javamemorygarbage-collectionheap-memoryjstat

How to read the output of "jstat -gcutil <PID>?"

I am running a JBoss server and following output belong to -gcutil tool. I am curious what is this abbreviations.

/usr/java/jdk1.7.0_25/bin/jstat  -gcutil 47929 
  S0     S1     E      O      P     YGC     YGCT    FGC    FGCT     GCT   
  0.00   0.00  68.46 100.00  57.08  44539 5829.704 303497 241552.104 247381.808

Thanks

Solution

  • S0 = Survivor space 0 utilization as a percentage of the space's current capacity.

    S1 = Survivor space 1 utilization as a percentage of the space's current capacity.

    E = Eden space utilization as a percentage of the space's current capacity.

    O = Old space utilization as a percentage of the space's current capacity.

    P = Permanent space utilization as a percentage of the space's current capacity.

    YGC = Number of young generation GC events.

    YGCT = Young generation garbage collection time.

    FGC = Number of full GC events.

    FGCT = Full garbage collection time.

    GCT = Total garbage collection time.

    Refer the documentation at https://docs.oracle.com/javase/7/docs/technotes/tools/share/jstat.html#gcutil_option

    Additionally you can refer http://www.cs.lafayette.edu/docs/java/tooldocs/share/jstat.html also.