TB124 Validated Sync for SQL Server AG dSources May Stop Working on Upgrade to 25.0.0.0

Impact

Validated Sync for SQL Server Availability Group dSources may stop working after upgrading to 25.0.0.0 in certain scenarios, such as missing permissions or unreachable/undiscovered replicas. 

Contributing Factors

• Missing VIEW ANY DEFINITION and VIEW SERVER STATE permissions for the Environment User on the undiscovered replicas. 

• Complex availability group configurations such as the following:

  • Windows Server Failover Cluster (WSFC) nodes hosted on Disaster Recovery (DR) network. AG replicas are unreachable due to restrictions from the DR network. 

  • If availability group replica(s) are present on Failover clustered instance(s) configured on Windows Server Failover Cluster (WSFC) nodes.

This article applies to the following versions of the Delphix engine:

Cause

A mismatch between the actual replicas present in the source environment and the replicas discovered by Delphix can cause sudden faults in Validated Sync for Availability Group (AG) dSources after upgrading to version 25.0.0.0. Delphix may be unable to discover certain AG replicas due to missing permissions or intentional restrictions, such as limited access to a Disaster Recovery node. 

Symptoms

Validated Sync for the AG dSource may raise the following fault, indicating a mismatch between the discovered replicas and the actual replicas present on the source: 

Fault: 

Validated sync for dSource "Delphix_dSource" failed with the error: Availability group replicas discovered for AG "Delphix_AG" on the source cluster environment "AG_Cluster" have become stale. A new set of AG replicas are available.  

Pending Action: Review the error. Additional recommendation(s): Refresh the source cluster environment "AG_Cluster" to discover the latest AG replicas. 

Relief/Workaround

• If the missing permission(s) is the only contributing factor for AG replica(s) mismatch, Validated Sync fault can be avoided by granting the Environment User VIEW ANY DEFINITION and VIEW SERVER STATE permissions on all AG nodal instances. Afterward, performing an environment refresh operation will allow the Delphix Engine to discover these replicas and ensure that Validated Sync functions without mismatch faults.  

• You may also choose to switch to “Delphix Managed Backup” and configure SnapSync policy. 

• Instead of Validated Sync, you can use the manual SnapSync.