Kris Buytaert's blog

Oct 28 2008

Virtualizing MySQL , are you stupid ?

or timebound ? or don't you have any load on your DB at all ?

I personally don't see many reasons to virtualize your database, apart from the , we plan to start small and scale out, or the we need it now and we don't have the hardware yet , putting your database on a virtual platform where you have to share resources with other virtual machines doesn't really sound like a tempting proposition to me. Small, almost idle databases , maybe. But enterprise production level databases no thnx.

Sheeri Cabral also mentions the above reasons .. and there also .. Enterprise Production use isn't listed.

Databases typically require a good amount of memory , and steady disk access.
So if you are in a production environment with a fairly loaded database, would you want a 4Gb machine with full direct memory access, Or 3.5Gb of virtual memory that can be ballooned to 3 if underused. My pick is at the 4Gb real memory.

The original article at Sun argues the use of Virtual Harddisk to move around workloads between different servers or even Virtualization platforms. But it fails to describe the guaranteed performance penalty of not using raw disks but a filesystem on top of a loopback device. How many layers do you want before actually write to the disks. Good practice in a virtual environment is to dedicate full disks or LVM parts to the virtual machine hence lowering the overhead, but most (default) setups do the opposite.

And don't get me started about the myth of using virtualization for high-availability :)

Now can somebody please remove all the clueless marketing people from planetmysql.org , thnx. (they can be identified with by a blogs.sun.com source and posts that mainly talk about Sun products including only a slight hint to MySQL)

(PS. What's a Market Development Engineer's job description anyhow ? , that's just a different name for Marketing Assistant right ?)

Oct 27 2008

TikiTag on Linux

After the O'Reilly GMT interview , the nice folks over at Tikitag sent me a Tikitag presskit to play with. I actually got it about 2 weeks ago but I only got like 5 minutes of time with it earlier. Just time to find the Linux Client and get that to connect to their site. So far so good ... I however couldn't get a connection between my reader and the client. The readers' led was constantly on.

So today I connected the reader to my Fedora based Dell Laptop, I figured out the content of the Debian package and copied those files (a startupscript and a jar file to my laptop)

The led started flashing gently. I restarted pcscd , started the client and the Java client detected the reader , I launched the Tikitag Dashboard but that failed to detect the reader till after I restarted my firefox.

From there on I could map tags to url's etc. So now I have a bunch of Tikitagged Businesscards.

So my next step is to figure out why it isn't working on my EEE. Because after all the EEE is what I carry around when going to conferences and other places .. which is when I might want to actually use the TikiTag reader. (Any ideas anyone ?)

There is a lot of potential for this kind of technology.. Imagine using it in a museum where you get a tagreader equipped device which you can use to read information about the artworks you are about to see.

Oct 27 2008

The Little 4 are back, John interviews Matt about openQRM,

I didn't even have time to finish my post about the Puppet Podcast and DevMinistration before John had already posted his chat with Matt as recorded yesterday in Eindhoven.

I'm glad I could bring these guys together ! Great stuff !

Oct 27 2008

DevMinistration

In his CloudCafe 18 Podcast John talks about Puppet to Luke and they coin the idea of Devministration

I really like the terminology, so I`m a devministrator, and probably the bigger part of Inuits are Devministrators.

The first stage in becoming a devministrator is using version control, then bugtracking .. etc.
Coming from an era where I was the sysadmin pushing the developers to use version control this sounds really strange to me..
Yes I had to convince developers to use version control, while Luke thinks he needs to convince sysadmins to use version control.
Weird.. other continent, other habits, but the important part is we all use it.

But the big part is that we don't spend our time managing servers, but rather scripting the automation of the management. Learning machines how they should manage our configs and automate.

Like the old Google saying, you have to automate yourself out of a job every 18 months.

Guess that's also what ad Devministrator is.

Oct 27 2008

CloudCamp BXL

Don't forget .. this thursday : CloudCamp Brussels !

Oct 27 2008

Geek Wear

So what happens when you run into a guy wearing a Barcamp ESM cap, an OpenNMS shirt and a Zenoss jacket. You ask him how he got all that stuff .

