Why does SqlAzureExecutionStrategy not handle error: 19 - Physical connection is not usable

Question

Full exception:

System.Data.Entity.Core.EntityCommandExecutionException: An error occurred while executing the command definition. See the inner exception for de         


        

Answer 1

If you have explicitly opened the connection, this is a design decision. Microsoft says:

From the profiler trace we observe that the same connection is used for each query database query. This is by design and as discussed early, i.e. when a connection is explicitly opened by the developer it tells EF not to open/reopen a connection for each command. The series of Audit Login/Logout events to retrieve the customer entity or address entity are not submitted as we saw in Case #1 and #2. This means we cannot implement a retry policy for each individual query like I showed earlier. Since the EntityConnection has been assigned to the ObjectContext, EF takes the position that you really truly want to use one connection for all of your queries within the scope of that context. Retrying a query on an invalid or closed connection can never work, a System.Data.EntityCommandExecutionException will be thrown with an inner SqlException contains the message for the error. (see http://blogs.msdn.com/b/appfabriccat/archive/2010/12/11/sql-azure-and-entity-framework-connection-fault-handling.aspx)

Also, and my apologies if you have already seen this, but Julia at the Data Farm goes into quite of bit of detail for transient errors. I'm not sure if 'Physical connection is not usable' is considered transient - it's not included in the list for System.Data.SqlClient.SqlException in the code for SqlAzureExecutionStrategy - but it might be worth looking at: http://thedatafarm.com/data-access/ef6-connection-resiliency-for-sql-azure-when-does-it-actually-do-its-thing/ (and her follow-up, referenced in the linked article).

I haven't looked deeply into Azure since about 2012, but I hope this helps.