Solution

There could be multiple reasons causing the datastore to grow on its own. Perform the following tasks to reduce the size:

1. If you've configured the external datastore (for example, FileDataStore - ./repository/datastore), then try to run the Blob Garbage Collection from jmx console.
2. You can also monitor and check the cleaning of garbage by logger. Set DEBUG logger - org.apache.jackrabbit.oak.plugins.blob (fileDS.log). Once done, you can remove it. Also consider installing latest oak core-1.0.13 and recommended fixes.