SQL Azure连接突然失败

Question

I have a website hosted on GoDaddy server and many users access this website with their respective username and passwords. My database is in Azure. All of a sudden when the users of this website try to access the website with their username and password they fail to be identified as valid users though they are valid.

consequently when such a thing happens almost for more than 5 mins no user can login to the website. but i can very well connect to the database from my local server or through the azure portal.

the series of errors that gets logged into event viewer are as follows:

1. System.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

2. System.Data.SqlClient.SqlException: a transport-level error has occured when sending the request to the server.(provider:TCP provider,error:0 - An existing connection was forcibly closed by the remote host.)

3. System.Data.SqlClient.SqlException: 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 - A connection attempt failed because the connected party did not properly respond after a period of time, or established connection failed because connected host has failed to respond.)

4. SourceEdge.BCL.BCLException: Unable to Execute ---> System.Data.SqlClient.SqlException: Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding.

5. System.ArgumentNullException: Value cannot be null. Parameter name: connection

after the error shown in 5 occurs all the subsequent logins will result in invalid user though the values are not null.

Can you tell me why this error happens all of a sudden. but it gets back to normal after a few minutes or even takes hours sometimes.

Answer 1

I'm not sure if you're aware of some pitfalls regarding connection handling to SQL Azure. The SQL Azure service might close connections at any time for some reasons. What you need is so called Transient condition handling. Not sure if this is the problem, but if you'are not aware of this, I'd suggest you read the following resources:

Microsoft Technet - Windows Azure SQL Database Connection Management

Microsoft Technet - Retry Logic for Transient Failures in Windows Azure SQL Database