Eric's /dev/blog

Filter generator

2006-04-18T08:54:00.000-04:00

Found an interesting filter generator on the internet :

http://www-users.cs.york.ac.uk/~fisher/mkfilter/trad.html

It's a really nice application, it even generates C code to implement your filter !

FFT for digital filtering (DSP) applied on.. images ?

2006-04-08T19:37:00.000-04:00

Today while looking on the web for information about digital filters, I found this guy who is using FFT (fast fourier transform) on images, and use DSP techniques typically used in equalizers and other devices on image processing..

The resultats are really impressive !

http://gilemon.free.fr/site-rapport/rapportfiltrage.htm

1% more for 100% more ?

2006-03-23T22:29:00.000-05:00

For thoses who knows, escrow.com is a service that protect buyer and sellers in an online auction from fraud. To check the transaction fee escrow.com is charging, they've set up a little javascript calculator
However, if you enter the value :
1010101010101010

It returns the same amount as if you entered 0$, that is the base fee of 25$.
However try it for a smaller number.. like 1000$, you will see it doesn't reflect at all the reality.

I know that it is a really big amount of money, and probably no internet transaction will be made through that service, however, I think a basic point of software engineering is : testing. This internet calculator is only an example of what I try to talk write about.

People in the industry really don't test enough their products : softwares, cars, hardware, and others !

What makes me the most sad : softwares are relativley easy and cheap to test. To test a motherboard, the motherboard compagny need to buy a test bench (several hundred thousands dollards), pay an engineer to write a test plan, than pay a guy who is specialised in test bench programming to write a program that will test this particular motherboard line ! The chances are the process will be to do again on the next motherboard line.

In the software industry, you don't really need to test each individual units. Yes, you need to test the CD for non defectuosity if the software is transported on a CD, but if the software is transported on electronics way (internet), the testing is done via MD5 automaticaly..

All this to say that, since you don't really have to test each individual units of software you distribute (the reproducability ratio of a program copied is really high.. if you copy the same file twice, both file should really looks alike), the cost of your individual tests is really really decreased.
However, why do people still continue to distribute badly tested applications (many examples, not limited to microsoft, but also including solaris x86 bug with usb mouse and keyboard layout in java applications, and multiple others) ?

I cannot answer this question. For shure, time to market of software is a great constraint. However if testing is done from the beginning to the end of the developpement project, time to market is unaffected, you just need to hire more people, maybe 3-5% of your developpement staff, and dedicate them to tests, from the beggining to the end of the project.

5% of your staff. If you have 100 developpers, that means hire 5 people. Per years, that represent about a quarter a milion dollards, I know that. However assuming the testers are paid equally or less than most of your developpement staff, 5% of your staff means less than 5% of your developpement cost, which represent 0-5% of your project costs, and that should represent a lot less than 1% of the sale price.

On the other hand, the testing cost of a motherboard, including the additionnal cost caused by deffective units, is more than 1% of the total sale price.

On the other side, if you are a company using that software, and one of your employee just lost 2h of work (40$, assuming employee is paid 20$ per hours) because of a computer bug, that usually represent more than 1% of the price you paid for that product.

Are people willing to pay 1% more to get 100% better products ? I think so.

Why isn't that practice implemented in the industry ? Well it's on his way, with concurrent engineering making his way and with the obligation to get a PDP (product developpement product) (which we hope will contain extensive tests) in order to get iso 9001:2000 certified, I hope soon I will be able get higher quality softwares.

Memory leak mesurement

2006-03-16T18:23:00.000-05:00

This week we had a little problem with our term project; we had a few leaks; and overally the memory usage by the application was increasing of 20mb/s, on a 2gHz computer. On a 1gHz computer, the leak was growing about 10mb/s.

Why not create a standard unit to mesure a memory leak amplitude ? Well since it's hard to mesure a "leak", let's mesure how much memory usage of a program grows in time.

Here is my proposition.. Assuming we have sleeps or wait for user input, 1E is : the program grows 1mb in memory per seconds, per gHz..

I don't think that proposition will be accepted by the ansi or iso comitee tomorrow.. but well.. Maybe some day the E will become as famous as the smoots : )

Are you that paranoid ?

2006-03-07T21:36:00.000-05:00

Are you that paranoid about your passwords ??

Error Message: Your Password Must Be at Least 18770 Characters and Cannot Repeat Any of Your Previous 30689 Passwords

This is a real error message ;
http://support.microsoft.com/kb/276304/

Wow ! Free servers for 2 months

2006-02-22T21:34:00.000-05:00

This is really the first time I see a such offer in the hardware industry. In the software industry we always see offers such as "free for 15 days" or usually, "free for 30 days".

Sun recently came up with a quite weird offer.. They send you a free server for 60 days, and if you don't like it you call them and they send someone to pick it up.

We aren't talking about some crappy boxes.. we are talking about coolthread servers ! Probably the fastests servers for java applications and multithreaded applications (and low fp applications.. like mentionned in the contract.. you cannot test this server for 60 days to use it with an heavy-fp application hehe)

Here is the link if you are interested : https://www.sun.com/secure/servers/coolthreads/tnb/qualify.jsp

I want to work there

2006-02-22T21:32:00.000-05:00

Times magazine published some pictures of the google headquarters. Yeap, I definatly wants to work there :
http://www.time.com/time/photoessays/2006/inside_google/

A billion maze !

2006-02-22T21:29:00.000-05:00

A friend of mine Alexandre sent me this link today :

http://www.onebillionmazes.com/

This site claim to have exactly a billion mazes ! I can't really believe they really have a billion of different mazes tought.. The funnieset thing is probably.. where do they put all theses mazes ! 24k per mazes.. A bilion mazes.. Figure it out, it gets to about 20 tb !

