Question

I have ASP.NET MVC app and WCF Service.

Here is my code in MVC:


public ActionResult Service()
{
    var filterRepository = new FilterRepository();
    var idFilter = 78005;
    var filter = filterRepository.GetById(idFilter);
/* 1) We need such code:

    var resultLineViews = new ResultLineViewRepository().GetByIdFilter(idFilter);
    resultLineViews.ToList().ForEach(z => z.Remove());
*/

/* 2) or something else

    var filter1 = filterRepository.GetById(idFilter);
    filter1.HasTotals = !filter1.HasTotals;

*/
var client = new WinService.CalculatorFacadeClient();

client.Calculate(1, idFilter);

// 3) we can send another idFilter
//client.Calculate(1, 132);
client.Close();

return RedirectToAction("Index");

}

client.Calculate() calls method Calculate inside service, and the service is hosted in Windows Application, so we have two separated domains.

client.Calculate() calls this method:


private FilterInfo GetFilterInfo(int id)
{
    FilterInfo userSettings = null;
var sessionConfiguration = new SessionConfiguration(SessionOptions.AutoActivation){};

using (var session = Program.Domain.OpenSession(sessionConfiguration))
{

    using (var transactionScope = session.OpenTransaction())
    {
        /// 4) ------------ on this line we can get EXCEPTION, if 1) or 2) is uncommented - TimeoutException.
        var filter = StaticStorage.FilterRepository.GetById(id);

        userSettings = new FilterInfo
        {
            IsTemporary = filter.IsTemporary
        };

        transactionScope.Complete();
    }

}
return userSettings;

}

It all works.

But if we uncomment 1) or 2) in first code block - we got exception on 4) in second code block.

There are two different domains and application contexts, because first method invoked by MVC, second - by WinApp.

First code block runs inside transaction and opened session (Xtensive.Practices.Web.SessionManager).

That exception throws even if we put 3) instead of above line. So we have some table lock, maybe.

Any ideas?

Accepted Answer

The answer is copied from the comments to original question.

Seems it is expected timeout. You are changing filter instance within one transaction and trying to read the same instance within another one. So attempt to read locked instance is timing out as it must be. As an option you can try to switch isolation level to Snapshot or ReadCommitted+Snapshot. Or try not to change filter.

Additionally if you need to access changed filter in context of Calculate method you in a trouble because you need to commit to make changes visible but SessionManager controls transaction by its own. In this case filter settings may be sent as Calculate method parameters

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