This issue is resolved in vCenter server 7.0 U3h or higher versions.
Please refer to :-
VM
ware vCenter Server 7.0 Update 3h Release Notes Workaround:
This workaround can be applied either at
vCenter Server 7.0u3f itself that is the failed state or
vCenter Server 7.0u3d which is before starting upgrading to 7.0u3f.
1. Connect to vCenter Server SSH session with root credentials.
2. Connect to WCP database using the below command:
PGPASSFILE=/etc/vmware/wcp/.pgpass /opt/vmware/vpostgres/current/bin/psql -d VCDB -U wcpuser -h localhost
3. Run the following command to check the entries that have
instance_id as null:
SELECT cluster, instance_id FROM cluster_db_configs WHERE instance_id is NULL;
4. Update the instance_id in cluster_db_configs to random UUID where it is null:
UPDATE cluster_db_configs SET instance_id=gen_random_uuid() WHERE instance_id is NULL;
5. WCP service (and any other service that has not started after the upgrade) needs to be restarted once the DB entry has been fixed.
service-control --status --all
service-control --restart --all (--stop or --start)
or
service-control --restart wcp (--stop or --start)
6. Re-run Step 2 and 3 to verify
instance_id is not NULL. Now vCenter Server must be up and running.
7. At this stage if the user have applied this workaround at vCenter Server 70u3d, then proceed upgrading to vCenter Server 70u3f or If the user has applied the workaround at vCenter Server 70u3f, then visit the VMware Appliance Management Interface (VAMI) or CLI installer and resume the upgrade.