Advanced configuration

Last modified: 18 June 2020

Besides the standard options available, MPS enables you to perform low-level configuration of the underlying platform and the Java runtime.

warning

This may lead to unexpected problems and make your MPS installation inoperable if you are not sure what you are doing. Contact JetBrains Support for instructions regarding the options and values that might help you with whatever issue you are trying to solve.

JVM options

MPS runs on the Java Virtual Machine (JVM), which has various options that control its performance. The default options used to run MPS are specified in the following file:

<IDE_HOME>\bin\mps64.exe.vmoptions (for the default 64-bit JVM)

<IDE_HOME>\bin\mps.exe.vmoptions (for the optional 32-bit JVM)

warning

Do not change JVM options in the default file, because it is replaced when MPS is updated. Moreover, in case of macOS, editing this file violates the application signature.

Configure JVM options

Do one of the following to create a copy of the default file with JVM options in the configuration directory that will override the original file:

  • On the Help menu, click Edit Custom VM Options.

  • If you do not have any project open, on the Welcome screen, click Configure and then Edit Custom VM Options.

  • If you cannot start MPS, manually copy the default file with JVM options to the MPS configuration directory.

If you do not have write access to the MPS configuration directory, you can add the MPS_VM_OPTIONS environment variable to specify the location of the file with your preferred JVM options. This file will override both the original default file and the copy located in the MPS configuration directory.

note

If you are using the Toolbox App, it manages the installation and configuration directory and lets you configure JVM options for every IDE instance. Open the Toolbox App, click the screw nut icon for the necessary instance, and select Settings.

Common options

The default values of the JVM options should be optimal in most cases. The following are the most commonly modified ones:

Option

Description

-Xmx

Limits the maximum memory heap size that the JVM can allocate for running MPS. Default value depends on the platform. If you are experiencing slowdowns, you may want to increase this value, for example, to set the value to 2048 megabytes, change this option to -Xmx2048m.

-Xms

Specifies the initial memory allocated by the JVM for running MPS. Default value depends on the platform. It is usually set to about half of the maximum allowed memory (-Xmx), for example, -Xms1024m.

-XX:NewRatio

Specifies the ratio between the size of the young and old generation of the heap. In most cases, a ratio between 2 and 4 is recommended. This will set the size of the young generation to be 1/2 to 1/4 of the old generation correspondingly, which is good when you are often working on one project and only a few files at a time. However, if you are constantly opening new files and switching between several projects, you may need to increase the young generation. In this case, try setting -XX:NewRatio=1, which will make the young generation as large as the old generation, allowing objects to remain in the young generation for longer.

For more information about available JVM options, see the java reference for Windows or macOS/Linux.

Platform properties

MPS enables you to customize various platform-specific properties, such as the path to user-installed plugins and the maximum supported file size. The default properties used to run MPS are specified in the following file:

<IDE_HOME>\bin\idea.properties

warning

Do not change platform properties in the default file, because it is replaced when MPS is updated. Moreover, in case of macOS, editing this file violates the application signature.

Configure platform properties:

Do one of the following to create an empty idea.properties file in the configuration directory that will override the values from the original file:

  • From the Help menu, select Edit Custom Properties.

  • If you do not have any project open, on the Welcome screen, click Configure and then select Edit Custom Properties.

  • If you cannot start MPS, manually create an empty idea.properties file in the MPS configuration directory.

If you do not have write access to the MPS configuration directory, you can add the MPS_PROPERTIES environment variable to specify the location of the idea.properties file. The properties in this file will override the corresponding properties in both the original default file and the one located in the MPS configuration directory.

Common properties

Users often change the following properties:

  • The default IDE directories may need to be moved, for example, if the user profile drive runs out of space or it is located on a slow disk, if the home directory is encrypted (slowing down the IDE) or located on a network drive, if you want to create a portable installation or exclude caches from home directory backups, and so on.

