Optimizing the Performance of the IDE

Working with a large number of files could affect the performance of Eclipse. There are some tasks and features that you can switch off, if they are not required, to minimize the impact on performance. You can also increase the memory allocation for Eclipse.

These are the areas to consider:


Working with a large code base could affect the performance of the editor. You can disable some of the IDE settings, especially the ones that are not in use, to help improve the performance.

For example, if you have large source files, you can switch off background parsing in the editor or use a larger Trigger delay - background parsing can generate a significant overhead, especially when dealing with a large code base. See Configuring Background Parsing for how to disable it.


To reduce the compilation time and the number of files in a project, ensure that the following project properties are disabled, if you do not need them:

  • On the Micro Focus > Project Settings > COBOL page in the project's properties:
    • Set Generate directives file to No.
    • Set Generate listing file to No.
    • Set Enable code coverage to No.
    • Set Enable profiler to No.
  • On the Micro Focus > Project Settings > COBOL > Code Analysis page in the project's properties:
    • Run active rule sets after build

See Building Applications in Eclipse for more details.

Disable the automatic directives determination

By default, Eclipse is configured to perform a Compiler directives scan of any files you add to your projects. The automated scanning could slow down the IDE when you have a very large source code base. If you do not want the IDE to perform a directives scan automatically, disable the feature as follows:

  • In Eclipse, click Window > Preferences > Micro Focus > COBOL > Directives Determination.
  • Uncheck Perform automatic directives determination.

You can use Determine Directives from the context menu on files to trigger the scan manually and only when needed.

Increase the heap size

To monitor how Eclipse is using memory, turn on the heap visualizer as follows:

  1. In Eclipse, click Window > Preferences > General.
  2. Enable Show heap status.

If you regularly receive out-of-memory exceptions in Eclipse or operations are slow, especially when working with a large code base, you can increase the amount of memory Eclipse can use as follows:

  1. Locate the eclipse.ini file in C:\Users\Public\Micro Focus\Visual COBOL\eclipse and open it in a text editor.
  2. Use the following options in the file to allocate more memory to Eclipse:
    --launcher.defaultAction openFile
    -Xmx1024m ( or -Xmx3000m)


Switch off any functionality that is not in use but can affect performance such as the WTP tools.