Howdy, >A tomcat process died on our production dumping a core file of size 1Gb. >The reasons are not known as what caused the same. We have specified the >following setting for the JVM: > >256K (min size) >778K (max size)
Are you sure that's K? Assuming you really mean M, how did you arrive at a number like 778? Maybe you mean 768? >I would like to know, what happens when the JVM reaches the max heap size? If the JVM cannot allocate any more system memory to heap because -Xmx is reaches, it will try full garbage collections frequently. If those don't reclaim much/any memory, ie the heap is full and referenced, you will get java.lang.OutOfMemoryErrors. You'll be able to see them in logs/catalina.out. However, the JVM won't crash for a long long time even while these are occurring. It'll thrash at a high CPU usage, and you will start getting random NullPointerExceptions throughout your code because referenced variables might be swapped out. But it won't crash with a core dump as you're describing. >Does it continue to run, I mean is there a point after which it cannot >sustain any longer as it has no space allocated to do so ? When does it >dump the core file, after encountering the some signal Internal crashes, not OufOfMemoryErrors, cause core dumps. >I would also like to know if anyone in the list havent restarted their >tomcats for months and are running their application smoothly (more >importantly the JVM is kept alive for months). Yes: we have numerous applications that have been running for more months now, including one that's been running tomcat 4.1.24 since it came out without stopping ;) >It would also help if anyone can point to some useful resource which >exaclty point to this problem / question. Moreover, anything else one >should look for apart from code leaks in this case to sustain the Jvm for >longer duration ? Yeah: core dumps frequently indicate a mismatch between the JVM and the OS. Look for missing OS patches or an upgraded JVM. Beyond that, I don't use tomcat 3.x nor an Apache front-end so I can't offer much specific help there. Yoav Shapira This e-mail, including any attachments, is a confidential business communication, and may contain information that is confidential, proprietary and/or privileged. This e-mail is intended only for the individual(s) to whom it is addressed, and may not be saved, copied, printed, disclosed or used by anyone else. If you are not the(an) intended recipient, please immediately delete this e-mail from your computer system and notify the sender. Thank you. --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
