Wednesday, February 28, 2007

Maven ftp:sitedeploy (HOWTO)

I published this article in June 2006 on internal company blog. I decided to re-publish it on my public blog because this way it could help wider audience.

Maven site:ftpdeploy goal does not work as expected?

Maven site plugin is used to generate and deploy a complete web site for project. There is a goal site:deploy (or site:ftpdeploy if you like) for this purpose but you can be disgusted by the fact that it may not work correctly when using maven 1.0.2.

Recently, I have been facing to this trouble and here is the workaround which works for me.

The root cause of this issue is quite well described in maven JIRA. In short Maven 1.0.2 is using ANT 1.5.3-1, which depends on NetComponents.jar. NetComponents.jar does not come with regular Maven distribution so you have to download it and pack into Maven configuration manually. The following mail thread discusses how to do it in detail.

In basic all you have to do is just copy NetComponents.jar into ${maven.home}/lib/ folder and modify ${maven.home}/bin/forehead.conf (add NetComponents.jar reference into [root] portion). This should make the site:ftpdeploy goal work as expected.

Interestingly, this issue should be fixed in Maven 1.1, unfortunately, as of writing it hasen't been officially released yet (RC1 is available). Developers are now more focused on M2 (Maven 2) which will probably introduce a lot of other headaches... :-)

If you are using site:ftpdeploy goal in you code then every member of your group should be familiar with this workaround and make modification of maven configuration on his/her local computer.

Monday, February 19, 2007

Interesting Study About Hard Disk Failure Trends

Several Google engineers performed analysis of hard disk failure trends of their storage infrastructure running inexpensive commercially available hard drives with interesting results. The study itself [2] is a nice reading for statisticians. For more popular (light) version see a BBC article [1]. If I were to highlight the result in one short sentence then I would pick the following one:


We found very little correlation between failure rates and either elevated temperature or activity levels.

Putting aside the results what impressed me is that they had to collect high volume of quality and well structured data from a distributed real time system. Their system (System Health Infrastructure) is briefly described in [2]. It is mostly built on top of Google own technologies (MapReduce, Bigtable, GFS) which allow for a large data set to be effectively stored. Final statistical analysis is done by R system.



References:
[1] Hard disk test 'surprises' Google (BBC news)
[2] http://labs.google.com/papers/disk_failures.pdf

Tuesday, February 6, 2007

Manila Flashback


Manila
Originally uploaded by Lukáš Vlček.
I was ordering photos from Manila trip and found this one. It was taken during the last day from hotel window (image was digitally post-processed). View from Alabang to Manila center.

Pineapple Ball

Recently, I bought a new brain-teaser called Pineapple Ball. It is wooden rebus made of 33 different pices. I solved it after couple of days and I found that it is more about dexternity then brain power. Sometimes two hands are not enough, may be that is why they say it is an intellective game.