I have encountered below exception during execution of below command
jmap -dump:format=b,file=heap_dump.bin <process_id>
Dumping heap to <file_name>Exception in thread "main" java.io.IOException: Premature EOF
JDK version : 1.7.0_45
-Xms2g -Xmx4g -XX:+UseG1GC -XX:MaxGCPauseMillis=1500 -XX:G1HeapRegionSize=2 -XX:+PrintFlagsFinal -XX:ParallelGCThreads=4 -XX:ConcGCThreads=2
RHEL 5.x, 4 core CPU Linux machine 6 GB RAM
As per oracle bug report database ( http://bugs.java.com/bugdatabase/view_bug.do?bug_id=6882554), this issue has been fixed state but I am still getting jdk 1.7 version with build no:45
Can you suggest any solution other than upgrading to Jdk 1.8, which is not possible in my case due to other dependencies?
I have tried with below command and this command too does not work (generated partial dump file) and shows same Premature EOF.
jmap -J-d64 -dump:format=b,file=<filename> <pid>
I have triggered the command with the user, who started the process. That user had write permissions to the directory. The file was generated but it was incomplete.
9 MB file was written for
2 GB heap, which is not usable for analysis.
Brian's comment is helpful to resolve the issue.
If you are using
G1GC algorithm in 64 bit machine:
Below command does not work ( excluding
jmap -J-d64 -dump:format=b,file=<heap_dump_filename> <pid>
you have to use below option to get the heap dump
jmap -J-d64 -dump:live,format=b,file=<heap_dump_filename> <PID>
There are some suggestions to use
-F option to force heap dump but as per oracle technotes:
-F Force. Use with jmap -dump or jmap -histo option if the pid does not respond. The live suboption is not supported in this mode.
Since heap dump is required with G1GC option, above option can't be used.