Why is this error happening a lot "asp.net, sql server"?

Question

I have this error which happen many times on my site:
"A network-related or instance-specific error occurred while establishing a connection to SQL Server. The server was not found or was not accessible. Verify that the instance name is correct and that SQL Server is configured to allow remote connections. (provider: TCP Provider, error: 0 - An operation on a socket could not be performed because the system lacked sufficient buffer space or because a queue was full.)"

My site files are on a server and the database on another server, but on the same network.
Anyone know what may cause this problem and how to solve?
Notes:
- When i restart the website server the problem solve and everything work fine.
- Sure my sql server allow remote connections from this website server

Answer 1

It's a pretty generic error when the application can't get to the database. Perhaps you are leaving connections open after using them? There could be a limit on the amount of concurrent connections by user or server.

Answer 2

It's a networking error of some kind, or you're specifying the instance name incorrectly. I've recently seen both cases. In one case, I had moved a connection string from one system, to another system that had a different instance name installed. In another case, I had a server running in a Virtual Machine - about ten minutes after the machine was resumed from suspension, the machine would lose its DHCP lease (and therefore its connectivity).

It could be just about anything, and you'll have to go find out, perhaps by using a network monitor program like Microsoft Network Monitor 3.2.

Answer 3

I found a good article talking about this error, i think it shows the real reason
Understanding the error “An operation on a socket could not be performed because the system lacked sufficient buffer space or because a queue was full.”