IBM Support

Setting Maximum Heap Size for IBM Support Assistant Team Server 5 Heap Analysis Tools

Product Documentation


Heap dump analysis tools need a large amount of memory to analyze heap dumps that are very large and sometimes the default heap size isn't large enough. IBM Support Assistant Team Server 5 provides ways to set the maximum heap size for the various editions of its heap dump analysis tools.


Sometimes java.lang.OutOfMemoryError (OOM) exceptions occur when analyzing large heap dumps with the IBM Support Assistant Team Server 5 heap dump analysis tools. They include:

  • HeapAnalyzer [Desktop]
  • Memory Analyzer [Desktop]
  • Memory Analyzer [Report]
  • Memory Analyzer [Web]

Often the solution to OOM exceptions is to increase the maximum heap size for these tools. The methods for doing so are different for the various tool editions.

Report and Web tool configuration

Many problem determination tools available for IBM Support Assistant allow customization. These tools include properties files that you can edit to change the default behavior.

For example, follow these steps to increase the maximum heap size for Memory Analyzer [Report].

  1. Open a command window, shell, or file system browser on the system running IBM Support Assistant Team Server 5.
  2. Copy <install_dir>/ISA5/ToolBox/ to <install_dir>/ISA5/ToolBox/properties.
  3. Edit <install_dir>/ISA5/ToolBox/properties/ You will see a property named jvm.args.
  4. Increase the value of the -Xmx argument. For example, increase the default -Xmx2048M to -Xmx4096M and then save the file.
  5. If you changed property values for the Web edition of Memory Analyzer, then restart IBM Support Assistant Team Server to load the updated property values.

The next time you analyze a heap dump the new maximum heap size will be used.

See Tool Specific Configuration Options in the IBM Support Assistant 5 Knowledge Center for more information on configuring problem determination tools.

Desktop tool configuration

Beginning with IBM Support Assistant Team Server 5.0.1 you can customize the minimum and maximum heap sizes for desktop tools each time you launch them from the Tools tab. Follow these steps:

  1. Start a session with IBM Support Assistant Team Server.
  2. Click the Tools tab.
  3. Select a desktop tool from the list of tools.
  4. Click the "Launch" button above the tool details. A dialog opens with fields to set the minimum and maximum heap sizes.
  5. Set the minimum and maximum heap size values in MB.
  6. Click the "Launch" button on the dialog to start the tool.

Have questions or comments? You can post them to the IBM Support Assistant forum.

Have an idea for a new feature? You can open a Request for Enhancement.

Internal Use Only

These instructions for setting the heap size were removed on March 12, 2014 because the latest Java security enhancements don't allow modifying signed JNLP files. This is the text that was replaced:

Desktop tool configuration

IBM Support Assistant 5 uses Java Web Start technology to support desktop tools. Currently desktop tools do not use tool configuration properties files. To change the heap size for a desktop tool you must edit the JNLP file that downloads to your workstation. These instructions assume that Memory Analyzer [Desktop] is installed.

  1. Ensure that your browser is configured to ask you what to do when it opens JNLP files.
  2. Start a session with IBM Support Assistant 5.
  3. Click the Tools tab to open the list of installed tools.
  4. Click "Memory Analyzer [Desktop]" in the list of tools to open its details pane.
  5. Click the Launch button at the top of the details pane. A window will open with information about desktop tools.
  6. Click the Submit button on the information window. The browser will ask what to do with the JNLP file.
  7. Click Save to save the JNLP file to your workstation (e.g., memory_analyzer.jnlp).
  8. Open the JNLP file in an editor.
  9. Search for the <j2se> element for your workstation's OS.
  10. Add the max-heap-size attribute and set it to a value large enough for your environment.
  11. Save the JNLP file and type "javaws memory_analyzer.jnlp" to start Memory Analyzer [Desktop].

For example, set the maximum heap size to 2 GB on Windows.
<resources os="Windows">
<j2se version="1.6+" max-heap-size="2048M"/>

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Document Information

Modified date:
17 June 2018