To recognize this symptom and provide a workaround to address it.
Symptoms:
2021-03-14T21:28:56.084Z INFO pool-310-thread-2 NSGroupMembershipUpdateTask - GROUPING [nsx@6876 comp="nsx-manager" level="INFO" subcomp="manager"] simpleExpressionNode [VirtualMachineContainer.name CONTAINS eng-paas-t-eusw1a-1-] mapped to NSGroups [NSGroup/9xxxxxx6-0000-0000-0000-exxxxxxxxxxe]
2021-03-14T21:27:11.418Z INFO NSGroupMembershipRefreshTask NSGroupMembersRefreshTask - GROUPING [nsx@6876 comp="nsx-manager" level="INFO" subcomp="manager"] current member count in NSGroup 9xxxxxx6-0000-0000-0000-exxxxxxxxxxe = 18 for node [VirtualMachineContainer.name CONTAINS eng-paas-t-eusw1a-1-], resultsId NSGroupExpEvaluationResults/1xxxxxxa-0000-0000-0000-3xxxxxxxxxx6
Note: The preceding log excerpts are only examples. Date, time, and environmental variables may vary depending on your environment.
VMware NSX-T Data Center
2x NSGs with same criteria are managed by same NSX Management node. After some time, resharding caused by proton restarts, one of the NSGs can get moved to a different NSX Management node, which will lead to this symptom.
This issue is resolved in NSX-T 3.0.3 and 3.1.0.
Workaround:
Restart proton on the NSX-T Manager node that owns the NSGroup, if its not clear which node own the NSG, restart proton on all 3 managers, one after the other.
From the manager's root shell: /etc/init.d/proton restart