Support Article

VBD not starting when DDS configured with external Cassandra



Visual Business Director (VBD) is unable to start when Decision Data Stores (DDS) is configured with external Cassandra.
This is due to VBD's check that ensures at least one DDS is in the NORMAL state before starting. However, DDS is reporting to be in state CLIENT when configured with external Cassandra.

Note that if you configure DDS with Internal Cassandra, and then switch it to External, then it reports to be in state NORMAL and VBD can start. It is only when you start clean and configure DDS with External Cassandra that we have the issue.

Error Messages


2016-07-11 16:39:55,108 [ef5.cached.thread-15] [ STANDARD] [ ] [ ] (rvice.operation.StartOperation) INFO - Starting service [VBD.Default] 
2016-07-11 16:39:56,500 [ef5.cached.thread-15] [ STANDARD] [ ] [ ] ( node.impl.PRPCVBDManagement) ERROR - VBD was unable to start. 
com.pega.decision.vbd.node.PersistenceUnavailableException: Unable to start VBD when there are no DNodes 
at com.pega.decision.vbd.node.VBDBootstrap.bootstrap( 
at com.pega.decision.vbd.node.impl.PRPCVBDManagement.start( 
at com.pega.decision.vbd.node.VBDDSMService$1.execute(

Steps to Reproduce

  1. Enable DDS service with external Cassandra. 
  2. Start the system. 

VBD does not start and an ERROR is reported. 

Root Cause

A defect in Pegasystems’ code or rules.
DDS state validation is failing when VBD starts, causing VBD to abort. This occurs when DDS is configured to point to external Cassandra.


Apply HFix-28599.


Published July 29, 2016 - Updated August 4, 2016

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