Friday, September 2, 2016

Entity Framework: Timeout when initializing a database on SQL Azure

A colleague came to me with the following problem:

“I’m using Entity Framework and a DropCreateDatabaseIfModelChanges DB Initializer to setup the database. This works perfect locally on my system but when I try to use a database in SQL Azure, I always get a SqlException with the following message:  Timeout expired.  The timeout period elapsed prior to completion of the operation or the server is not responding." How can I fix this?

My first reaction was, don’t do this. I’m not a big fan of the DB Initializers and prefer to generate the DDL and do the rollout using my release pipeline. But during development this could save us some time. So let’s see how we can fix this…

The reason we have this issue is because the creation of a database on SQL Azure can take some time(at least more time than the default timeout(60 seconds)), explaining the Timeout expired message. So the question becomes how can we change the default timeout?

There are multiple timeout values that can play a role:

  • We have the connection timeout. This can be configured in the connection string:
<connectionStrings>
     <add name="MyContext" connectionString="Server=tcp:azure_server_name.database.windows.net,1433;Database=azure_database_name;User ID=azure_user_account@azure_server_name;Password=azure_password;Trusted_Connection=False;Encrypt=True;Connection Timeout=180"
          providerName="System.Data.SqlClient" />
</connectionStrings>
  • We have the command timeout. This can be configured inside our DBContext instance:
public MyContext() : base("name=MyContext")
{
    // three minute command timeout
    this.Database.CommandTimeout = 180;
}

DbMigrationsConfiguration.CommandTimeout=180;//Seconds

No comments: