Do ConnectRetryInterval and ConnectRetryCount Entity Framework SQL connection string settings interfer with Execution strategy?

Question

I wonder if ConnectRetryInterval and ConnectRetryCount Entity Framework SQL connection string settings make EF to retry DB failed updates. Please, see example of the EF connection string with the settings below

 <add key="MyConnectionString" value ="metadata=res://*/MyModel.csdl|res://*/MyModel.ssdl|res://*/MyModel.msl;provider=System.Data.SqlClient;provider connection string=&quot;data source=MySQLServer;initial catalog=My;integrated security=True;    ConnectRetryCount=4;ConnectRetryInterval=5; Connection Timeout=5; pooling=False;multipleactiveresultsets=True;App=EntityFramework&quot;" providerName="System.Data.EntityClient" />

Another question is about ConnectRetryInterval&ConnectRetryCount interference with DbExecutionStrategy/SqlAzureExecutionStrategy retry logic. Do connection settings retry first and Execution Strategy after that? Or, connection settings and Execution Strategy overlap each other's retry attempts depending on retry time intervals?

Thanks

Answer 1

I'm relying on this Microsoft white paper that covers "Idle Connection Resiliency" as the reference to answer your question. (Note that the white paper is in a downloaded MS Word/.docx article format.)

ConnectRetryCount and ConnectRetryInterval settings are associated with the MS SQL Server (v14+) drivers, independent of Entity Framework. Thus, as long both the server and the driver support it and the settings have been enabled in the connection string, they're expected to work within EF as well. However, in your example, Pooling is set to false. This will explicitly prevent pooling and open a new connection every time, so there will be no "idle" connection to work with.

EF Core's use of ExecutionStrategy is different since it can handle transaction errors and allow you to implement custom tactics depending on the type of error. You can also simply call EnableRetryOnFailure() to use the default ExecutionStrategy when configuring SQL provider options. There is no overlap between the SQL driver's idle connection retries and EF's transaction failure retries.