I have configured database mirroring between two servers at a distance 40 miles away from each other.
Server specifications: SQL Server 2008,Standard Edition 64-bit
This is same for principal,mirror and witness. The configuration is high-safety with automatic failover
Initially we tested our .net application(web application) on both the principal and mirror and made sure that the login is not orphaned.
Things run fine generally.But sometimes on the mirror server,I see login failed attempts:
Login failed for user 'd0main\user'. Reason: Failed to open the explicitly specified database. [CLIENT: xx.xx.x.x] Message Error: 18456, Severity: 14, State: 38.
This error appears 3-4 times a day but not more than that.
My question to the experts is:If the principal is alive so why the application tries to connect to mirror.The default time-out for a .net webpage is 30 seconds,so is it possible that the application tries to connect principal and after 30 seconds even if principal is alive,it assumes that it is dead and thus tries to open a connection to mirror where it fails.
Please help me with this problem.