Hi Conrad, Thanks for the email.
1 - I agree completely. I'm actually not using the thread-pool explicitly. My comments were regarding remoting's built-in usage of the thread-pool. 2 - This is very interesting and is probably the explanation of my "problem". I will have to do some further testing. Thanks again. I will update with my results as soon as I get a chance to re-test. Regards, Jeremy -----Original Message----- From: Discussion of advanced .NET topics. [mailto:[EMAIL PROTECTED] On Behalf Of Conrad Frix Sent: Sunday, March 23, 2008 2:23 PM To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM Subject: Re: [ADVANCED-DOTNET] Remoting, Threading and Concurrency Jeremy, If I were you I would eliminate the ThreadPool just to be sure that's not your issue. The reason for this is twofold 1) You probably shouldn't be using the ThreadPool for long running tasks. From http://www.yoda.arachsys.com/csharp/threads/ "In general, you should create a new thread "manually" for long-running tasks, and use the thread pool only for brief jobs. The thread pool can only run so many jobs at once, and some framework classes use it internally, so you don't want to block it with a lot of tasks which need to block for other things. The examples in this article mostly use manual thread creation. On the other hand, for short-running tasks, particularly those created often, the thread pool is an excellent choice" 2) When the CPU untilization is high the pool will block requests until the CPU goes down. From http://blogs.msdn.com/tess/archive/2006/03/27/net-memory-leak-unblock-my -finalizer.aspx We know from previous case studies that the CPU utilization shows the CPU utilization of the whole system, not only the CPU utilization of this process, how could that possibly have anything to do with the threadpool? Well, surprise surprise, it does. This piece of information is stored in a variable by the framework because it is one of the factors that determine whether or not we will be creating new threads. In particular, if the CPU utilization is over 80% we don't create any new threads... and this is why we are not creating any new threads in this case. If this doesn't fix your problem. I suggest you get a memory dump and use WinDbg to figure out what is blocking your short running task. -Conrad On Sat, Mar 22, 2008 at 12:49 PM, Jeremy Byron <[EMAIL PROTECTED]> wrote: > Hrm....all valid points. Yes, this is just a test app and is being > run all on one machine, single proc (don't ask...I'm not in charge of > purchasing :). > > I'll try splitting it out and maybe using a db call for the "long > running" process. See if it picks up another thread while waiting for > db to return (that's my biggest concern. I don't want my machine > sitting and waiting for a long-running db call to return). > > Jeremy > > ________________________________ > > From: Discussion of advanced .NET topics. on behalf of Stoyan Damov > Sent: Thu 3/20/2008 5:59 PM > To: ADVANCED-DOTNET@DISCUSS.DEVELOP.COM > Subject: Re: [ADVANCED-DOTNET] Remoting, Threading and Concurrency > > > > Surely you want SingleCall, not Singleton. > > Couple of questions: > > Q1: How many machines you're using for the test (I guess 1 for test > client and 1 for server)? If 1, then not sure what you're testing but > maybe Q2 needs an answer. > > Q2. What's your machine like and particularly how many CPUs? > Hint: if you say 1 wtf :), if 2, then think about it (you have 1 UI > thread > + > 2 background threads + at least one for GC +at least 1 main on > server-side > + > 1 GC...) but in any case Q3 needs an answer > > Q3. What does "loops for N seconds" mean - do you actually spin loop like: > while (current time - start time < timeout) { }? > If yes, then depends on previous answer, but in any case Windows sucks > BIG TIME (compared to, say, Solaris) with thread switching, where even > 1 thread spin loops like that. > > HTH > > Cheers, > Stoyan > > On Thu, Mar 20, 2008 at 3:30 PM, Jeremy Byron <[EMAIL PROTECTED]> > wrote: > > > Hello everyone, > > > > I have been struggling with this for a few weeks now. I have > > searched on the web high and low, purchased "advanced" remoting > > books, searched newsgroups and these discussion group's archives. I > > see hints of explanations/solutions, but nothing that seems to work > > or explain what is going on. > > > > We are not doing anything special. We are just trying to create > > some objects that will be remoted and accessed by WinForms clients > > and ASP.NET <http://asp.net/> clients. But we are noticing that the > requests are being > > processed on the server sequentially. So basically, the remoting > > object processes one call at a time, with concurrent requests > > blocking. > > > > I have created a test project (source is available, but I suspect > > someone will be able to answer this without needing to see the > > source. This seems like such a basic issue I'm sure someone has some > > insight). Very basic. > > > > One remoted object - two methods: LongRunningProcess() and > > ShortRunningProcess() > > Server is Console app - just sets up the remoting and remotes the > > one object (no config file, all done via code) Client is a WinForms > > application. Single form with two buttons, one for each of the > > methods (and a corresponding textbox to see the results). Each > > button spawns a worker thread to make the remote call, so calls are > > not blocking on client-side. Using TCP/Binary channel/formatter. > > > > Each of the remote functions is the same, enter a tight loop for a > > specified period of time then return a string with time loop > > started, time loop ended, thread id and threadPool status of each > > thread. LongRunning just loops for 30 seconds and shortRunning loops > > for 3. > > > > So here's the problem. > > > > When I run the test, I click "Start Long Running" then immediately > > click "Start Short Running". After 30 seconds, the LongRunning > > returns, then 3 seconds later ShortRunning returns. Server Thread > > IDs are the same and it is a threadpool thread. (Client ThreadIDs > > are different > > obviously) Obviously the calls are blocking so the remoting host can > > only process one request at a time??? > > > > Now, I try putting a "Thread.Sleep(250)" in the loop of the long > > running, now when I click my two buttons, ShortRunning returns after > > 3 seconds and LongRunning returns after 30 seconds and they both > > have different threadIDs and both threads are threadPool threads. > > > > I was under the impression that on the remoting server side, the > > requests were handled via the threadpool and hence did not block > > each other. But from my results it sounds more complicated then > > that. It would seem to be quite detrimental to throughput to have > > requests blocking each other like this. And I would think that if > > it was a requirement for me to spawn worker threads in my > > remotedObject (or use the sleep method) that would be documented > > somewhere. But I've never seen it anywhere. > > > > I've tried using SingleCall and Singleton for my remoted object (one > > post I read said Singleton was multi-threaded whereas Singlecall was > > not). I've even tried changing my host to IIS (and using the > > remoting config file) with the same results. > > > > Does anyone have any insight on how to get my object to process > > requests concurrently? > > > > Thanks in advance. > > > > Jeremy > > > > =================================== > > This list is hosted by DevelopMentor(R) http://www.develop.com < > http://www.develop.com/> > > > > View archives and manage your subscription(s) at > > http://discuss.develop.com <http://discuss.develop.com/> > > > > =================================== > This list is hosted by DevelopMentor(R) http://www.develop.com < > http://www.develop.com/> > > View archives and manage your subscription(s) at > http://discuss.develop.com <http://discuss.develop.com/> > > > > =================================== > This list is hosted by DevelopMentor(R) http://www.develop.com > > View archives and manage your subscription(s) at > http://discuss.develop.com > =================================== This list is hosted by DevelopMentor(r) http://www.develop.com View archives and manage your subscription(s) at http://discuss.develop.com =================================== This list is hosted by DevelopMentor® http://www.develop.com View archives and manage your subscription(s) at http://discuss.develop.com
