I have a multithreaded server C++ program that uses MSXML6 and continuously parses XML messages, then applies a prepared XSLT transform to produce text. I am running this on a server with 4 CPUs. Each thread is completely independent and uses its own transform object. There is no sharing of any COM objects among the threads. This works ...
So we've been told that one source of TM Enq contention can be unindexed FK's. My question is which one. I have an INSERT INTO Table_B that is recording TM Enq Wait. It contains a PK that is the parent to other tables and it has columns that are FK constrained to other PKs. So which FKs need indexed. That table's columns or its childr...
While debugging an issue with our system, I have discovered a thread contention that is causing a bottleneck. I need to explain the phenomenon to other people involved in handling this issue. Some of them are not from development team (yet, they are reasonably technical). So what type of diagrams can be used to depict threading issues...
Hi, I'm expecting that the load on the software I'm developing will increase over the next couple of months. Therefore I did some stress tests, and gathered some performance data with perfmon. For one of the data I would like to have more information, and that's the contention rate. So my question would be, if one of you knows, if it i...
Our Tomcat web application feels slow when it is used by a couple hundred users. The servers are in a hosting company and their reports doesn't show any problem with bandwith or cpu workload, so I suspect that the reason of the slowdowns can be because of contention on some legacy code that we encapsulated under synchronized calls becaus...
we experience with some regularity contention on a database table, and would like to evaluate a number of different options for resolving this issue. in order to do so, i need to reproduce in a test case, contention on a table (any table) with repeatable reliability. the approach i'm considering would be to reverse the semantics of a l...
Hi, QUESTION: How can I handle potential contention between two separate threads accessing the same Sqlite database? BACKGROUND: I have a C# Winforms application that uses Sqlite via ADO.net. I do have a backgroundworker thread in the winforms application. I have noticed that I can get an exception when both the main thread, and the...
Continuing the discussion from http://stackoverflow.com/questions/2902984/understanding-vs2010-c-parallel-profiling-results but more to the point: I have many threads that work in parallel (using Parallel.For/Each), which use many memory allocations for small classes. This creates a contention on the global memory allocator thread. Is...
I just ran the Visual Studio 2010 Thread Profiler against my Azure code and noticed I'm getting a LOT of contentions. My code is blocked more often than it is running! My worker has no custom threading logic in it at all. It is a simple While loop which asks various queues if they have work. I make an instance of the QueueRepositoryClas...
I'm working on a PHP webapp that does automatic resizing of images and I'm thinking of storing the cached copies on the NFS mounted NAS so it's easy for me to flush the cache when images are updated. The only thing I'm worried about is what happens in general with NFS if 2 or more of the servers in the cluster are trying to create the s...
Hi All I have just learnt that in C language malloc function comes with the issue of thread contention when used in a multi-threaded applications. In C++ does operator new suffer from the same problem? If yes what tecnhique can I use to avoid this that sounds like a big penalty in the application performance? Thaks AFG ...
Looking for a minimal, futex-based implementation of a single-writer/multiple-readers lock requiring no space overhead beyond a single 4-byte futex state variable. Some background: I have an application which will embed a lock within each of tens to hundreds of millions of small objects. Because of the very fine grained nature of the l...