Handling FQDN Nulling Issues During HA Failover in the SolarWinds Platform

• After adding an FQDN entry under the Websites table in the SolarWinds Platform database upon HA failover or switchover, the FQDN values in the Websites table are reset to NULL.
• Verification shows that SSL certificates are applied on both HA pollers.
• Manual intervention is required to update the FQDN in the database after each failover.
• Investigation reveals the root cause: the SSL certificate's Common Name (CN) is invalid or does not match the expected FQDN, causing the system to reject the certificate and clear the FQDN field.

• Issued To (CN) Field: Must match the real host FQDN exactly or use a wildcard certificate valid for the domain.
• Certificate Chain: The entire certificate chain must be trusted by the server.
• CRL/OCSP Accessibility: Certificate Revocation List (CRL) or Online Certificate Status Protocol (OCSP) endpoints must be reachable to validate the certificate status.
• Subject Alternative Name (SAN): Should include all relevant hostnames, especially if a common DNS hostname is shared between HA pollers.

The SSL certificate's Common Name (CN) is invalid or does not match the expected FQDN, causing the system to reject the certificate and clear the FQDN field.

To prevent the FQDN from being reset to NULL during failover, you can modify the HA failover SQL scripts to hardcode the FQDN value.

1. Backup Existing Scripts
   Navigate to the folder:
   C:\Program Files\SolarWinds\Orion\HighAvailability\Plugins\Sql\OnStart
   Make a backup copy of all files in this directory before proceeding.
2. Edit HA SQL Script
   Open the file HAMainEngineOnStart.sql or HAAdditionalEngineOnStart.sql in a text editor with administrative privileges.
3. Modify the Update Query
   Locate the following SQL query:

   UPDATE [dbo].[Websites] SET [ServerName]=@hostname, [FQDN]=@FQDN WHERE [ServerName]=@oldHostname;
   

   Replace it with a query that sets the FQDN explicitly:

   UPDATE [dbo].[Websites] SET [ServerName]=@hostname, [FQDN]='{yourHostName}' WHERE [ServerName]=@oldHostname;
   

   Replace {yourHostName} with the actual FQDN you want to preserve.
4. Apply Changes on Both Pollers
   Perform the above modification on both the active and standby HA poller servers.
5. Force Failover and Verify
   Trigger a failover and verify that the FQDN in the Websites table remains correctly set.

• Validate SSL certificates on all HA pollers using MMC Certificates snap-in to ensure the CN and SAN fields are correct and trusted.
• Confirm that the FQDN in the Websites table matches the CN or SAN entries of the SSL certificate.
• Update the hosts file or DNS records as needed to ensure proper name resolution.
• Restart IIS and SolarWinds services after making changes to ensure settings are applied.