semi-regular updates on the state from now on.
Big thanks to SWT project members for making me a committer to speed up the work and to my teammate Anatoly Spektor for his hard work on the topic in the last months.
Criticizing Gnome looks like the most popular sport this year in tech land so here are few reasons why many developers are probably jealous to Gnome developers or at least why I am.
Haven't you dreamed of having consistent codebase in your project? What about consistency through out most projects that come from the open source foundation hosting your project? I definitely wish this was the case in Eclipse.org land. Even if Gnome developers haven't achieved it everywhere they did it in many areas. Remember that even collecting and structuring the data is something that most other projects haven't tried to do!!!
Reason 2:Forward looking developers
No "if it ain't broke, don't fix it" mantra. The difference here is outstanding - even if the problem is damn hard Gnome developers work hard to get it fixed ASAP, in many Eclipse projects we wait for the problem to hit us hard and try fixing it at a time when it's way harder to do it thanks to many depending on the broken behaviour and the relevant no longer part of the community. Others (like the maven guys) take it to the other extreme - make stable releases depending on alpha software. If you want a proof - run mvn and watch for plexus-container-default 1.0 (alpha-8, alpha-9, alpha-9-stable-1!... alpha 30) coming your way. Many of the projects initiated to fix long standing problems have their hard first steps and left bad taste in some early adopters but most of them end up becoming de-facto standards.
Reason 3: Get things done(aka real Community)
You can see core developers going and adopting various other applications to their latest change in some underlying library. And there is also the opposite direction - developer spots a problem in one application and tries to fix it in the underlying library so it doesn't pops up in other places. This behaviour is what we heavily miss in Eclipse land.
How many of us use internal/non-api packages and don't help the other project to properly define an api?
How many of us has copied code from another eclipse.org project and let it stagnate there?
How many of us actively removed deprecated stuff (commands vs. actions, etc.) ?
How many of us started using underlying libraries stuff instead of our home-grown classes?
How many of us has tried to fix the problem in the underlying platform bundle when we spot one (swt anyone?)?
I know everything is not perfect in Gnome land and my statements are pointing the good parts only but that's what we have to point out, right? Instead of pointing failures (they are always obvious), people need to point out what others are doing better than them so we can all improve.
Whatever people might say about Gnome - as a developer I can only say that they are on the right path and sooner or later the technical excellence will pay off.
P.S. I'm a years long KDE user but I seriously consider moving to Gnome 3.6 as it fixes one of my last concerns (notifications) and Gnome Shell really really has the best work-flow for my taste.
If you are a Linux developer you already are aware of the beauty that some devel packages provide - their gtk-doc generated documentation. Or maybe you have been using it's online variant (e.g. cairo manual). Or you might have used Devhelp to search and read the documentation coming from your locally installed devel packages.
Now if you are using Eclipse for your development the very same documentation is integrated into Eclipse Help Center together with all the other documentations available there, you can read it there.
Or you might want to have it opened side-by-side while coding.
Pick your style and enjoy! Hopefully this brings the documentation closer to more developers. We all know how hard it is for everyone to read documentation so the easier to read it the better for everyone :).
Recent RPM versions include the concept of dependency generators. This opens the door for a number of automations and simplifications for people using RPM as their distribution format.
In Fedora we stepped in and worked on making Java land fell less of an alien in Linux distributions.
Not every OSGi feature is considered because some of them don't match with the goals of distributing a single project. Everything is based on the Bundle-SymbolicName and Require-Bundle headers (for now).
Bundle-SymbolicName header is used for generating a virtual provide for the rpm the bundle is part of in the format Provides: osgi(bundle-symbolicName) = bundle-version . This is done for every OSGi bundle in the RPM so the number of these provides will be the same as the number of bundles in it. This provides generation was enabled early in the Fedora 17 development phase and will be available for use in the soon to be released Fedora 17. How will this improve the packager's life one may ask? - Do you know which package e.g. javax.servlet bundle is in? You don't have to anymore. Put Requires: osgi(javax.servlet) in your spec file is all you need. Or you can use yum to query for it `repoquery --whatprovides "osgi(javax.servlet)"`
Require-Bundle headers are used for auto generating requires so people don't end up with dependencies not being installed. The format used is pretty much the same Requires: osgi(bundle-symbolicName). Few things needs mentioning here - optional requires are discarded because RPM(in Fedora) doesn't have the concept of soft-requires and versions are not added to the requires for a reason that will be explained later. The requires generator have just been enabled in Rawhide(future Fedora 18) and up to now it's showing no major problems with a pretty huge test case - the Eclipse SDK.
