How to change memory and other JVM settings for STS

[MiB]

Hey!
I don't know the exact details about how to calculate the exact maximum possible memory settings for a JVM, but according to this:
http://www.oracle.com/technetwork/ja...#gc_heap_32bit
it seems at least reasonable to get something between 1.4GB and 1.6GB when running a 32bit JVM.
HTH,
Martin

I also found an interesting discussion at stackoverflow: Maximum Java heap size of a 32-bit JVM on a 64-bit OS which makes some comparisons to 32bit on 64bit systems. It's just too bad Apple never made a 64bit JVM for the G5.

Anyway, it seems that on 32bit Mac OS X the maximum heap space is about 1590 MiB, making my 1516m as close as I can wish. However, for some reason certain lower values won't instantiate STS.

Is "1516m" about 1516 MiB or is it something else in this context?

I also checked the used resources of STS in Activity Monitor which states that about 588 MB is in use with about 2.5GB of virtual memory (150MB private virtual memory).

Anyone can suggest the best source for practical JVM knowledge?

[janwen]

What about my 4G memory on win7 64bit os

Here is what I am using quite successfully on my 8GB OSX machine:

-vmargs
-Dosgi.requiredJavaVersion=1.5
-Xmn128m
-Xss1m
-XX:+AggressiveOpts
-XX:+UseConcMarkSweepGC
-XX:PermSize=64M
-XX:MaxPermSize=712M
-XX:+HeapDumpOnOutOfMemoryError
-XX:CompileThreshold=200
-XX:+UseCompressedOops
-Xverify:none
-XX:+UseBiasedLocking
-XX:+UseFastAccessorMethods
-Xms768m 
-Xmx1280m
-XstartOnFirstThread
-Dorg.eclipse.swt.internal.carbon.smallFonts

[Martin Lippert]

Hi!

If you run a 64bit JDK and a 64bit STS, you can use an even higher max heap limit, if you want (-Xmx2048m, for example), but I would take care of not using too high settings for the max heap to avoid virtual memory swapping on your machine (slows down everything).

HTH,
Martin

[janwen]

thanks Martin,I user 64bit jdk and 64bit STS On my 64bit win7,I just set 256m ,but my laptop become very slowly ,so i want to get some optimization here

[Martin Lippert]

You can enable the heap monitor in STS to see what the current heap size is that STS is using (Preferences -> General), but I would recommend to use something around 1024m as -Xmx in your case.

HTH,
Martin

[janwen]

-XX:+UseParallelGC
-server
Above parameters can affect the tomcat or other jsp container speed?
I am not familiar with above parameters

[Martin Lippert]

Hi!

Just as a side note: If you set JVM settings in sts.ini, they are not affecting your Tomcat or tc Server. Those settings (and this thread) are for the JVM that run your IDE (Eclipse/STS).

And I have no personal data to share what the best settings for tc Server or Tomcat are. You should ask those questions in the Tomcat and/or tc Server forums. I guess there are a lot more people more familiar with settings for Tomcat and tc Server.

Regarding STS: I would not use -server (this switches the internal JVM incremental compiler technology to the server-side variant, giving you better performance when you have long-running processes), but if you have multiple cores, I would use -XX:+UseParallelGC (which improves garbage collection speed due to parallel execution within the GC)

HTH,
Martin

[janwen]

thanks,Martin, I'll try some new resolution for my case,and then share my experience here.

[janwen]

Sorry,I spent two days on transforming my myeclipse projects to STS,but failure,I google and google again,I give up STS.

[Martin Lippert]

Hey!

Can you let us know what exactly the problem is?

Cheers,
-Martin