That is a lot of storage for a small budget website !

No.. really.. there is something weird with this website

Open Letter to Logitech

2005-09-12T08:48:00.000-04:00

To Logitech folks,

I've been a long time logitech buyer. Your products are always of good quality, but as soon as you begin to have problem, you can forget about support.
I first encountered really really bad support with an old steering joystick I had 4 years ago that broke, but continued to buy from logitech because theses products were great.

Logitech really don't seem in a hurry; they have been developping their driver for 2 month; still no sign of even a beta.
Hey, they don't even have to re-write it. If they did the 32 bit driver right; it's a simple recompile !!
Beside, they have known the venue of x64 for a long time; just look at other vendors and see logitech is way behind :
Creative offer 64 bit support for all his, including almost legacy, devices
Matrox support this platform for his devices old up to 4-5 years; right now.
ATI/NVIDIA offer full 64 bit drivers

Really, logitech, please, try to improve on quality of support. Try new engineering methods, like Concurrent engineering. Write your drivers in C; then you only have to recompile them to port them.
I don't know what's wrong; really. I wrote drivers for a couple of devices in a single days. Not for webcams, true. But I wrote drivers for photo sensors, en gines, and a couple other devices; with a small team doses stuffs are done really quickly.

Now, I will stop buying from logitech in a month if I don't get drivers for Logitech Cam PRO 4000
I will stop recommending theses products
I will stop implementing theses products in big LAN deployments

Please, hurry up development on logitech camera x64 bit driver. You don't have any excuses, Windows x64 have been up for several month, and it's API have been public for a while.
I think you now pay because you didn't wanted to support windows server 2003 (same kernel as x64; if some modifications needed to be done from xp to 2003 they need to be done before moving to xp x64)

Eric Boutin

Wow ! 1.7mbit for the price of 3 !

2005-08-26T21:48:00.000-04:00

Wow, just recieved my modem. It's a day late, but it's ok. Plug it in, bandwidth test, 1.7mbit. I pay for 3.
This ISP is called sympatico.

In my area, there is 2 major high speed isps :
-Sympatico which offer DSL and ADSL which is the service I get
-Videotron which offer cable distribution at 5 mbit.
Both are about the same price but videotron have limited banwidth usage (30gb) while sympatico is illimited. Beside, videotron is "shared" bandwidth, so if neighbord is downloading, it may gets a small impact. Sympatico brags to have the stablest bandiwdth because of dedicated access.
I experienced videotron, and yes, they have unstable bandwith. For example, at my other location I was with them, we paid for 5 mbit and had 4 most of time. However, the difference beetween both service is about 2$. 2$ for 2 more mbit, I don't think we can really talk much about it.

Really, don't go sympatico.

Try that on your single cpu workstation

2005-08-05T00:30:00.000-04:00

Try to zip a 4.5 gb folder while installing j2ee sdk and using netbean; and stay fluid.

That's what I've done successfully tonight. Really, SMP rocks, and no doubt replace thoses single core opterons by dual core opterons and you have quite of a boost.

It was actually funny to see one cpu works really hard while zipping the folder, while the second cpu was idle or about and was moving stuffs around and doing housecleaning.

Really friend James Dickens Once you go smp, you don't move back, you can write a script that unzip 4 bzipped2 iso (.iso.bz2) and then work then forgot them because you never really noticed that the system was working; so you don't really notice when it's finished.

Next desktop you guys buy, take this advice, go smp. It makes you stop wasting time waiting, or if you can't afford smp, go dual core, or dual core smp (2x2 cores) if you have more money

And don't make same mistake as me.. buy a motherboard with either a pci-e or agp bus; pci-x framebuffers cost heads, arm and legs

77 % !!

2005-08-04T00:22:00.000-04:00

I made it !
I made my box achieve a cpus usage of 77% !!

I was starting openoffice writer, gimp and netbean at the same time :)

Whishlist

2005-08-02T23:37:00.000-04:00

I recently built a wishlist of additions for my great new opteron box
- USB 2.0 Card, possibly with firewire controller too..
- Matrox G450 PCI or better PCI-X framebuffer.. but thoses are unaffordable
- Hard driver 250gb SATA x4
- 90mm fan x2
- 1gb RAM ECC 400mHz x2 (or x8 it would be better but I can't have everything)
- AMD OPTERON 275 x2
- DVD Burner
- 19" Monitor

Note that there is a priority.. the 2 AMD Opterons 275 won't be for this year, probably not for next year neither ;)
A framebuffer is becoming quite.. needed
90mm fans comes with the drives..

Storage is always good
Another monitor is always good, especially when you have a matrox framebuffer
USB 2.0 is to power my webcam.. it's quite sluggish because of the absence of usb 2.0
DVD Burner to make backups

That would create a system with specs like thoses :

2 Gigabit ethernets
1 10/100 ethernet
3 gigs of ECC 400 mHz ram with 128 bit read (or 8gb but.. maybe in 2-3-4 years)
ATI XL framebuffer (or.. shit)
Matrox PCI framebuffer (better)
4 cores of amd opteron 64 bit at 2gHz each (quad core system.. wow !)
1.12tb of storage
USB 2.0 controller
USB 1.1 controller
IDE bus (full)
SATA bus (full)

drooool !
I don't think it's... possible to build a better workstation than this one.. (I wrote workstation, not server ;) without starting to be excentric filling the system with the 32 gb of ram it can contain

Then I could add up an scsi PCI-X controller with a scsi array and a few internal drives; that could add up 73gb * 10 = 0.73tb of storage... approx 2tb of total storage...

