Posts Tagged ‘structure’

On God and computers and how computers copy God’s creation

Friday, October 25th, 2013

People are copying Gods creation the-tree model people don't invent they copy

I've been thinking for a long time. How computers and involved technology copy God's creation. This kind of thoughts poped up in my mind right after I became a believer. As I'm having a strong IT background I tend to view thinks in world via the prism of my IT knowledge. If I have to learn a new science my mind tend to compare how this translates to my previous knowledge obtained in IT. Probably some other people out there has the same kind of thinking? I'm not sure if this is a geek thinking or it is usual and people from other fields of science tend to also understand the world by using accommodated knowledge in field of profession they practice. Anyways since my days I believed in Jesus Christ, I started to also to compare my so far knowledge with what I've red in Holy Bible and  in the book of The Living of Saints (which btw is unknown to most protestant world). It is very interesting that if you deeply look into how all Information Technology knowledge is organized you can see how Computers resembles the visible God's creation. In reality I came to realization how Moden Man self-deceives himself. We think with every new modern technology we achieved something new revolutionory which didn't existed before. But is it really true? Lets take some technology like Microsoft Active Directory (using LDAP) for example. LDAP structures data in a tree form where each branch could have a number of sub branches (variables). In reality it appears LDAP is not new it a translation of previous already existent knowledge in universe served in a different kind of form. Let me give some other examples, lets pick up the Internet, we claim its a new invention and from human point of view it is. But if we look on it via the prism of existing created world. It is just a interconnection between "BIG DATA" in real world it is absolutely the same latest researches already know all in world is data and all data in world is interconnected. So obviously the internet is another copying of the wonderful things God created in material and for those who can accept (the spiritual world) world. Many who are hard-core atheists will argue that we copy things in the world but all the material world is just a co-incidence. But having in mind that the world is so perfectly tuned "for living beings to exist" it is near to impossible that all this life and perfection emerged by random. The tree structure model is existing everywhere in OS and programming. We can see it in hiearchy of a file system, we can see it in hashes (arrays) in programming and all this just copies the over-simplified model of a real tree (which we know well from Biology is innemous times more complex). Probably the future of computing is in Biotechnologies and people's attempts to copy how living organism works. We know from well from science-fiction and cyberpunk the future should be mostly in Bio-technologies and computer as we know it but even this high-tech next generation technology will be based on existent things. Meaning man doesn't invent something so different he does copy a model and then modify the model according to environment or just makes a combination of a number of models to achieve a next one. Sorry for the rant post but I'm thinking on this for quite a while and I thought i should spit it here and interested to hear what people think and what are the arguments for or against my thesis?

How to solve ALSA sound problems with old Linux programs and games depending on (OSS)’s /dev/dsp / fix wine games and pulseaudio problems – My few thoughts on OSS and ALSA

Wednesday, January 11th, 2012

ALSA OSS Pulseaudio ESD Some fixes workaround to gnu linux audio messI remember GNU / Linux, 11 years from now, times when ALSA was not standardly shipped with Linux.
Back then ALSA still lacked good support for many SoundCards and was still a "baby project".
In that time what we used to have sound on Linux was OSSOpen Sound System. OSS emerged right after the first ever Linux sound system VoxWare (formerly known as the Linux Sound Driver).

Back in those days OSS was used for multimedia support on both GNU / Linux and BSD based free OSes. It was few years later when I heard and used ALSA for a fist time and it wasn't really a love from first sigth.

One can easily find out by the name ALSA it is a system especially built for the Linux kernel and that's one of the reasosn why *BSD systems has their custom separate sound system.
There is plenty of reasons why OSS was substituted with ALSA. Main reason was its commercial like license, OSS wasn't completely "open source" GPLed (free software), there was resctions on use of OSS for commercial goals.

With its emerge ALSA started to push away OSS slowly. Somewhere in 2003, alsa has officially entered the Linux kernel source and until 2005 it was the default standard for all GNU / Linux operating systems.

