Processes do not trigger. DB Connection messages in bg-ca.log

Products

• Clarity PPM On Premise
• Clarity PPM SaaS

Issue/Introduction

Our process engine was showing 'Status unknown' in one of the servers and processes were not triggered during that time. 

On checking the bg-ca.logs we see the below error. 

ERROR 2020-11-12 08:26:37,754 [Post Condition Transition Pipeline 0 (tenant=clarity)] bpm.engine (clarity:process_admin:43518712__13E550D2-FAB2-4576-BD2D-441E049F5093:none) Error in pipeline
com.niku.bpm.BpmException: Cannot get DB Connection
 at com.niku.bpm.engine.persistence.BpmContext.getContext(BpmContext.java:137)
 at com.niku.bpm.engine.persistence.BpmContext.getContext(BpmContext.java:109)
 at com.niku.bpm.engine.persistence.BpmContext.getContext(BpmContext.java:97)
 at com.niku.bpm.engine.rules.Pipeline.run(Pipeline.java:279)
Caused by: java.sql.SQLException: Connection unavailable
 at com.niku.union.persistence.connection.ApacheContext.getConnection(ApacheContext.java:213)
 at com.niku.union.persistence.connection.ApacheContext.getConnection(ApacheContext.java:204)
 at com.niku.bpm.engine.persistence.BpmContext.getContext(BpmContext.java:132)

Environment

Release :  15.8.1

Component : CLARITY ENVIRONMENTAL

Resolution

For root cause, check with your Clarity DBA to check for issues that occurred on the database at the time as the log file indicates that there was a database connection issue.

Workaround: Restart the BG service