Now the only improvement that will be possibly done leads me into the me into the workgroup server/midrange market (fiber chanel with fiber array and Alternate Pathing, hot swapping, clustering many boxes like this to distribute load, add a tape librairy to store up to 1200tb of data ( some plans to run yes during a long long time and archive all it's output ;) )

It's awesome the possiblities this boxe gives !

drooool

The power of two

2005-07-27T22:50:00.000-04:00

First, note that on this computer, no graphic acceleration is really present; the framebuffer just don't... support it.. That means DVD decoding is done by the cpu.

Second, note that this box is running windows 2003 x64 enterprise; which is, IMHO, bloated and really inefficient.

Here's the config of my box :
2x amd opteron 246 2gHz
1gb ram @ 400mHz (yeah I know.. that's little to feed two monsters.. more to come in next years)
slow drives
slow framebuffer

Here what's running on it.. perfectly fluently
2 terminal server connections
- One is running windows XP in a vmware, basicly idle, some basic tasks like word and so
- Another is running an idle firefox
On the console, a full screen DVD is playing perfectly fluently

450 threads running
8500 handles
60% cpu usage

That means I could play 2 full screen DVD, 2 vmwares, open a few words instance and a few firefox and it would still be fluid

Roles are changed

2005-07-27T18:50:00.000-04:00

Today my dual opteron system finally booted after a bunch of troubles with the motherboard. I had to ship it back to tyan and they shipped a new one back to me.

It's awesome how some changes are noticable and how roles are changed.

I've took the cdrom from my desktop (1.3gHz duron) into this box. It's the first noticeable change. Before this cdrom was quiet. Now it makes noise when working a lot. Why ? Because before, probably that this 52X cdrom was more than filling the system I/O, and was sitting idle. Now the system could eat 4-5 like this for breakfast.

Same thing for hard drive.

I couldn't have a chance to unleash the full power behind thoses 2 gigabit ethernet ports since... I don't have an ethernet switch....

Big change, vmware.
Before, you could tell when vmware virtual machine was running because the whole system was sluggish.

Now, I'm currently installing windows XP Pro in a vmware, and cpu usage is 15%, everything is responsive.
In other words, a few clients could run a vmware via ssh on this box and I'd never know unless I look at the process list.

The few things that really bugs me is.. lack of support for my printer (no 64 bits driver available ; this lead to a big question, why do windows drivers need to be compiled kernel compatible ?? it,s not a real driver, it's a printer !)
Lack of support for my webcam.

For thoses 2 reasons, I had to install windows XP pro in a vmware (printing and webcam)
Another thing that bugs me is lack of usb 2.0 support.

That * really * bugs me; I really don't understand why there is no usb 2.0 on this motherboard, I'll probably go and buy a usb 2.0 + firewire card; since thoses can be found for about 20$

I couldn't get sound support for my sound blaster Live ! but after some googling I found a beta driver on preview.creative.com

That's about it for a system that really really rocks

Day 7 : Web services exists and we're in 2005

2005-07-22T17:37:00.000-04:00

One of our data source in this project is a software that comes from la chambre du commerce immobilier du grand montreal and is called Edger. It is used to find sales that can be compared in order to make a more accurate evaluation of a property.

In order to make a fully integrable software, I emailed a person responsible for Edgar something like this :
I would like to know if I could import data from Edgar into our database in an easy way, or get the protocol Edgar use to access your datacenter.
You wouldn't loose any money with us; since all your transactions requires a login and password that we must buy every year; weather or not we use your software or not.

He replied a single sentence full of syntax and orthographs errors that sounded like you can only get the description of the house the agent wrote (which is about 1% of what we need) in a acces format. I guess he was talking about Microsoft access.

He didn't talked about how; but I figured it out soon enough by making a .mdb search I found exactly one access file that I wasn't able to use because it was password protected.
I then used a password cracker to crack the password; and finaly I was able to extract data that looked like the results from the last search I made

So; in order to integrate this datasource with the software I'll have to :
Make a macro that automaticaly do searches (It won't be easy; it's a GUI based system)
Use ODBC to pump the data from ms access to database backend (postgresql)

I would have been so simpler if they provided me a .dll or a documentation of the protocol they use; and like I said they won't loose any money since to access the data; we need a password.

Why do they absolutely don't want us to access their data directly ???

Like said in the topics;
We're in 2005
Web services have been around for a while already
Technologies are more and more opens
Please, do not ask people to pay 2k $ per years for a service they can't access the way they want.

Empty checkboxes aren't in $_POST

2005-07-21T16:13:00.000-04:00

I just took 4 hours to debug an algorithm; and the root cause of the bug was this :

This algorithm was based on something like for each value posted in the http transaction (foreach in $_POST)
do stuffs

However; some stuffs wasn't done when dealing with empty checkboxes;

After a while; I finally realised that empty checkboxes aren't defined in $_POST;

A good thing to know ;)

Day 4

2005-07-20T20:15:00.000-04:00

Ok today I want this thing working before dinner

We completely dropped the xslt api and relied on the xsltproc command; ok it's a hack; but no time to waste

Recode; well the whole use of the recode lib was a hack; we rewrote using proper header( ) commands to set the encoding; and configured postgresql to throws out stuffs in the correct encoding

Ok it works :)

Now the only things to do are to adapt the software with his specific need and adapt it with his old MS Acess system..

