Answer: This can occur normally when the target database is running on the secondary (mirror) server and failover occurs; for example:

• Foxhound is successfully gathering samples from both the primary and secondary (mirror) servers in a High Availability (HA) setup.

• The primary server fails, and the secondary (mirror) server automatically becomes the primary server as part of the failover process.

• The Foxhound sampling session that was connected to the old primary server loses its connection (because the primary server failed).

• That Foxhound sampling session automatically connects to the server which used to be the secondary (mirror) server and now is the primary server.

• The other Foxhound sampling session remains connected to the server which used to be the secondary (mirror) server and now is the primary server.

• ...which means both Foxhound sessions are connected to the same database, hence the "Duplicate Foxhound sampling sessions" message.

Foxhound Sampling Session #1... Connection string name: HA_Demo_16_Primary Connection string: SERVER=primary_demo; UID=dba; PWD=sql; HOST=Computer1:55501,Computer2:55502; DRIVER=SQL Anywhere Native; Sampling OK ... Machine: XPS ... Server: partner2_demo ... Database: demo ... Updatable primary database. Arbiter is connected. Partner is disconnected, synchronizing. Duplicate Foxhound sampling sessions. There is more than one Foxhound connection to this target database.

Foxhound Sampling Session #2... Connection string name: HA_Demo_16_Secondary Connection string: SERVER=secondary_demo; UID=dba; PWD=sql; HOST=Computer1:55501,Computer2:55502; DRIVER=SQL Anywhere Native; Sampling OK ... Machine: XPS ... Server: partner2_demo ... Database: demo ... Updatable primary database. Arbiter is connected. Partner is disconnected, synchronizing. Duplicate Foxhound sampling sessions. There is more than one Foxhound connection to this target database.