Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.In order to get it fixed, firstly, developers should check .NET code within applications. In some cases, the developers I worked with found infinite loops or slow codes which spent much time before sending SQL queries to the database engine, as a result of this, the timeout threshold was reached at application level and, obviously, the error was raised. By the way, the following error could also be related to timeout:
Timeout expired. The timeout period elapsed prior to obtaining a connection from the pool. This may have occurred because all pooled connections were in use and max pool size was reached.
Unable to connect to SQL Server session database.Having checked the application, you can increase the 'CommandTimeout' property value to 60 seconds (if it is not enough then change to 120 or 180, and also considerate using 0 (unlimited) which should be a workaround while the problem is being traced and fixed). That is all for now, let me know any remarks you may have. Thanks for reading. Stay tuned.