Day 3

2005-07-20T20:05:00.000-04:00

Ok; today we begin to port the application from php4 to php5

Encountering a few issues :

- xslt processor : the API completely changed; trying to port the the new api but I encounter a lot of issues; think about modifying the design to drop the use of the xslt api
- recode api : I can't make php compile with the recode extension; dropping it (wasn't a really important module anyway)
- postgresql : everything works fine; no api change

After a whole day porting I get no big results;

Let's see what tomorrow brings

Day 2

2005-07-20T19:55:00.000-04:00

Ok today I finished setting up the server; I created a few zones;

again this box is awesome; creating a solaris zone usually takes around 10-15 minutes; I was able to create a zone in less than 5 minutes !

However; I encountered a few networking issues; When I setup a server in a zone; I can't seem to access it from the other zones. Beside; nmapping the other zones from the root zone reports all ports as filtered...

Therefore I just gave up; putted everything in the root zone; and everything's nice by now;
Compiled php5 for apache2 : 2 minutes !

Had a strange issue with php5; doing svcadm disable http; svcadm enable http didn't seem to restart apache2; I had to do :
svcadm disable http
pkill httpd
svcadm enable http

After that everything worked fine
Enought for today; tomorrow begin porting the app from php4 to the new php5 environnement

Day 1

2005-07-20T19:52:00.000-04:00

I've been working on a software for a realestate evaluator company for the last few months; and now it's time to start deploy and finish developpement there.

Today I've setted up the server :
Tyan s2882-D motherboard with 2x 2gHz opterons cpu
2x73gb 10k rpm drives
4 gigs of ram

Did a fresh install of solaris 10; even if the install was ** slow; everything seems to be ok; damn this box is fast !

AMD tour

2005-06-12T15:21:00.000-04:00

last monday I've been in Toronto for the AMD Tech tour. It was a really great experience! First we entered; it was in a nice Hilton Hotel with a lot of high-class people... They gave us badges with our name and company on it, they showed us a couple of really interesting demonstration on how x64 and dual core is great, here are some example :

You have a big dataset (9gb). A software does some computation in the dataset.
Xeon : 18 hours
Opteron with 64 bit OS : 5 minutes

... wow !

How can a 10 minutes hardware change can double your speed ? (this was maybe the most impressing one)
You have a software that does rendering. The current setup is 2x opterons. The rendering software split the image in 2 parts so it's optimised for 2 cpus.
In 10 minutes, you shut the box down, changes the cpu to double-core cpus, reboot (no config changes required)
You restart the rendering application, the image splits in 4 so it's optimised for 4 cores, and it's 4x faster.

I only have a word : wow; thoses technology rocks !

I also bought a nice system while I was there. It's a dual opteron system based on a tyan s2882-d motherboard with 2xopteron 246-c (2gHz opterons that supports PC4000 ddr) .. all for 500$

I've met a lot of nice people there, it was a really nice conference !

Since them I try to complete the system; I've bought a antec titan 550 as a case (the cheaper EATX case I've found.. this mb is uge !) with a 550W powersupply, 2 8cm fans for the psu and a large 12 cm fan for the case.

The only thing missing before I can boot it is ram... ECC 400mHz 2x512mb ddr dimm aren't always available at the local shop...

The case have bright blue leds with USB, audio and firewire posrts in the front, wow ! Not mentionning there are thumbscrews everywhere, for the side pannel and the front panel (required to remove to access drives)

This will be an awesome system !!

The only thing I regret is the absence of any graphics bus (agp/pci-e)... that is sad... However the tyan guys told me a regular pci card would work nicely and would probably works faster than on a regular system because of the pci-x bux... I didn't tried it but I'll take his word...

This will really be a killer box..

I'm debian linux !

2005-06-09T01:28:00.000-04:00

Which OS are You?

P2P, privacy and the solution to this mess

2005-05-21T20:15:00.000-04:00

You certainly can't ignore the fact that thoses days, P2P is a very controversal topic and that a lot of people are getting sued by the RIAA because of P2P'ing

A first solution would be making this system semi-private;

you make a discharge that goes like this :
This is a private network; unless you have the written permission of the user to connect to his computer, you are not allowed to do so.
If you are a member of any anti-p2p organisation such as but not limited to : ..... you aren't allowed to use the network.

But in fact everyone can download the software and nobody cares about who connects to his computer. HOWEVER, since it's a private network and since you haven't given your authorisation to the RIAA to access your files, they can't sue you unless they have a search warrant from a judge. And I guess judges have other things to do then give warrant to the RIAA every days...

The other part of this solution is to encrypt the data using a public key scheme, this way they can't snoop your data and realise you're downloading music.

I hope thoses solutions will make some noise and a P2P network like this will start someday....

Darth Vader's blog !?

2005-05-21T15:44:00.000-04:00

I've hit this blog today :

http://darthside.blogspot.com/
btw yes, he uses the same template as I do...

It's a really curious blog... go read it

Java experiment

2005-05-21T15:31:00.000-04:00

This week I've played a bit with Java. It's a really interesting technology !!
For my first real application I've build a multithreaded server application with a really interesting design:

At startup, start min_thread workers (I choose to start 10)
Create a queue of sockets that corresponds to the connection queue; the clients that waits;
Open the socket and wait for connection
Make each threads wait on the queue until it's notified
When someone connects, push the socket on the queue and notify() a thread
the thread will work while you can come back to work (listen to socket)

It's really interesting on how powerfull is the multithreading model in Java !

The whole app takes about 100 lines of codes.
There is no exploitable buffer overflow
This app is quite secure

Wow !

Toughts on differential equations

2005-05-21T15:13:00.000-04:00

Differential equations are the most difficult problem created by the human kind, it's far in front of trying to understand the other kind (man trying to understand girls / girls trying to understand boys) which is another really difficult problem.

Did you know that's because of our incapacity to solve differential equations that we can't predict the atmosphere's behavior accuratly ?