Import/Export-Package is a huge part of the OSGi specification and even the recommended way for specifying dependencies. Here I'll explain why it doesn't make sense for RPM packages without questioning it's general usability, it just doesn't fit our workflow.
having provides/requires for every package import/export is way too verbose and will polute the rpm metadata that much to make it hurt every user with unneeded time to download metadata
we don't want multiple providers for the same package - we want a single, stable and well tested provider.
This is big enough difference to even make me think of Step 2 where Import-Package headers are used at build time to map them to Require-Bundle. This will not be an easy task but it is possible because at build time we know which bundle exports the needed package.
Now to not having versions in requires. First of all there is no easy mapping between OSGi version ranges and RPM. OSGi recommends using version ranges while in RPM it's considered a really bad practice to use anything else but setting the lowest version supported. Second, we usually have only one package that provides given osgi bundle. Third , more than one OSGi bundles are usually grouped in a single RPM. All of the above combined makes the requires generated satisfying 90 % or even more of the cases and for the rest one can still add the requires manually (like we do now).
This isn't by any mean a complete solution it covers only the most common case but still it will prevent a number of problems like Eclipse failing to provision because of missing requires for some plugin and etc. Once the current automation makes its way through the whole distribution work on the next integration step can continue because there would be less time spend on simple but timeconsuming things.
There is a huge thread about "Moving Tomcat to Maven" and in this post there will be thoughts from Linux packager POV (with Fedora specifics).
The Big Question - " To Ant or To Maven" ?
It really doesn't matter from a Linux distribution POV. We build everything from source and the simple truth is that none of them is usable for us without the other. Maven dependencies are built with Ant and Ant dependencies are built with Maven. So we have both and support both.
What will be the benefits for us?
Maven support is getting better and better with every release and a lot more simplifications are in the work. All of these thanks to standardizations brought by Maven, to name a few there is work to automate rpm dependencies based on the Maven metadata, automation of packaging work and etc. Another possible simplification can be if mavenization is made in such a way that the implemented specifications (servlet, jsp, el ) can be build without the rest of Tomcat in a simple and obvious way. Currently in Fedora land we use Tomcat's implementation everywhere and the fact we have to build the whole Tomcat creates a number of unneeded build cycles.
What will we lose?
Usage of Maven will create additional build cycles because of the specifications jars and theirs excessive usage in Maven and friends. This will make packagers life even harder. If switch to Maven happens please consider the specification jars separation.
OSGification?
Making Tomcat's jars proper OSGi bundles is not something Geronimo specific.In the Eclipse land we use Tomcat artifacts too but they are always with added OSGi metadata. I really don't see how can this influence build system choice because we are really speaking about few tags in MANIFEST.MF. It's so easy to write them manually or if you want to automate the task there are both tools for Maven(maven-bundle-plugin) and Ant(osgi-bundle-ant-task). It would be really helpful in Tomcat devs maintain this part.
Other build systems?
Someone mentioned gradle as possible alternative or even as the best of both worlds. I guess it depends on the POV but in mine it's the worst of both worlds and there is a reason why it's not available in Fedora. Tomcat is critical enough piece of the Java infrastructure to stay on something common and proven and there isn't anything else but Ant and Maven that is widely spread.
P.S. If any Tomcat developer reads this one - feel free to ignore my thoughts but please post it to mailing list so other developers can consider it.
Jakarta project is retired. We won't miss you as you still live in the form of Ant, Apache Commons, Lucene, Maven, Tomcat and numerous others.
This project(and it's contributors) deserves a lot of respect as this was the front office of open source in the Java world. While there were numerous other project spending their time on pure opensourcing of Java in the corporate Java world it was Jakarta that enlightened people.
There are so many Java developers for whom:
ant is the first build system they have used
tomcat is the first web container they have deployed to
struts is the first web framework they have used after pure jsps
log4j is the first logging tool they have used
I'm definitely one of these guys!
Hats off to Jakarta contributors - you have changed the Java world!
Recent thread on fedora-devel provoked this blog post.
Fedora's "Freedom, Friends, Features, First" pillars seems to be missing the most important one FUN. (Courtesy of Pierre-Yves aka pingou )
Hopefully noone would question that the most important thing for a volunteer based project is "to be fun for the contributors". And being fun for contributors means that no contributor can give orders nor to treat another contributor to remove his access or something like this.
