82:173 Could not connect to the CVD on remote host to launch the DeDuplication Database engine process for Store Id [...].

82:173 Could not connect to the CVD on remote host to launch the DeDuplication Database engine process for Store Id [...].

Symptoms

Data Protection Operations fail with error 82:173 and the logs indicate issues connecting to CVD on the remote host.

iDA Logs:

15488 4c68  11/03 17:59:21 2332215 CSignatureQuery::ConnectSIDB() - [ERROR] Failed to contact the SIDB engine [22]. Error [Could not connect to the CVD on remote host to spawn the SIDB engine.] 15488 4c68  11/03 17:59:21 2332215 CSignatureQuery::QuerySignaturesAsync() - [ERROR] Connect SIDB faild (53002)

Causes

The error indicates a network connection between the client and the Deduplication Database.  If any required port is not open, then the client cannot connect to the DDB.

Resolution

To resolve this issue:

• Ensure the base Required Ports are open.
• Use Check Readiness on the Client and Media Agent(s).
  • There's a great article on our community about troubleshooting readiness failures here
• Confirm overall network connection and stability between the client and Media Agent.