We have a Windows 2003 R2 x64 virtual machine running as a guest under Oracle VirtualBox on 64-bit Linux. The Windows VM has 16GB of RAM and is running approximately 80 separate instances of tomcat. (These instances do a specific small function and do not require much power or cause much load.) With all services running, the server still has 3-4GB of free RAM. When we only had about 40-50 tomcat instances, everything was fine. But as we add more instances, we have a problem where tomcat services just spontaneously die. If we check the server after about 12 hours of uptime, we find that 5-6 services have stopped. A little later it might be 10-12 instances, and so on. It gets worse over time. There are no OOM errors in the logs, but attempting to restart the stopped services produces Windows error 1067, and the java logs contain the message "unable to allocate enough java heap space." By default, my Java instances are configured with -Xms128M -Xmx384M. Raising these numbers does not help, but if I lower them to, say 64MB, then Java will start and the services will come up (but then I have other problems with the application). All of this makes me think we have a problem with Java memory fragmentation because of having so many instances of Java, and the problem gets worse as the hours go by. Can someone recommend a way to diagnose and/or fix this problem? -- Eric Robinson Director of Information Technology Physician Select Management, LLC 775-885-2211 x 111
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