As of time of writting ALSA has become the only sound system to have support for multiple sound card devices for Linux.
My experiences with ALSA, however ain't so nice if I take a look in my past experiences.
Since the very beginning of using ALSA, I had plenty of troubles with configuring properly my sound card not to mention, even after configuring it the MIDI support was not there.
Besides all the troubles main problems were stemming from the many applications still written to use OSS as sound system and hence with those sound was impossible with ALSA.The most problematic thing about apps written with OSS in mind was all of them tried to stream sound via /dev/dsp (OSS Digital Sound Processor), since alsa did not used /dev/dsp those programs was soundless.

On the other hand OSS was creating issues as well, one severe problem with OSS was the inability to stream multiple sounds simultaneously, because each sound stream required to pass voice through /dev/dsp and usually there was only one /dev/dsp.

The message;

/dev/dsp: Device or resource busy
and the proceeding irritation that used to annoy us in the early GNU / Linux days had of course some raw workarounds hacks but generally the workaround did not fix problems always.

Introduction of alsa free us from /dev/dsp issues but on the other handy has created a whole ocean of new BIG problems …
ALSA has modular structure and this imposes a great problem nowdays. The modular architecture is generally a good idea, however the way this was implemented within ALSA is far away from clear and easy to understand by the end user and therefore makes it very unintuitive and obscure.
Alsa misses simplicity which somehow was partially in the days of OSS. Thinking over the general situation with Linux multimedia nowdays, I believe it was exactly ALSA Project responsible for the so delayed mass Desktop Linux adoption.

Many long year standing Linux users had certainly had the alsa troubles during new system installs (correct me if I'm wrong).
The only fix to multiple soundcard initialization problems was to download alsa source and compile from source and hence made it hard and discouraging for people giving Linux a try.
This kind of ALSA "brokenness" pattern continues even to this very day (in Debian) Linux and probably building the alsa system from source is among the good practices to have a functional Linux sound system…

With all said the historic reason why ALSA was not quickly adopted and still is not a preferred default system for many applications ported to Free Software OSes by commercial company vendors is clear. Its simply not working out of the box …

Hope some ALSA developers will read this post work on changing the crazy structure of ALSA over complexity. ALSA needs automate way to solve issues with itself, the configuration should be more trivial and unified if Linux has to become more attractive for Desktop adoption.

Anyways, after the few words of history and indicating my pesonal observations on ALSA. I will proceed and explain few things on how ALSA can be configured to support and play nice with OSS dependant programs as well some basic explanations on common incompatibility between esd and pulseaudio and how this can be fixed;.

To assure nowdays OSS API built programs and games would work with Alsa its necessery to have installed;

ALSA wrapper for OSS applications

On Debian, Ubuntu, Fedora and most Linux distributions the Alsa OSS compatability layer comes under a (deb / rpm) package named alsa-oss

To install OSS compatability on Debian, Ubuntu and the like Debian based distributions issue:

debian:~# apt-get install alsa-oss alsaplayer-oss
...

On Fedora and other rpm based distributions install is with:

[root@fedora ~]# yum install alsa-oss alsaplayer-oss
...

alsa-oss provides with a command called aoss that should be used to work around some issues with old applications still depending on OSS:

hipo@debian:~$ aoss programName

Using aoss is helpful especially in situations if you have to run programs which deal with MIDI and others which somehow want to use /dev/dsp

There is also alternative way to enable alsa native support for MIDI and OSS by loading 3 kernel modules:

debian:~# modprobe snd-seq-oss
debian:~# modprobe snd-pcm-oss
debian:~# modprobe snd-mixer-oss

Note! The three modules has to be separately build using kernel source at most cases and does not come with most Linux distributions, so on many installations (including my current), they will be missing. If for you they load properly or you have customly build them add them also to load on system boot, like so:

echo 'snd-seq-oss' >> /etc/modules
echo 'snd-pcm-oss' >> /etc/modules
echo 'snd-mixer-oss' >> /etc/modules

The Linux sound situation becomes even more messy when ESD enters the scene. Many of the novice new Linux users certainly don't remember (Enlightened Sound Daemon) . ESD historically preceded PulseAudio . Hence it will be good to mention ESD was used for few years in GNOME and in around 2006-2007 it was substituted by PulseAudio.
Many applications, however who was ported or written for Linux especially (the proprietary ported ones) was already built to work with ESD and even though newer GNOME releases was fully using pulseaudio, this (non free software apps and games) were still depending on ESD.

