Jenkins and multiple CPU-Cores

[Manuel Doninger]

Hello,
i'm currently running a build, which is very CPU-consuming. The CPU
load of the Java process for Jenkins is at 25%. It is running on a
Windows 2003 Server (32 bit) with 4 CPU cores with a JDK 6. However, i
thought, that Windows 2003 and Java 6 would support multiple CPU cores
and distribute the load to all cores. Where is the limitation here,
and should that limitation gone, when we switch to Win 2008 64-bit
next week?

Manuel

[Didier Durand]

Hi,

The issues is most probably not in Jenkins nor in Java or OS but in
your build job: if its components Compiler, etc.) are single-threaded
and each comes after the other in regular suite then it will always
last this long.

What you have to do it re-design your build job in many smaller jobs
who can run in parallel: 1 does Findbugs checking, while the other
does compilation while does other junit tests, etc.

Of course, you have to define conditions in Jenkins when needed: junit
runs only after compilation if successful, etc.

If you have all this small jobs defined then they will all start in
parallel when you commit and then you will take advantage of your
multi-core cpu.

Then, you have to have enough executors defined in Jenkins global
parameters

When all this is done properly, your build may become much much
faster!

Good luck

didier