Failover of a highly available Portal for ArcGIS results in a misconfiguration of the pg_hba.conf file on the new primary portal which denies access to the PostgreSQL database.
The problem turned out to be that the standby portal that is being promoted to the primary was restarted during the promotion. This leaves the machine in an incomplete state.
対処法
1. Stop the Portal for ArcGIS service on all portals.2. Start the Portal for ArcGIS service on any one of the portals in the highly available site.3. Wait approximately 10 minutes until the portal comes online and assumes the primary role.4. Once the primary is firmly established and working, start the Portal for ArcGIS service on the other portal server in the highly available site.