Most differential equations behave in a really strange way; a small precision chance in the initial data will change the whole result; this is called the butterfly effect (Lorenz)

Last week, I was trying to solve a problem with differential equations in it; and even maple couldn't solve it :(
But I succeeded ! so I'm better than maple 8 !! unfortunatly a friend told me maple 9 could solve this problem so... I'm not that smart I guess; but still.. this was a really difficult problem.

There are different way to solve differential equations; if you are lucky and get one with sperable variables like :
xdx + ydy = 0 you can just do
/ /
| |
| f(x) dx + | g(y) dy = 0
| |
/ /

and the rest of the problem sits on your ability to solve integrals; however if you get stuffs such as non separable variables (linear differential equatio, or quadratic, etc); then things get really hard to solve;
For a linear equation, for example dy/dx + 2y/x = 7x^4; you just have to multiply everywhere by 1/dx to get :
dy + 2ydx/x = 7x^4/dx
Then there is a little trick we call the integrator factor in french.. I don't know the exact translation; that is multiply everywhere by e^(Int(term of the middle...)) in this example :

/ / | | |
| | 2/x dx|
| | |
\/ /
e
That is x² in this example;
So you multiply everywhere, you get x²dy + dxydy = 7x^4dx and then WOW you realise the left side of the equation = d(x²y) !!!
so you get
Int(d(x²y) = Int(7x^4)dx
which easily solve as y=7x³/5 +C/x²

From now on things get wild, for a quadratic equation you have multiple linearly independant solutions (I've talked about it in a earlier article) but can still solve them easily;

From 5th order and on, it's really hard to solve the problem. Fortunatly, with most problem ends up with 2nd order or less differential equations (because of Newton's law that only define 2 order of differentials; da/dt=v; dv/dt=x; )

Have fun solve differential equations !!

Hyper-Threading Harmfull

2005-05-14T16:27:00.000-04:00

I've read this article today :

Hyperthreading Considered Harmful

It's really interesting, and note that article don't talk about AMD dual core system or sun sparc ultra IV (dual core); but really and only about P4 hyperthreading

mmmm

Fixed

2005-05-14T16:26:00.000-04:00

I fixed the bug, putting quote everywhere solved the problem...

It's still a strange issue.

MYSQL performance problem/bug

2005-05-03T20:57:00.000-04:00

I have a table mysql that have 250k rows of 10 fields each (tbl_rights) and another table that have 2 rows (tbl_rapports).

I run this query :
SELECT * FROM tbl_rapports INNER JOIN tbl_rights ON tbl_rapports.fld_rapport_key = tbl_rights.fld_ressource_key AND tbl_rights.fld_ressource_type = 6 WHERE fld_dossier_key=1 AND (tbl_rights.fld_uid = '' OR fld_rights_world_read=1 );

result :
2 rows in set (2.58 sec)

mmmm 2.58s for 2 rows... ok this box don't have fast i/o, but the tables were all in ram... I mean, this isn't a box built for db but a desktop but it should definitaly be faster than this.

I ran the same query on a sun ultra 2 with 2 processors or 300mHz (ultrasparc processors with big caches), 512 mb ram with a RAID array that could produce quite 13MB/S but again the table that had only 68mb was ALL IN RAM.

result : 16 seconds.

Ok well.. thoses are only 300mHz processors.. let's put the blame on this... even tough I know some people who use sun ultra 2 for productivity quite happily with other database systems such as postgres.

Now let's make a real test -- The same query with the same database on a Sun Enterprise E4000 with 4x400mHz cpu and 4gb ram.
16 seconds again.

The table had index everywhere it needed, here is the output of EXPLAIN .... :

+----+-------------+--------------+------+-----------------------------------------------------+------+-
| id | select_type | table | type | possible_keys | key | key_len | ref | rows | Extra |
+----+-------------+--------------+------+-----------------------------------------------------+------+-
| 1 | SIMPLE | tbl_rapports | ALL | PRIMARY,index_fld_rapport_key,index_fld_dossier_key | NULL | NULL | NULL | 2 | Using where |
| 1 | SIMPLE | tbl_rights | ALL | index_fld_ressource_key | NULL | NULL | NULL | 217154 | Range checked for each record (index map: 0x2) |
+----+-------------+--------------+------+-----------------------------------------------------+------+---

look that everything is indexed...

Another thing... Since a benchmarks lot of comes to the conclusion that mysql is faster than postgres, oracle, db2 I only have one comment, they didn't tried INNER JOINs on their benchmark

The 3 tests were maid with a UGE mysql config

If anyone have a comment on how I could increase performance of mysql are welcome to do so, but so far I'm not really impressed.

A Unix-ready laser printer at a winprinter price

2005-05-03T20:40:00.000-04:00

Today I've bough a laser printer from futureshop, an electronic store in canada. It's a laser printer from samsung, nothing really amazing,, The really amazing thing is that on the box was written :

Compatible with windows 98, XP, etc etc
AND
Linux Debian Red Hat Caladera TurboLinux

mmmm nice they took care of linux.

I come home, plug the printer, insert the CD.

I first experienced a little bug with the installation script; the first line of the script was
#! /bin/sh

and not
#!/bin/sh

like it should have been, and to correct this bug I ran bash ./setup.sh instead of just ./setup.sh

Wow, a nice java GUI setup starts, and if X wasn't available a CLI interface would have popup but since I was on my desktop, it started the GUI interface.
I had choice to install either CUPS or a LP extension.. I choose CUPS; the installator installed cups and popped up a nice configuration utility, I choosed the model of my printer in the list, and BANG ! it worked !
I printed a test page, working.
I printed a graphic from maple, it worked.

