Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding. The statement has been terminated

Question

I have many users on my web site (20000-60000 per day), which is a download site for mobile files. I have remote access to my server (windows server 2008-R2).
I\'ve

Answer 1

TLDR:

1. Rebooting both application and DB servers is the quickest fix where data volume, network settings and code haven't changed. We always do so as a rule
2. May be indicator of failing hard-drive that needs replacement - check system notifications

---

I have often encountered this error for various reasons and have had various solutions, including:

1. refactoring my code to use SqlBulkCopy
2. increasing Timeout values, as stated in various answers or checking for underlying causes (may not be data related)
3. Connection Timeout (Default 15s) - How long it takes to wait for a connection to be established with the SQL server before terminating - TCP/PORT related - can go through a troubleshooting checklist (very handy MSDN article)
4. Command Timeout (Default 30s) - How long it takes to wait for the execution of a query - Query execution/network traffic related - also has a troubleshooting process (another very handy MSDN article)
5. Rebooting of the server(s) - both application & DB Server (if separate) - where code and data haven't changed, environment must have changed - First thing you must do. Typically caused by patches (operating system, .Net Framework or SQL Server patches or updates). Particularly if timeout exception appears as below (even if we do not use Azure):
   • System.Data.Entity.Core.EntityException: An exception has been raised that is likely due to a transient failure. If you are connecting to a SQL Azure database consider using SqlAzureExecutionStrategy. ---> System.Data.Entity.Core.EntityCommandExecutionException: An error occurred while executing the command definition. See the inner exception for details. ---> System.Data.SqlClient.SqlException: A transport-level error has occurred when receiving results from the server. (provider: TCP Provider, error: 0 - The semaphore timeout period has expired.) ---> System.ComponentModel.Win32Exception: The semaphore timeout period has expired