Question

I am inserting a lot of data into a RavenDB database; about 2500000 records. That needs to be completed in less time as possible.

I use a list to hold Task object returned by SaveChangesAsync:

session.Store(loc);

splitter++;
if (splitter % 2048 == 0)
{
    var t = session.SaveChangesAsync();
    tasks.Add(t);

    if (tasks.Count == 2)
    {
        Task.WaitAll(tasks.ToArray());
        tasks.Clear();
    }
}

This code is running on machine with an i7 (8 core) and 12 GB ram. It works if the number of Task objects I hold is 2 (as you see in the code) but if I increase this number to 8 (number of cores) I receive a System.IndexOutOfRangeException (and sometimes an System.AggregateException which says: “Raven.Abstractions.Exceptions.ConcurrencyException: PUT attempted on document ‘X/I’ using a non current etag”).

What is the problem here?

Thanks

Answer 1

You can have only a single async pending operation per sessions.