Wow, 2 minutes and Ihad my printer working.

I read the script setup.sh to see how it was dealing with other architectures or if only x86 was supported. Well to my surprise, it supports (without explicitly telling on the box :)

Solaris
IRIX
Linux/PPC
Linux/x86 - it don't have a build of linux/x64
HPPA
SCO

WOW, amazing. I never had good experiences with setting up a printer in linux ( I always had thoses winprinters sh** ) but this one is really amazing !! 2 minutes with a GUI setup and everything was done.

The model of the printer is SAMSUNG ML-1740; it's really amazing how it works so fine. I bought it 129$ which is 30$ more expensive than the toner for it.
It didn't came with a full toner, the toner is filled at 1/3

I'm still surprised within 2 minutes I could print.

20 years too late

2005-04-19T22:19:00.000-04:00

While reading this blog from a Microsoft Employee , I realised some people are really 10 years too late

While wonder what will the 64 bits world looks like why it's ALREADY THERE SINCE THE HELL OF A LONG TIME

Sun, SGI, Nintendo are 3 companies among thoses implementing a 64 bits solution wasn't a choice; they had to make it because 64 bits was a need. Now thoses folks wonders what will the 64 bits world will look like

While Sun thinks about implementing 128 bits processors since they may needs it in about 10 years
While Unix implemented administrator/unpriviledged user structure since 1970 (unpriviledged user by default exept for root)
While even nintendo needed 64 bits for their Nintendo (implementing a 64 bits mips processor from sgi)
While a lot of current researches at many different layers of our scientific community are limited by 64 bits and would need 1024 bits if it was available

Microsoft folks still wonders what will the 64 bits world looks like, and brags that longhorn will have unpriviledged users by default, an entire community only have one word : sorry your juste 10 years too late (for 64 bits) and 35 years too late for unpriviledged account by default

What sucks with easy distro

2005-03-31T16:03:00.000-05:00

I'm confronted to a really unpleasent problem. As I've written in my previous blog entry, I use ubuntu on my ppc because it's the distro that is the most well supported. However, I have a nfs issue since last week and I can't find support anywhere. I could find support for every single issue about dri acceleration, alsa, xv, xmms, kde, gnome, but NOBODY can help me about NFS because most people that use this distro don't even know what it is or that they have exactly 1 computer and don't care about on of the most important thing in our world : networking. I've posted an issue on their forum, I ask help on their irc chanel but I can't get help to get NFS working.
I don't know it looks like portmapper and rpc are only listening to 127.0.0.1 ..

This is what sucks with easy and good looking distro like ubuntu; you can get every features you don't really need working, but the important one like the nfs server don't work

What Rocks with XML

2005-03-31T15:57:00.000-05:00

Here is what really rock with XML

You can use your xml file to both use in application and as a documentation;
for example, I use xml to create, describe and manage database. The application I've created automatically manage a database as the xml file tell it to. However, I can also use the same xml with a small xslt file to transform it into a nice html repport with the documentation on all the tables (the key, the links beetween tables, the indexes), all in one shot. Really nice !

That is what rock with XML, not only you can reuse the same file accross multple programs and mulptiple platform, you can also reuse it for multiple purpose !

Installing linux on a iMac

2005-03-28T20:41:00.000-05:00

I recently got a nice iMac from my job, it came with yellowdog linux, and a forgotten root password. Since I don't have OS X I didn't have choice but to stay with linux.

I first grabbed yellowdog 4 since it's the OS that came with that box (I tought it would be a good idea)... hell it wasn't a good idea.

First you need to fetch 4 CD from the internet, then you go through a endless list of useless question and have some weird default settings like "use network authentification by default", and stuffs like that.

I tought since yellowdog is a distribution built especially for apple's boxes, the hardware support would be good !
I was.. wrong

The system didn't supported the ati 128 bit that on this (this isn't a recent card... really) and couldn't support more than 800x600 with the fbdev interface.. and worse, with 256 colors.
It didn't supported sound.
It didn't supported keyboard keys such as eject and volume regulation.

I was hell disapointed.

Since I'm an all-time debian lover, I decided to grab debian for ppc.

The installtion was quite nice. I couldn't get X, sound and keyboard keys to work, but at least I had apt-get !!

I tried to install a 2.6 kernel to get alsa working but.. I couldn't it to boot back. It was now dead.
The topic of #debianppc was right "Debian on ppc : think of it as a never-ending IQ test"

I gave a try to another linux distro : ubuntu linux

This is the best move I done.

While this distribution is somewhat still incomplete (some packets are non-installable because of missing deps, etc) it's a really nice distribution for the ppc.

It almost worked out of the box ! On the first boot I got alsa and dri and xv, and APT !!
There was a bug in gnome that leaved me unable to use X however...

then I wanted to login as root, but realised the installer didn't asked me the root password.... believe it or not, the root account is disabled by default !! you have to do sudo if you want to do root commands !!
I did sudo passwd and enabled it

Also, since I don't use DHCP, I couldn't get network to work (the installer didn't asked me about how I wanted to configure my network).
I edited /etc/network/interfaces, configured the network to use static IP, created /etc/resolv.conf because it wasn't existing, edited /etc/apt/sources.list, added deb sources, apt-get update; apt-get upgrade

Here we go, it worked nicely

and now gnome works

The verdict is, while ubuntu is definiatly not a production server's distribution, it's a really nice distribution for a desktop since it was supporting all hardware out of the box

also....

