Configure the PI AF connection string

The connection string, located in the AFService.exe.config file, defines the location of the PI AF SQL Server database and the security mode used to connect to the database. This string defines the location in a single subnet server configuration, as well as in a multi-subnet server configuration. In the multi-subnet configuration, when a connection attempt is made, the first IP address returned by DNS is used. If the first IP address corresponds to the site that is active, the connection attempt succeeds as normal. However, if the active site does not use the first listed IP address, the connection attempt will fail.

When an attempt is made to an availability group listener, connections to all IP addresses are attempted in parallel and if a connection attempt is successful, any pending connection attempts are discarded. This significantly reduces failover time for both single and multi-subnet server configurations.

1. On the AF server machine, open the AFService.exe.config file in the %PIHOME64%\AF folder.

2. Edit the server portion of the connect string so that it is directed at the availability group listener and the availability group listener’s port that you defined in Create a SQL Server availability group for use with PI AF.

   Specify the ListenerName,Port in the following string: <add key="connectString" value="Persist Security Info=False;Integrated Security=SSPI;server=ListenerName,Port;database=PIFD;Application Name=AF Application Server;MultiSubnetFailover=True;" />

   Specifying MultiSubnetFailover=True; ensures that connection attempts are made in parallel, and reduces failover time for both single and multi-subnet configurations.

3. Restart the PI AF server. The process of installing PI AF to a new availability group is complete.