This is the way down. Everyone should do whatever is fun for him and if it's not fun for him/her and doesn't consider something as important he/she is not obligated to do. If someone else consider it's important please stand up and do it and stop thinking that others are slaves having to obey orders.
Most people I know started working on FOSS because of the FUN part.
To speak personally I haven't started because I want to give someone something for free but because there are people we can share knowledge, work together and have fun doing it.
Every effort to give people orders is ruining the 1st PILLAR of FOSS - FUN.
I forgot to announce the Linux Tools 0.9 release. Please check the New and Noteworthy for details. There a number of fixes and enhancements in the RPM related tools. As part of it we changed Manpage viewer plugin's bundle id and forced me to release new ShellEd.
Latest ShellEd is restoring compatibility with Manpage viewer and fixes an outline issue with DLTK 3.x. Also you can try the new update site. Note that this release will not work with Linux Tools releases prior to 0.9.
After really long wait ShellEd got really tired waiting for me to release it and run out in the wild ! Now seriously - I pushed the tag by mistake while playing with maven-release-plugin and byte the bullet to finish the release after that Read the release notes, go download it and install it. If we continue receiving bug-reports with detailed analysis and/or patches 2.0.1 will be out soon too. Fedora users expect the update in Fedora 16, the brave ones already have it in rawhide.
Chris has asked for "concrete example" showing the real story behind my previous post. My example will be Tycho IP review. (Note: I'm an outsider to the whole process but I'm dealing with a lot of Maven/Eclipse/Tycho issues in Fedora).
Here is the bug with a lot of info in it. And now let's show the amount of changes that happened to Tycho codebase after this bug was open. I'm not sure that all of these changes are thanks to the project moving to Eclipse.org but I'm pretty sure that most of them are provoked by this and commit messages as this one seems to prove me right.
Even the first few comments are showing that with the start of the review licensing has been fixed in a number of places. This might not look important to pure Java guys but issues like that are showstoppers if one wants to use this tool for something shipped with Fedora or Debian (the two distros with biggest influence on Linux developers). Examples here, here, here, here and here.
No more checked binaries in the scm. Examples here and here.
Cleanup dependency chain. The biggest sin of almost every java project! Examples here, here, here and here.
Do not duplicate code/functionality. Examples here, here and here.
Some of the examples are falling in more than one group but they are mentioned in one place only, decide for yourself whether they apply for others too. Also note that these examples are taken only from git log so one may even think that this is just the top of the iceberg or that could have happened without Eclipse being involved at all. But there is evidence that at least few of them are thanks to it.
P.S. Tycho devs - keep up the good work - you have really made a huge change in the Eclipse ecosystem and I really appreciate your efforts. You are just the most recent show case for this post. :)
P.S. 2 If someone tries to say that these problems are only in certain projects I would ask him/her in advance to give us the URL of his project so others can point similar problems.
We all do these mistakes and that's where we need help of entities like the Eclipse Foundation.
The Hudson proposal to move to Eclipse started a big discussion about the Eclipse Development Process, IPLog/IP team and etc. A lot of people are complaining about the amount of work they have to do but having done few Eclipse Linux Tools releases I don't find this work that much, probably it hasn't costed me more than a day with non technical issues. Now I plan to explain why is to so awesome to follow this process and respect it (note that I'm a Linux distro guy so I'm heavy biased):
every single bit is properly licensed - One can not imagine how many times we(Fedora) have reported/asked upstreams to at least put some license to their work! And this is a blocker for inclusion in the distribution and we have spend a lot of time patching out such bits and dealing with the consequenses of these actions. +1 for the Eclipse process here
incompatible licenses are not used/shipped together - One might think that this is just to make lawyers happy but this is only half the truth. It is also about respecting authors wish - if I choose to license my work under BSD I want people to use my work whenever they found it possible but if I choose to license under GPLv3 my primary goal would definetely not be the same and I would care most for people giving back. Most probably library developers would not gonna sue you for using incompatible licenses but this is pure DISRESPECT TO THEIR WORK. I can name a huge number of Java projects that don't even understand that. +1 for the Eclipse process too
reduce duplication (side effect) - One of the recent reviews of the IP team made one project remove code that was already done in one of its dependencies. Most probably just to not bother with getting it IP clean. I don't know what would readers think but this is pure technical win!
remove unneded dependencies (side effect) - Same review as the previous point - a number of unneeded dependencies were removed just to not bother with getting it IP clean (if possible at all - read the first point). And the build was failing without these deps despite them being unused/unneded. Another pure technical win thanks to the IP team!
