0 Replies Latest reply on Feb 24, 2013 12:19 PM by 992998

    G1GC said "heap expansion operation failed"

      Hi guys.

      I'm testing G1GC of jdk 1.7.0_13 now.

      However VM said "heap expansion operation failed" in gc log.

      10632.453: [G1Ergonomics (Heap Sizing) attempt heap expansion, reason: humongous allocation request failed, allocation request: 16793616 bytes]
      10632.453: [G1Ergonomics (Heap Sizing) expand the heap, requested expansion amount: 17825792 bytes, attempted expansion amount: 17825792 bytes]
      10632.453: [G1Ergonomics (Heap Sizing) did not expand the heap, reason: heap expansion operation failed]

      Those message have appeared not only once, but also often appeared.

      1)Why is VM memory allocation failed?
      2)To use G1GC is, do I need more heap?
      3)How to avoid this problem without increase memory?

      CentOS release 6.2 (Final) 64bit
      jdk 1.7.0_13
      Tomcat 7.0.35

      VM opstions
      -server -Djava.awt.headless=true -Xms3g -Xmx3g -XX:+UseG1GC -XX:MaxGCPauseMillis=200
      for logging gc
      -Xloggc:$CATALINA_HOME/logs/gc.log -XX:+PrintGC -XX:+PrintGCDetails -XX:+PrintGCTimeStamps -XX:+PrintGCDateStamps -XX:+PrintAdaptiveSizePolicy -XX:+PrintFlagsFinal