I have been working on a large java application. It is quite parallel, and uses several fixedThreadPools (each with 8 threads). I am running it on a computer with 2 cores, each with 4 processors. My program is analyzing large sets of data, and the analysis is saved (serialized) after every set, though it works across data sets, and so is re-loaded every time I run a new one (and then saved). My problem is this: after running 4-5 data sets (takes about 2 days, and I'm pretty happy with my coding efficiency) it will crash, after exactly the same amount of time on the 5th set (no matter which data set I use). The program is repetitive, and so there is nothing new in the code going on at this time. It is reproducible, and I am not sure what to do. I can post the full error log if that would help... I understand that this problem is ambiguous without a lot more detailed information, but if there are any go-to suggestions, it would be greatly appreciated.
I have been testing different settings to see if anything helps, and right now I am running with the following arguments.
-Xmx6g -Xmx12g -XX:+UnlockExperimentalVMOptions -XX:+UseG1GC
Thanks, Joe
#
# A fatal error has been detected by the Java Runtime Environment:
#
# SIGSEGV (0xb) at pc=0x0000000000000000, pid=18454, tid=140120548144896
#
# JRE version: 7.0_03-b147
# Java VM: OpenJDK 64-Bit Server VM (22.0-b10 mixed mode linux-amd64 compressed oops)
# Derivative: IcedTea7 2.1.1pre
# Distribution: Ubuntu precise (development branch), package 7~u3-2.1.1~pre1-1ubuntu2
# Problematic frame:
# C 0x0000000000000000
#
# Failed to write core dump. Core dumps have been disabled. To enable core dumping, try "ulimit -c unlimited" before starting Java again
#
# If you would like to submit a bug report, please include
# instructions on how to reproduce the bug and visit:
# https://bugs.launchpad.net/ubuntu/+source/openjdk-7/
#
I'd instrument it with something like Visual VM. It'll show what's happening in memory, threads, CPU, objects created, etc. in real time as your app runs.
The nice version that I have is for Oracle/Sun JVMs only. There's one that ships with the JDK, but I don't believe it shows as much detail as the version 1.6.3 with all plugins installed.