KB-1214 "FATAL .a.db "error loading kdb 'XXXX.kdb': wsfull"" error thrown in db_*.log when attempting to start Appian engines

Symptoms

When starting the Appian Engines, the following error can be observed in the db_*.log corresponding to an engine that failed to start:

FATAL .a.db "error loading kdb 'XXXX.kdb': wsfull"

Cause

There is insufficient memory to start the engine. An engine may be using more memory than normal if there are a large amount of transactions pending for that engine, which is often the case if the engine was not shut down correctly.

Action

Ensure there is sufficient free memory available, then attempt to restart the problematic engine. Generally, memory use for each engine may be up to 2.5 times the KDB file size on disk, and memory use will be higher if an engine has not been checkpointed for some time.

It may be necessary to start each engine individually using the start-gw.sh|bat script located in each <APPIAN HOME>/server/_scripts/<ENGINE NAME> directory.

To minimise the chance of this issue ocurring, ensure to always follow the documented shutdown procedure.

Affected Versions

This article applies to all versions of Appian.