Change the boot Java runtime of the IDE

Last modified: 23 April 2021

As a Java application, MPS includes JetBrains Runtime (based on OpenJDK 11), which is used by default. It is recommended to run MPS using JetBrains Runtime, which fixes various known OpenJDK and Oracle JDK bugs, and provides better performance and stability. However, in some cases you may be required to use another Java runtime or a specific version of JetBrains Runtime.

note

Changing the runtime may cause unexpected problems. Do not change it unless you were specifically asked to do so by JetBrains support.

Switch the Java runtime used to run MPS

  1. From the main menu, select Help | Find Action or press Ctrl+Shift+A.

  2. Find and select the Choose Boot Java Runtime for the IDE action.

  3. Select the desired runtime and click OK.

    If necessary, you can change the location where MPS will download the selected runtime.

  4. Wait for MPS to restart with the new runtime.

When you open the Choose Boot Runtime for the IDE dialog for the first time, it may take a while to load the list of JetBrains Runtime builds from the server.

To use a different Java runtime available on your computer, select Add Custom Runtime under Advanced. MPS lists all the JDKs and JREs that it was able to detect. Alternatively, click Add JDK to specify the location of the desired Java home directory.

To reset back to the default runtime that the IDE initially used, click Use Default Runtime.

The path to the selected runtime is stored in the mps.jdk or mps64.jdk file in the MPS configuration directory. If there are problems with the selected runtime, you can delete this file to revert to the default runtime.

You can also override the runtime used for MPS by adding the MPS_JDK environment variable with the path to the desired JDK home directory.