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."}

On a side note, you are always executing the first query even if you are overwriting those values with a filter on IP. You should move the first query to the else clause to avoid doing any extra unnecessary work. — Wouter de Kort, Oct 29 '14 at 20:05
How many records does Syslogd have? Is the database on a separate machine? What is network bandwidth usage? — Louis Michael, Oct 29 '14 at 22:02

score 3 · Answer 1 · answered Oct 29 '14 at 20:03

3

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?

answered Oct 29 '14 at 20:03

Ryan Nigro

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I have discovered that the record just doesn't exist in the database. I guess my question now is how can I check for that before executing the query? I have tried db.Syslogd.Any() but that didn't work. – mdk09 Oct 30 '14 at 16:19

score 1 · Answer 2 · edited Dec 08 '22 at 21:25

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

Or by using Database.CommandTimeout

// or for all object in context (in seconds)
context.Database.CommandTimeout = 120;

Consider this also:

Moreover you are using .ToList() which is forcing immediate query execution and I think you can avoid that to improve the performance.
IEnumerable is suitable for querying data from in-memory collections like List, Array etc, but it's 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

Entity Framework Query Timeout

2 Answers2