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ISSUE: java.lang.OutOfMemoryError: Java heap space Message: Java heap space

Article ID: 5321
Reviewed: 20/03/2018

Product Version:
AhsayACB / AhsayOBM: or above
OS: All platforms

Problem Description

When performing a backup of any type, the following error message is received in the backup report:

No. Type Timestamp Log
* ... ... ...
* info ... Start running post-commands
* ... ... ...
* erro YYYY/MM/DD hh:mm:ss [BackupIpcThread.doRunException] error: java.lang.OutOfMemoryError: Java heap space
Message: Java heap space
* ... ... ...


The message suggests that the AhsayOBM / ACB client application had ran out of memory during the backup process.


To resolve the issue, perform the following steps:

  1. Confirm on the amount of free memory available on the client computer prior to a backup.

  2. Increase the Java heap size setting according to the free memory available and memory usage during a backup on the client computer.

    The instructions can be found by Clicking Here.

    Important Note:
    Please note that there is no concrete recommendation for the Java heap size setting, because that will depend greatly on the client computer's setup, size of backup (in terms of number of files and files' size), and the user's backup behavior.  As a rule of thumb when adjusting the Java heap size setting:

    • Do not set the heap size to a value larger than 60% of the actual RAM (physical memory) available on the client computer.

    • Increase Xmx (maximum heap size) in small increments (e.g. 512 MB at a time), until you no longer experience the java.lang.OutOfMemoryError error.

      This is because increasing the heap beyond the capabilities of the client computer to adequately Garbage Collect (GC) can cause other problems (e.g. performance issue / freezing).

      Do not blindly set the heap size to a ridiculously large value.

    • Consider setting Xms (initial heap size) and Xmx (maximum heap size) to the same value, to minimize Garbage Collections (GC) and to prevent wasting JVM resources used to constantly grow and shrink the heap.


OutOfMemoryError, java, heap, space, memory, crash

public/5321_java_heap_space.txt · Last modified: 2018/03/20 16:32 by edward.chan