2005-03-14T18:16:00.000-05:00

Given that
i^2 = -1
ln(-1) = ln(i^2) = 2lni
ln(i) = pi*i/2

combine that with the last blog entry, and you can get the logarithm of any number in C, positive or negative.

ln of negative numbers

2005-03-14T17:58:00.000-05:00

Continuing the Pi, mysterious number, blog entry...

I came to a completely useless conclusion, that pi = -i*ln(-1), and couldn't express ln(-1) in terms of other variables than pi.
However, I tough about another use for this... if we just take

axiome 1 : ln(-1) = i*pi
axiome 2 : (-1) = (-1)^(2k+1) where k E N

Then, start with

ln(-x) where x>0 (E R)
ln(-x) = ln(-1*x) = ln(-1) + lnx
ln(-x) = ln( (-1)^(2k+1) ) + lnx
ln(-x) = (2k+1)ln(-1) + lnx
ln(-x) = (2k+1)(i*pi) + lnx

That's it... and we come to the weird conclusion that there is an infinity of linearly dependant solutions

I should sleep sometimes....

Maple String Concatenation tricks for loop programming

2005-03-12T10:05:00.000-05:00

I found a really usefull tricks :

if you have many equation that have the same name style (for example eq1, eq2, eq3, eq4)
or in this cases, sums of forces in x : F1x, F2x, etc...
and want to do the same operation on every equations

>for i to 6 do
> F||i||x:=simplify(F||i||x/cos(omega*t));
> end do;

the || operator act as a string concatenator.. that have for result to execute the line for every i.. really usefull

Open windows

2005-03-12T08:26:00.000-05:00

Bugs come through open windows... keep windows shuts !

We are surrounded by illusions

2005-03-12T08:10:00.000-05:00

Think about it....

When looking around you, you never really see reality.. you see what used to be the reality some time ago, but you never really see it....

That means we all live in the past...

Einstein rocks

I'm currently reading an astronomy book from Huber Reeves, a montreal's astrophysicist, and he talk about it in a such way :

When we look really far in the universe, we can see where we come from

That means that maybe someday the astrophysicis will find the point where there is only a big amount of plasma (the starting point of the universe)

And also.. about pulsars... if they are all so far, we can wonder... do they exists anymore ?

Unix Admin Corner

2005-03-12T08:09:00.000-05:00

This is a very good blog about unix, solaris, linux, etc
Click on a few ad while you're at it ;)

Pi, misterious number

2005-03-12T07:58:00.000-05:00

This morning, when waking up, I tought about how we could express the number Pi in function of other constants

Starting with my last blog entry :
e^(i*pi) = cos(pi) + isin(pi) = -1 if you remember trigonometry

ln[e^(i*pi)] = ln(-1)
i*pi = ln(-1)
pi = ln(-1)/i = -i*ln(-1)

Here we go ! Next time you have to use pi write -i*ln(-1) to confuse everyone around and looks more intelligent than them

And when they'll tell you ln(-1) don't exists insult them because it does exists,
ln(-1) = i*pi
so we get back to :
-i*(i*pi) = pi because -i²=1

mac-laurin series, absolute values, e, cos, sin

2005-03-11T23:28:00.000-05:00

Last week during a math class I unconsciously re-discovered euler notation for complex numbers...

Starting from the mac-laurin (or taylor with a=0) serie of e^x
sum(x^(2i+i)/(2i+1)! ) = 1+x+x²/2!+x³/3! + x^4/4! + ...

comparing it to sine series :
sum((-1)^i*x^(2i+i)/(2i+1)! ) = x - x³/3! + x^5/5! + ...

and cosine series :
sum((-1)^i*x^(2i)/(2i)! ) = 1 - x²/2! + x^4/4!

and figuring out that
| sum((-1)^i*x^(2i+i)/(2i+1)! ) | + |sum((-1)^i*x^(2i)/(2i)! )| = sum(x^(2i+i)/(2i+1)! )

that really putted me on a track...

then I tough... how can I remove thoses abs( )... then comes complex numbers...
if we say x = ia, and put this in the series of e^x,
we get : e^(ia) = cosa + isina
amazing !

Integrals met Vector Spaces...

2005-03-11T23:22:00.000-05:00

I never tought someday I would mix vector spaces (a purely abstract math concept) and differential equations... for example; let's say we have the fallowing equation :

d²y/dx² + y = 0

We have two "main" solutions:

y = Asinx
y = Bcosx

and each of their combinaisons :
y = Asinx + Bcosx

thinking about it, I realised this solution was a vector space of second order
it's base is sinx and cosx
each of thoses vectors are perpendicular to each other
and every combinaison of thoses two vector is included in the vector space
y = Asinx + Bcosx

so the solution to a differential equation is a vector space... amazing isn't it ?

Transforming a Windows box into a Posix compliant box with SFU

2005-03-11T22:08:00.000-05:00

I've recently installed Windows Software for Unix (sfu) on my windows box...

SFU is from far the best move M$ made during the last few years... not only it includes some GNU software, but it transform your non-portable windows OS into a posix compliant windows OS

This is the path I took to get the nfs client/server for windows working :

Download SFU
Install it with option NFS server and NFS authentification server. disable gateway for nfs and enable password syncronisation
copy /etc/passwd and /etc/groups to the windows pc
if you have samba working and shadow password on the nfs server, you could also share a copy of it or share it read-only. this would enshure syncronisation
reboot the windows computer (maybe it's posix but it still need a reboot)
in administration tools, go in sfu, user name mapping, select passwd and group file, then enter the path to thoses files
apply
Click on Maps on the top bar
check advanced map
fetch windows/unix users and associate each others
save, go in network neighborhood, select NFS networks

here you go you can now use the nfs client to connects to other UNIX computers and share with them (next blog maybe)

I believe in web applications

2005-03-11T21:59:00.000-05:00

Web Based Apps are the futur

I really believe that from now on, every application should have their interface "web-based". There is no reason why people wouldn't do it that way.

html/xml is simpler than X or Windows API
html/xml is portable
java is portable
With https, ssl, 2048 bit encryption, ssh tunnels, ip filtering and firewalls, there is no reason to say that web-based design is insecure
Also, you can limit the size of the input your program recieve by modifying the input html tags, buffer overflow caused by too big user input are now past
By opening a web browser, you can have access to your application, wherever you are on the network

Also, you get back the client/server concept and "network is the computer" make all it's sense.

