COM call never comes back

[pmbtech]

I have an interesting problem. We have several apps that call a 3rd party DLL. We recently moved all our app to a new blade server and now every now and then when we make a call into the DLL it never returns. There is no error or anything. The calling app just hangs waiting for the return from the call. We move the apps back to a stand alone server and no problem. These apps have been running all Happy for years. The problem happens when we are really pounding the dll. The apps that only use it for a few calls hav no problem in either environment.
Has anyone seem this type of behaviour from running an app on a blade vs. stand-alone server?

 

[avanderlaan]

I have seen problems w/ similar appearance where the DCOM server does not properly segregate it's user and call state-specific data. In very high traffic situations the state of one caller gets partially overwritten by a "concurrent" call from another user. Because the reference counts are not decremented, some objects are also left behind. On a slow piece of hardware the window for this concurrency failure to occur is much smaller.