There are a lot of other benefits that can be mentioned but just the first two are making us - Java packagers(I'm sure I speak for at least few others) want every Java project to go through similar process. This would make packaging Java software a lot easier, a lot more acceptable and not that allien on Linux systems.
Kudos to Eclipse's IP Team
Everyone actively working on some Java project - think whether you want your software to be included/shipped to a lot of users. You may achieve that yourself but having a team helping you in this is definetely helpfull.
P.S. Links and people/project names are intentionally not used to prevent someone getting it personal. :)
Have you wondered what package provides certain Maven artifact?
If you answered yes to at least one of the questions there is a good news for you:
Fedora's build system is going to automatically generate RPM Provides in a sensible way for Maven developers.
Now the details. Big thanks goes to the RPM developers for the new Dependency Generator which has made our work so much easier.
With just these 2 simple files maven.attr and maven.provwe get it to the state where every package that installs pom files according to Fedora Java Packaging Guidelineswill get provides added for every pom installed in the form mvn(groupId:artifactId)where groupId and artifactId are the same things you know from your Maven experience. Look at this recent maven2 rebuildfor example what will be generated for a package with many pom files installed.
It might look a small thing but I'm really looking for the day when I'll be able to write BuildRequires: mvn(org.apache.maven:maven-script-ant) and not having to guess whether this is part of maven package or maven-plugin-tools-ant or maven-shared-ant. And these days are near for rawhide when we get the critical mass of rebuilds done so the provides are in place.
This opens an enourmous opportunity for improving a number of things like:
* when you get a build failure in your maven build - you should be able to just write yum install mvn(groupId:artifactId) and have the package ready. Who knows we might even find someone to create a PackageKit extension in the way bash command-not-found is acting?
* tools like RPMStubby will be able to generate proper BuildRequires section without guessing how did the distribution renamed the package
* use your imagination
There is a possibility to add similar support for the requires generation but lets first do all the fixes/simplification this one gives us.
Happy packaging to all Java and Maven packagers!!!
and while the hardware seems good I’m a bit disapointed on the software side.
There is at least one bug which is clearly visible - pedometer counts calories twice
when it’s on and exercise mode is started.
introduces startup founders and employees to the “Bullseye Framework,”
a five-step process successful companies use to get traction.
This framework helps founders find the marketing channel that will be key to unlocking the next stage of growth.
-
to learn how to make products (especially mobile apps) that customers keep using on their own without
additional external marketing (
-
lean product development (
by Timothy Ferriss is one of my all time favorite books.
The basic idea is to ditch the traditional working environment
and work less utilizing more automation.
by Dale Carnegie teaches you how to deal with people. The book briefly explains
some easy to use principles, why and how they work and then provides tons of
real life examples behind those principles. This book is a must for everyone but
especially parents and teachers and folks in sales, management or business leaders.
with Android. The burst
mode feature there is particularly crappy. It shoots between 20 to 50 photos
(haven’t counted how much exactly), then takes a second to flash everything to disk,
then pops a question asking the user to select the best one and possibly delete
the rest. If you don’t want all of this just tap the back button to return to
shooting mode.
as the one shown here. It had troubles connecting to the upstream Wi-Fi router
because it used MAC filtering instead of password security. Luckily there was
a 
This is what my hall looked like at around 10:00 and stayed pretty much the same
during the entire day.
and all I have to say is “I want to be a robot”!
is the second book I read on the subject after first reading
by Peter Hook is one of my favorites. It covers a great deal of music and clubland history,
depicts crazy parties and describes the adventure of owning one of the most
popular nightclubs in the world. All of that while struggling to make a buck and
pouring countless pounds into a black hole.
by Hans Jürgen Press is a very old book listing 200 experiments which you can
do at home using household materials. It is great for teaching basic science
to children. The book is very popular and is available in many languages
and editions - just search for it.
.
It’s a child’s book telling the story of two kids whose fathers are rival
robbers. The book is an easy read (2-3 hrs before bed time) with stories
of magic woods, dwarfs and scary creatures mixed with human emotions
and the good vs. bad theme.
by Ray Kurzweil.
are cheap and portable but don’t look very well around the edges.