It seems to be pretty easy ..
Let see if it works for mee too :)

So Tarus and Mark , do you already have my snail mail address ? :)

Oh and Matt, we need some openQRM gear too :)

Oct 27 2008

T-Dose 2008 is over

It was fun, the good part about T-Dose is that is small enough to actually be able to speak with everybody you want to .. well almost .. there were still some people around I wanted to talk to but I didn't get the chance to . Specially Ber Kessels and Roy Scholten who filled in the gaps in the Drupal track. After my own talk I had to run to the other track so I could answer the tricky questions in our other talk about Open Source Monitoring Tools. And I never really made it back to the Drupal room. So Ber, Roy , next time you run into me I`ll buy you a Beer !

Anyway Pics are up (so Geert now finally has pictures of himself on stage)

Social event pic is also up ..

Slides (Drupal/ Virtualization) were already up

Somehow I had problems seeing al the sessions I wanted to see this year. lots of interesting things happening at the same time and therefore forcing me to choose for specific sessions. JP and Jeroen already announced they will be there again next year .. I just hope to have a better planned Drupal track then ...

T-Dose kind of concluded my current scheduled list of talks , I`m looking for new interesting conference venues to visit .. specially in southern Europe .. so if anybody has ideas :)

Oct 25 2008

Wholesale High Availability

Alan just coined WholeSale HA. The idea of rebooting a whole virtual machine rather than just failing over 1 service.

He wants to have the best of both worlds in 1 framework, he however doesn't specify what parts he likes from the WholeSale HA setup

Yes you want to use it coupled with hardware predictive failure analysis tools. In order to achieve Higher Availabilty, but I don't think the WholeSale HA part is real HA.

WholeSale HA isn't going to be fast enough for most of the business critical environments.
You simply cannot afford to reboot or even boot a full machine and the related downtime that brings for your service.

So yes a best effort combination, but with a strong focus on the application state would be preferred. WholeSale is a good start .. but it's definitely not where you want to stop.

Oct 25 2008

Linux.conf.au

Oct 23 2008

MythTV Broken again :(

The earlier posted fix , getting my data from mythportal seemed to be a temporary solution.

It also seems the solution that was mentioned at Kristof Vanhertum's blog , the agent fix doesn't work anymore either.

Somewhere in the comments of that post however people start referring to mc2xml a tool to get your info (even 14 days worth of it) from a really untrustworthy source and import it amongst other tools into MythTV

No source code to be found, just a binary .. something that always scares me .. But running the thing (first time as a dummy empty user, one never knows) actually seems to give me an XML file with relevant data , to be used by mythfilldatabase.

  1. ./mc2xml -c be -g 2610
  2. Loading ..... : mc2xml <mc2xml@gmail.com> (2008-09-15)
  3. Connecting .. : microsoft.com
  4.  
  5. Select lineup:
  6.  
  7. 0: TER Unmapped Analogue Terrestrial
  8. 1: TER Unmapped Digital Terrestrial
  9. 2: CAB Unmapped Analogue Cable
  10. 3: CAB Unmapped Digital Cable
  11. 4: SAT Unmapped Analogue Satellite
  12. 5: SAT Unmapped Digital Satellite
  13. 6: SAT TV Vlaanderen Digital Satellite
  14. 7: TER TV Vlaanderen Digital terrestrial
  15. 8: CAB Telenet Analog Kabel (132)
  16.  
  17. (0-8): 8
  18.  
  19. Downloading . : microsoft.com
  20. Downloaded .. : 353944 bytes
  21. Source ...... : BDS
  22. Headend ..... : 7200116
  23. Version ..... : 2693590756
  24. Start time .. : 2008-10-23T00:00:00 UTC
  25. End time .... : 2008-11-06T23:55:00 UTC
  26. Parsing ..... : Telenet Analog Kabel (132)
  27. Writing ..... : xmltv.xml
  28. Writing ..... : mc2xml.dat
  29. Completed ... : 5384193 bytes in 26s, 27 channels, 9409 programs scheduled.

Yes that's my actual postcode. Different postcode values will give you other alternatives such as Coditel/Integan .. so you better use the right one.

I`m not really satisfied however, it fails to recognize my already defined channels. So I seem to have something that at first sight looks like relevant data . Only my channel numbers are way way way off ..

I need to fix that asap. The only problem being that tomorrow it's Geekdinner and I`ll be spending the rest of the weekend at T-Dose hence I have no time to fix this anymore ...

Anyone got a quick fix for that ? Or will I just have to live with a weekend of non-recordings ? :)

Well.. maybe next week will be a productive one then :)