I believe there are free tools to do it, but even making your own tool is easy. JVMTI will help. Here is a simple JVMTI agent I made to trace all exceptions: #include <jni.h> #include <jvmti.h> #include <string.h> #include <stdio.h> void JNICALL ExceptionCallback(jvmtiEnv* jvmti, JNIEnv* env, jthread thread, jmethodID method, jlocation location, jobject exception, jmethodID … Read more
Windows: In your Tomcat /bin folder, you should have a tomcat5w.exe admin app (or in later versions tomcat6w.ex, tomcat8w.exe, etc). Go to the Java tab and add the args in the “Java Options:” box. Note that when you add new args, you need to add them as NEW LINES in that box (above or below … Read more
From what I can tell, the only thing that the 1.6 JVM does with CMSPermGenSweepingEnabled is to print that message – it’s not processed the way it is in 1.5. For CMSClassUnloadingEnabled to have any impact, UseConcMarkSweepGC must also be set.
If you want to use 32-bit references, your heap is limited to 32 GB. However, if you are willing to use 64-bit references, the size is likely to be limited by your OS, just as it is with 32-bit JVM. e.g. on Windows 32-bit this is 1.2 to 1.5 GB. Note: you will want your … Read more
Could it be that you’re using a 32-bit jvm on that machine?
The JVM will start with memory useage at the initial heap level. If the maxheap is higher, it will grow to the maxheap size as memory requirements exceed it’s current memory. So, -Xms512m -Xmx512m JVM starts with 512 M, never resizes. -Xms64m -Xmx512m JVM starts with 64M, grows (up to max ceiling of 512) if … Read more
The permanent space is where the classes, methods, internalized strings, and similar objects used by the VM are stored and never deallocated (hence the name). This Oracle article succinctly presents the working and parameterization of the HotSpot GC and advises you to augment this space if you load many classes (this is typically the case … Read more
Apparently, _JAVA_OPTIONS works on Linux, too: $ export _JAVA_OPTIONS=”-Xmx1g” $ java -jar jconsole.jar & Picked up _JAVA_OPTIONS: -Xmx1g
When you are using JVM in 32-bit mode, the maximum heap size that can be allocated is 1280 MB. So, if you want to go beyond that, you need to invoke JVM in 64-mode. You can use following: $ java -d64 -Xms512m -Xmx4g HelloWorld where, -d64: Will enable 64-bit JVM -Xms512m: Will set initial heap … Read more
If you used Aptitude (apt-get) to install Jenkins on Ubuntu 12.04, uncomment the JAVA_ARGS line in the top few lines of /etc/default/jenkins: # arguments to pass to java #JAVA_ARGS=”-Xmx256m” # <–default value JAVA_ARGS=”-Xmx2048m” #JAVA_ARGS=”-Djava.net.preferIPv4Stack=true” # make jenkins listen on IPv4 address