KB-1226 Content (collaboration) engine consumes high memory


The Content (Collaboration) engine's database process occupies high memory on RAM when compared to the size of the .kdb file on disk. The general rule of thumb is that the KDB files should consume roughly 2.5 times the amount of RAM as they do disk space, in gigabytes.


This issue is usually observed when you have a large number of versions of a single constant, which increases the memory footprint of the Content engine's database process.

This issue can also occur when using the "Update Constant Smart Service", which creates new versions of a constant every time it's run. This creates a lot of versions of a constant over time.


  1. Download and install the latest version of Content Tools.
  2. Import 5314.Rule_Constant Version Analysis.zip into your environment. This app was built in Appian 7.8 and will work in Appian 7.8 and later.
  3. Run the Analyze Rule and Constant Versions action in the Rule/Constant Version Analysis application.
    1. Under Constant or Rule, select Both.
    2. Under Minimum Number of Versions, select 100. Appian Technical Support may request this number to be lower depending on how many objects there are.
    3. Hit Submit.
  4. Analyze the CSV file provided at the end of the action. Export, delete, and re-import all objects in the list.
  5. Restart Appian to reclaim memory.

In most situations, Appian Technical Support recommends updating the design to avoid using constants and moving/writing the value to a database instead.

Affected Versions

This article applies to all versions of Appian.

Last Reviewed: January 2020