    Property

    Path to

    idea.config.pathConfiguration directory
    idea.system.pathSystem directory
    idea.plugins.pathPlugins directory
    idea.log.pathLogs directory

    Specify paths with forward slashes /, including Windows paths (for example, C:/idea/system).

    You can insert properties as variables. For example, use ${user.home} (standard Java system property) to specify paths relative to the user's home directory: 

    idea.config.path=${user.home}/MyIdeaConfiguration

  • Limits that can affect performance:

    Property

    Description

    idea.max.content.load.filesize

    Maximum size of files (in kilobytes) that MPS is able to open. Working with large files can affect editor performance and increase memory consumption. The default value is 20000.

    idea.max.intellisense.filesize

    Maximum size of files (in kilobytes) for which MPS provides coding assistance. Coding assistance for large files can affect editor performance and increase memory consumption. The default value is 2500.

    idea.cycle.buffer

    Maximum size of the console cyclic buffer (in kilobytes). If the console output size exceeds this value, the oldest lines are deleted. To disable the cyclic buffer, set idea.cycle.buffer.size=disabled.

    idea.max.vcs.loaded.size.kb

    Maximum size (in kilobytes) that MPS loads for showing past file contents when comparing changes. The default value is 20480.

MPS provides a number of other properties that define interaction with the environment (window managers, launchers, file system, and so on). Most of them act like hidden settings (in the sense that they are not evidently exposed), which you may need to enable or disable in certain cases. Change these properties only if advised by JetBrains Support.

Default IDE directories

By default, MPS stores user-specific files (configuration, caches, plugins, logs, and so on) in the user's home directory. However, you can change the location for storing those files, if necessary.

note

The default IDE directories changed starting from MPS 2020.1. If you had a previous version, new installations will import configuration from the old directories. For information about the location of the default directories in previous IDE versions, see the corresponding help version, for example: https://www.jetbrains.com/help/mps/2019.3/tuning-the-ide.html#default-dirs.

Configuration directory

The MPS configuration directory contains user-defined IDE settings, such as keymaps, color schemes, custom VM options, platform properties, and so on.

Syntax
%APPDATA%\JetBrains\<product><version>
Example
C:\Users\JohnS\AppData\Roaming\JetBrains\MPS2020.1

You can change the location of the MPS configuration directory using the idea.config.path property.

To share your personal IDE settings, copy the files from the configuration directory to the corresponding folders on another MPS installation. Make sure that MPS is not running to avoid erasing the copied files when you shut down the IDE. Depending on which settings you modified, the MPS configuration directory can contain the following subfolders:

Directory

User settings

codestyles Code style schemes
fileTemplates

User-defined file templates which pertain to the entire MPS workspace

filetypes

User-defined file types

keymaps

Customized keyboard shortcuts

options

Various options, for example, feature usage statistics and macros

shelf

Shelved changes

tip

If your settings are synchronized using the Settings Repository plugin, these subfolders are located under settingsRepository in the configuration directory.

If your settings are synchronized through the IDE Settings Sync plugin, these subfolders are located under jba_config in the configuration directory.

System directory

The MPS system directory contains caches and local history files.

Syntax
%LOCALAPPDATA%\JetBrains\<product><version>
Example
C:\Users\JohnS\AppData\Local\JetBrains\MPS2020.1

You can change the location of the MPS system directory using the idea.system.path property.

Plugins directory

The MPS plugins directory contains user-installed plugins.

Syntax
%APPDATA%\JetBrains\<product><version>\plugins
Example
C:\Users\JohnS\AppData\Roaming\JetBrains\MPS2020.1\plugins

You can change the location of the MPS plugins directory using the idea.plugins.path property.

Logs directory

The MPS logs directory contains product logs and thread dumps.

Syntax
%LOCALAPPDATA%\JetBrains\<product><version>\log
Example
C:\Users\JohnS\AppData\Local\JetBrains\MPS2020.1\log

You can change the location of the MPS logs directory using the idea.log.path property.