The situation was partially fixed by creation of module for pulseaudio which added emulation support for esd . This was done by a module library for pulseaudio called libprotocol-esound.so
The package for almost all Linux distributions which does the esd emulation via pulse is pulseaudio-esound-compat . In latest Fedora Linux pulseaudio-esound-compat is installed by default.
In Debian and other Linux distributions it might need to be installed via apt with;

debian:~# apt-get install pulseaudio-esound-compat
...

pulseaudio-esound-compat solves some of the ESD app incompability but not always …
Handy tool also worthy to mention in solving PulseAudio, OSS incompatibility issues is padsp

padsp is helpful in solving obsolete issues with OSS applications (trying to access /dev/dsp) and therefore unable to communicate with Pulseaudio
padsp – is a PulseAudio OSS Wrapper.

An example where padsp is helpful is in case of /dev/dsp errors like:

/dev/dsp: Device or resource busy
Could not open /dev/dsp

Another common problem with sound on Linux is when running windows applications (running windows games with wine).
Quite often sound fails to work since wine tries to directly communicate with alsa and fails because alsa sound channel is taken by pulseaudio.

To workaround wine issues with pulseaudio, one of the solutions is to temporary stop pulseaudio, before running the wine emulated application:

hipo@debian:~$ pulseaudio --kill

Later on when the windows wine emulation is completed, pulseaudio has to be started once again in order to make Pulseaudio applications produce sound again, e.g. one has to issue:

hipo@debian:~$ pulseaudio --start
Alternative way to workaround wine sound issues is by using a script to kill pulseaudio every second. Here is fix_pulseaudio_wine_sound_probs.sh script

This script was reported by many people as fix to problems with wine games failing to play sounds and music, anyhow I personally prefer using the stop / start pulseaudio method.

The picture below is taken from Wikipedia and illustrates, clearly the intergalactical complexity of sound systems on Gnu / Linux and BSD

I just hope one day this (OSS, ALSA, esd, Pulseaudio) mess will be over! In the mean time I hope my suggested work arounds helps someone. If someone has a better more unified script or solution please share in comments

How to list and exclude table names from a database in MySQL (exclude table names from an show tables in MySQL) by using information_schema

Wednesday, March 30th, 2011

Listing all table names from a MySQL database is a very easy and trivial task that every sql or system administrator out there is aware of.

However excluding certain table names from a whole list of tables belonging to a database is not that commonly used and therefore I believe many people have no clue how to do it when they have to.

Today for one of my sql backup scripts it was necessary that certain tables from a database to be excluded from the whole list of tables for a database I’m backupping.
My example database has the sample name exampledatabase and usually I do list all the table contents from that database with the well known command:

mysql> SHOW tables from exampledatabase;

However as my desire was to exclude certain tables from the list (preferrably with a certain SQL query) I had to ask around in irc.freenode.net for some hints on a ways to achieve my exclude table goals.

I was adviced by some people in #mysql that what I need to achieve my goal is the information_schema mysql structure, which is available since MySQL version 5.0.

After a bit of look around in the information_schema and the respective documentation on mysql.com, thanksfully I could comprehend the idea behind the information_schema, though to be honest the first time I saw the documentation it was completly foggy on how to use this information_schema;
It seems using the information_schema is very easy and is not much different from your normal queries syntax used to do trivial operations in the mysql server.

If you wonder just like I did what is mysql’s information_schema go and use the information_schema database (which I believe is a virtual database that is stored in the system memory).

For instance:

mysql> use information_schema;
Database changed
mysql> show tables
+---------------------------------------+
| Tables_in_information_schema |
+---------------------------------------+
| CHARACTER_SETS |
| COLLATIONS |
| COLLATION_CHARACTER_SET_APPLICABILITY |
| COLUMNS |
| COLUMN_PRIVILEGES |
| KEY_COLUMN_USAGE |
| PROFILING |
| ROUTINES |
| SCHEMATA |
| SCHEMA_PRIVILEGES |
| STATISTICS |
| TABLES |
| TABLE_CONSTRAINTS |
| TABLE_PRIVILEGES |
| TRIGGERS |
| USER_PRIVILEGES |
| VIEWS |
+---------------------------------------+
17 rows in set (0.00 sec)

To get a general view on what each of the tables in the information_schema database contains I used the normal SELECT command for example

mysql> select * from TABLES limit 10;

I used the limit clause in order to prevent being overfilled with data, where I could still see the table fields name to get general and few lines of the table to get an idea what kind of information the TABLES table contains.