I believe in web based designed applications

Jonathan's blog

2005-03-11T21:49:00.000-05:00

I found a really interesting blogger : Jonathan Schwartz (from sun microsystem) actually build up a blog :
http://blogs.sun.com/jonathan

It's really nice that we can really see the human behind this so influent person

Really quick DNS Howto

2005-03-11T21:34:00.000-05:00

How to setup a DNS Server with BIND and debian in 2 minutes (tested with debian sarge)

Install bind : apt-get install bind9
Update the root zone : dig @e.root-servers.net . ns > /etc/bind/db.root
Take care of /etc/bind/named.conf.local by adding something like this :

zone "local" {
notify no;
type master;
file "/etc/bind/local.hosts";
};
Create /etc/bind/local.hosts (my example file):

$TTL 3D
@ IN SOA enterprise.local. root.enterprise.local. (
199802151 ; serial, todays date + todays serial #
8H ; refresh, seconds
2H ; retry, seconds
4W ; expire, seconds
1D ) ; minimum, seconds
;
NS enterprise ; Inet Address of name server
MX 10 sparc.local. ; Primary Mail Exchanger
MX 20 enterprise.local. ; Secondary Mail Exchanger
;
localhost A 127.0.0.1
enterprise A 192.168.0.101
sparc A 192.168.0.100
Note that bind DON'T LIKE EMPTY LINES. Each blank lines should start with a ; (a comment) so bind isn't confused.
Read more about the SOA Records here : http://www.zytrax.com/books/dns/ch8/soa.html
Restart Bind : /etc/init.d/bind9 restart

Here we go... it should work...

If not :

This is a VERY GOOD ressource, read it more than once http://www.tldp.org/HOWTO/DNS-HOWTO.html

http://dnsworld.no-ip.com/ have some good ressources about DNS and stuffs
#dns on freenode is a DNS help chanel where I usually hangs up. This channel is quiet so be patient...

Also... don't forget to put your server in /etc/resolv.conf or you won't use your brand new dns server ;)

MS Access Sucks

2005-03-11T21:29:00.000-05:00

Hey, can you realise people still use MS Access for their applications ? I met someone who had a 2gb access database and wondered why it crashed...

Think about it... 2gb of access databases... splitted into 4 files...

And it's not like access had an once of portability.. everything is written in Visual Basic.

The idiots are taking over....

PHP Rocks

2005-03-11T21:07:00.000-05:00

Each time I write php I'm amazed by the power this simple and easy scripting langage have. PHP is really like an iceberg. You only see the little tip at the top an never really can fully estimate what it can give to you.
I first got into PHP because it would allow me to make dynamic web pages, and because I was tired to copy/paste template to all of my files because I didn't knew about xml and xsl.
Then I discovered the power of mysql
Then I discovered it could read/write with an interface that is as powerfull as C, but much more simpler and secure... (Anybody here ever encountered a PHP buffer overflow ????)

Now I use php for all most of my applications that don't require i/o or really tight loops or complex algorithm. I think it's a good thing since it allows me to do everything in a web-based setting, which I think is the future. Not only accessible from everywhere around the world (if you have a public server), but also, you don't need to have direct access to your monster (your app server) to see the result, or even to setup X forwarding.
Not only html is simpler than X programming, it's also more secure, and faster too

And if you really need security than there is https

Well, PHP rocks

A ss4 crash....

2005-03-11T20:58:00.000-05:00

Last month I went through a really strange issue...

My Sun SparcStation 4, with solaris 8, apache 2, php 5 and mysql 4 crashed...

It was really sad since it was the first crash I ever encountered with a sun box... and it was a real crash ! Solaris just shutted down and I got back to that OBP ok prompt, and got to "boot" again.
I finally got over it and decided to put less load on this box my shutting down the mysql 4 server running on it.

The day after, it crashed back to OBP.. again !
I booted again and investigated about the possibility of a hardware failure. The POST indicated some defective RAM so I began looking to buy some new ram.

However, while reading about the Sun enterprise E3500 I heard that when a Windows PC shuts down or reboot, it sends a BREAK signal to every serial port connected to it.

After some investigation, I found that I forgot to disconnect the serial cable from ss4 to the pc I use as a console (that is used by other people), and when this PC was rebooting, the ss4 was crashing... That solved the issue.

I just want to tell you to unplug the serial cable from a unix server once you finished with it... Just plug it when you need it and don't be lazy like me

Student Strike

2005-03-11T20:53:00.000-05:00

In Quebec we are currently encountring a really sad issue... The [enter word here] prime minister Jean Charest wants to cut 103 million dollars in education, in the scholarship program. This is a really sad issue and will probably only cause the rich to get richer and the poor to get poorer.
To fight back against this, the students in every cegep ( about 20 000 students) decided to make a strike until the prime minister give the 103M back to us.

Let's see how it will go for the next weeks....

First Post

2005-03-11T20:29:00.000-05:00

Hi all ! My name is Eric Boutin, I'm a programmer/unix system admin living near montreal, quebec. Welcome to my life