Entity Framework Query Timeout

Question

In my controller I have the following code:

    public ActionResult Syslogs(string IPAddress) {
        IEnumerable<Syslogd> syslogs = db.Syslogds.Take(100).ToList();

        if (!String.IsNullOrEmpty(IPAddress)) {
            syslogs = db.Syslogds.Where(s => s.MsgHostname == IPAddress).Take(100).ToList();
        }

        return View(syslogs.ToList());
    }

The query times out whenever I pass a certain value to the IPAddress variable. I'm not sure why that is happening or how I can prevent it. Does the value not exist in the database or is it just taking a long time to find it? Here is the error message I receive:

An exception of type 'System.Data.Entity.Core.EntityCommandExecutionException' occurred in EntityFramework.SqlServer.dll but was not handled in user code

Additional information: An error occurred while executing the command definition. See the inner exception for details.

The inner exception:

{"Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding."}

Answer 1

It's possible that the value doesn't exist, but a Timeout just means that the query didn't complete in the time given for the command to execute. I think the default timeout for EF is 30 seconds for commands.

Basic question, but, if your Syslogd table has many records, is there an index on MsgHostname?

Answer 2

As Ryan said default timeout for EF is 30 seconds for commands . So you can increase the execution timeout time.

By using CommandTimeOut :

// Specify a timeout for queries in this context, in seconds.
context.CommandTimeout = 120;  

Reference

Consider this also:

1. Moreover you are using .ToList() which is force query execution by immediate and i think you can avoid that to improve the performance.
2. IEnumerable is suitable for querying data from in-memory collections like List, Array etc.But not suitable for querying data from out-memory (like remote database, service) collections and paging.

So i strongly recommend to use IQueryable in this case.

Reference
codeproject

IQueryable Vs. IEnumerable in terms of LINQ to SQL queries