If you haven’t got any ecperience with using the information_schema I would advice you do follow my example select and look around through all the listed tables in the information_schema database

That will also give you a few hints about the exact way the MySQL works and comprehends it’s contained data structures.

In short information_schema virtual database and it’s existing tables provides a very thorough information and if you’re an SQL admin you certainly want to look over it every now and then.

A bit of playing with it lead me to a command which is actually a good substitute for the normal SHOW TABLES; mysql command.
To achieve a SHOW TABLES from exampledatabase via the information_schema info structure you can for example issue:

select TABLE_NAME from TABLES where TABLE_SCHEMA='exampledatabase';

Now as I’ve said a few words about information_schema let me go back to the main topic of this small article, which is How to exclude table names from a SHOW tables list

Here is how exclude a number of tables from a complete list of tables belonging to a database:

select TABLE_NAME from TABLES where TABLE_SCHEMA='exampledatabase'
AND TABLE_NAME not in
('mysql_table1_to_exlude_from_list', 'mysql_table2_to_exclude_from_list', 'table3_to_exclude');

In this example the above mysql command will list all the tables content belonging to exampledatabase and instruct the MySQL server not to list the table names with names mysql_table1_to_exlude_from_list, mysql_table2_to_exclude_from_list, table3_to_exclude

If you need to exclude more tables from your mysql table listing just add some more tables after the …’table3_to_exclude’, ‘new_table4_to_exclude’,’etc..’);

Of course this example can easily be adopted to a MySQL backup script which requires the exclusion of certain tables from a backed up database.

An example on how you can use the above table exclude command straight from the bash shell would be:

debian:~# echo "use information_schema; select TABLE_NAME from TABLES where
TABLE_SCHEMA='exampledatabase' AND TABLE_NAME not in
('mysql_table1_to_exlude_from_list', 'mysql_table2_to_exclude_from_list', 'table3_to_exclude',);"
| mysql -u root -p

Now this little bash one-liner can easily be customized to a backup script to create backups of a certain databases with a certain tables (e.g. with excluded number of tables) from the backup.

It’s seriously a pity that by default the mysqldump command does not have an option for a certain tables exclude while making a database dump.
I’ve saw the mysqldump exclude option, being suggested somewhere online as a future feature of mysqldump, I’ve also seen it being reported in the mysql.com’s bug database, I truly hope in the upcoming releases we will see the exclude option to appear as a possible mysqldump argument.
 

Farting all the day

Tuesday, February 20th, 2007

Can’t stop farting terribly the whole day :] Yesterday I ate tons of food without thinking I’ll suffer in the morning.I woke up with terrible acids in the stomach. It’s like the sin. When you sin again and again you don’t realize sinleads consequences after him body suffering illness and death in the end both spiritual and physical. My daystarted terrifying. I was feeling cold most of the day. I have a bad blood movement so it’s very usual for me to feel cold.I hate this coldness! I went to the college for an hour it happened I have hour after 1 hour. I was almost ready to sleep walking.Today I’m terribly sleepy. On my home I met “Narf” a collegue in the college who is an IRC maniac and linux fan also :]. He proposedto drink coffee. So we spent an hour on a coffee. He explained me about the structure of the IRC in general it seems the backbone of the UniBG irc is debian.spnet.net. After an hour we went to the college but it seems like our English class was not after an hour but 2 hours, again the dumbs mismatched The Schedule. Nomen was infront of the college and we drunk coffee together on the fountain. I had Introduction to Management after the Business English. My classes ended in 15:45. I take Habib and we went home and discussed his plans about his future. He have plans to fly for UK if they approve him for Visa and make some money to be able to pay his taxes. After that Nomen come home we played MAMEs. A very commical situation was in the midday when I was with Nomen infront of a food kiosks, he was wayting for his snack, suddenly I farted terribly :]]. And we started laughing cause it smelled very brutally :]] I have peace almost the whole day. And I feel God’s love through his holy spirit. Thanks Lord Shabbaoth glory be to your Holy name Father!END—–