2.6.3 Monitoring after a failover occurs in databases in the mirroring configuration
The following figure summarizes how PFM - Agent for Microsoft SQL Server monitors the databases in the mirroring configuration after a failover occurs in those databases.
After a failover completes, the former mirror database on the host B moves online as the new principal database and the former principal database takes on the role of the mirror database.
After the failover completes, the instance of the PFM - Agent for Microsoft SQL Server which monitors the databases turned into the mirror databases (the instance A of the PFM - Agent for Microsoft SQL Server on the figure 2-6) collects the performance information from the databases other than the mirror databases.
Moreover, the instance of the PFM - Agent for Microsoft SQL Server which monitors the databases turned into the principal database (the instance B of the PFM - Agent for Microsoft SQL Server on the figure 2-6) collects the performance information from the principal databases and the databases in non-mirroring configuration.