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Command Line Tools

Oak Run

This tool supports maintenance operations such as backup and compaction.

Some of the documentation of this tool is found at and some at and some at


We recommend to use the same version of oak-run as the one of oak-core deployed on your system.


To back up a repository, use:

java -mx4g -jar oak-run-*.jar backup <repository> <backup>

When using the (default) Tar storage, the <repository> setting is the path to the directory that contains the segment (data*.tar) files. The <backup> option is the target directory.


To list the checkpoints of a repository, use:

java -mx4g -jar oak-run-*.jar checkpoints <repository>

When using the (default) Tar storage, the <repository> setting is the path to the directory that contains the segment (data*.tar) files.


The oak-run compact operation may be used to perform an offline compaction:

java -mx4g -jar oak-run-*.jar compact <repository>

It makes sense to find and remove the old checkpoints, using the checkpoints command described above.

Index Management

The oak-run index operation is used to manage indexes.

System properties supported by the oak-run

When performing operations on the SegmentNodeStore (eg. backup, checkpoints, compact), it’s possible to tweak various system properties to get the optimal performance. These are:

  • cache - cache size for the SegmentNodeStore (default: 256),
  • compaction-progress-log - how many entries should be compacted between log messages (default: 150000),
  • update.limit - threshold for the flush of a temporary transaction to disk (default: 10000),
  • tar.memoryMapped - allow to use memory mapped files to reduce memory usage (default: false),


java -Dtar.memoryMapped=true -mx4g -jar oak-run-*.jar checkpoints <repository>

Analyzing Thread Dumps

To analyze thread dumps, filter out idle threads, and get profiling data, use the following, there the directory contains thread dump files:

java -jar oak-run-*.jar threaddump --filter --profile <directory>

MongoDB Shell with oak-mongo.js

MongoDB comes with a command line shell that can be extended with custom JavaScript. Oak provides a oak-mongo.js file with MongoMK specific extensions. You first need to download the JavaScript file and then start the MongoDB shell with the file.

mongo --shell oak-mongo.js

Now the MongoDB shell has an oak namespace with additional functions.