Top Reporting High RES & SIZE for JVM Process (Doc ID 985184.1)

Last updated on AUGUST 04, 2016

Applies to:

Oracle Coherence - Version: 3.1.0 to 3.5.2 - Release: to AS10g
Oracle Containers for J2EE - Version: 10.1.3.0.0 to 10.1.3.5.0   [Release: AS10gR3 to AS10gR3]
Enterprise Manager Grid Control - Version: 10.2.0.5 to 10.2.0.5   [Release: 10.2 to 10.2]
Information in this document applies to any platform.
***Checked for relevance on 27-Sep-2011***

Symptoms

JVM's showing very high RES and SIZE even though they are specifying a maximum heap size of 1024M. The JVM sometimes would suddenly consume significant amount of memory. When this happens, the operating system starts to get noticeably slower, and eventually starts to terminate other low priority processes.

For example, normally, from 'top' output, the JVM consumes ~3G virtual mem, and ~500M res mem as below.


PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND

27400 root 25 0 2969m 452m 38m S 0.0 45.2 5:03.36 java.sgm

However, when this problem occurs, the JVM memory utilization would suddenly increase significantly. From 'top' command, you observed the JVM is using 7.2G virtual memory and 3.5G res memory.

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND

13925 root 19 0 7206m 3.5g 5808 S 2 90.4 6:13.79 java.sgm

Furthermore, at the time when this problem occurred, the Java API "java.lang.Runtime.totalMemory()" and "java.lang.Runtime.freeMemory()" reported used memory is less than 500M as it should be.

Cause

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