KB-1895 Execution engines fail to start with "pe.kr: file not found" message in the db_PX* log file

Symptoms

Execution engine fails to start due to the following error printed in the service_manager.log file located in the <APPIAN_HOME>/logs directory:

ERROR com.appian.komodo.engine.EngineComponentService - execution01 failed to start with context RestartContext{mode=REPLICA, epoch=null, restart=true, attempt=3}
java.lang.RuntimeException: com.appian.komodo.engine.invoker.SignalReturnedException: Signal returned by engine: type
...
Caused by: com.appian.komodo.engine.invoker.SignalReturnedException: Signal returned by engine: type

The following error is printed in db_PX*.log file located in the <APPIAN_HOME>/logs directory:

[PX011] {pe1045.kdb ,0} () FATAL .a.db "pe.kr: file not found"

Cause

This issue is witnessed when the pe.kr file located in <APPIAN_HOME>/server/process/exec is missing. This file is utilized to build KDB files for the execution engines.

Action

Restore the pe.kr file from a backup or from another install on the exact Appian version.
Start the execution engines again as noted in the Start Script documentation.

Affected Versions

This article applies to Appian 17.3 and later.

Last Reviewed: March 2019