When I'm trying to compile a strategy, sometimes I see only Compiling message without Compilation Successful. In Java Console I found this error:

04.02.2012 09:35:32.421 SEVERE a.c ] Uncaught exception in [common-1-thread-6] thread: Java heap space
java.lang.OutOfMemoryError: Java heap space
at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)
at com.sun.crypto.provider.SunJCE_f.b(DashoA13*..)
at com.sun.crypto.provider.AESCipher.engineDoFinal(DashoA13*..)
at javax.crypto.Cipher.doFinal(DashoA13*..)
at com.dukascopy.dds2.greed.agent.a.a.a(Unknown Source)
at com.dukascopy.dds2.greed.agent.a.f$c.write(Unknown Source)
at com.dukascopy.dds2.greed.agent.a.f.u(Unknown Source)
at com.dukascopy.dds2.greed.agent.a.e.a(Unknown Source)
at com.dukascopy.dds2.greed.util.e.e(Unknown Source)
at com.dukascopy.dds2.greed.actions.CompileAndRunAction.uB(Unknown Source)
at com.dukascopy.dds2.greed.actions.c.run(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
at java.lang.Thread.run(Thread.java:680)

Usually when this happens, I'm not able to compile any strategy until JForex Client restart, then it is OK.

Tested on MacOS X 10.7.2, Java 1.6.0_29.

Finally I found a small hack to prevent this, max heap size is set to 512MB, I increased it to 2GB in jnlp file:

<java version="1.6+" initial-heap-size="32m" max-heap-size="2048m"/>

Maybe it would be good to set it to at least 1GB by default.

It is not normal to have such used heap size. Have you checked if you have any memory leaks of any of your strategies? You can check it by attaching jvisualvm profiler to the hava application and then monitoring the heap size.

I guess there is some memory leek in JForex client. In my code, I include most of strategy code using @Library directive with jar file that I build in Netbeans, and I accidentally added to this jar file one 137MB file, so final file was relatively big, and memory usage became bigger after every build/run (typically more than 1GB) and even clicking Collect button to call garbage collector didn't help much, probably some pieces from older builds are still referenced, and so not cleaned. I see this also now, when using smaller jar files (1-2MB), that memory usage is slowly increasing after every build.