PSC clean-up task failed due to Single Sign-On (SSO) Ring Topology replication

Products

• VMware vCenter Server

Issue/Introduction

Upgrade Reconciliation Drift fails during PSC clean-up with the following error:

domainmanager.log
yyyy-mm-ddThh:mm:ss.zzzz [ERROR Decorator.py::__call__call__::86::62565] Error occured during script execution
 Migration encountered an error
 MigrationErrorCode. PSC_CLEANUP_ERROR: Unable to perform PSC Cleanup: PostValidatePscDecommissionAction: Fetched topology with <node_count> nodes, contains nodes with invalid partner count, invalid node: [vc_fqdn(<partner_count>), vc_fqdn(<partner_count>)]
 Remediation: Refer config drift app logs for the error and retry after fixing the issue. 
 Original Exception: None
 ReferenceToken: <ID>
 Traceback (most recent call last):
   File "/apps/migrationcoordinator/packages/migration_coordinator/engine/decorators/Decorator.py", line 79, in __call_ 
    execute_result = self.func (self.instance_, *args, **kwargs)
   File "/apps/migrationcoordinator/packages/migration_coordinator/scripts/vc/PscCleanup.py", line 114, in execute
    raise mig_ex 
   File "/apps/migrationcoordinator/packages/migration_coordinator/scripts/vc/PscCleanup.py", line 110, in execute
    trigger_psc_decommission_from_config_drift ()
   File "/apps/migrationcoordinator/packages/migration_coordinator/scripts/vc/PscCleanup.py", line 46, in trigger_psc_decommission_from_config_drift:
    raise MigrationException (MigrationErrorCode. PSC_CLEANUP_ERROR, [failure_message], [])
 migration_coordinator.engine.exception.MigrationException.MigrationException: Migration encountered an Error

Environment

VMware Cloud Foundation 4.5.x

Cause

This is caused from a misconfiguration in the SSO Ring Topology where the replication node count is invalid.

By default in a correct SSO Ring Topology each node is expected to have 2 replication agreements within the SSO domain forming a ring between all nodes.

Resolution

To resolve the issue use the vdcrepadmin utility to determine and fix the misconfiguration in the SSO Ring Topology.

 

WARNING

Before making linked mode changes ensure that proper snapshots of the SSO domain or file-based backups of each vCenter via the VAMI have been taken.
Refer to KB VMware vCenter in Enhanced Linked Mode pre-changes snapshot (online or offline) best practice for further instructions. Failure to perform these steps can lead to replication problems across the VC databases. 

 
The commands to be used are: 

showpartners - Displays the current partnerships from a single PSC within a vSphere domain.

createagreement - Allows for creation of additional replication agreements between PSCs within a vSphere domain.

removeagreement - Allows for removal of additional replication agreements between PSCs within a vSphere domain.

Additional Information

Determining replication agreements and status with the Platform Services Controller (PSC)