Multithreaded Apps

[mentcher]

Has anyone had problems with multithreaded applications under a heavy load? We have an application with 12 threads and each thread has it's own session component. Each thread processes about 40 select queries multiple times in a loop. With a small number of iternations everything is OK. When it gets large, about 1000, more often then not one or more of the threads seems to hang on a query. It's never the same thread or the same query. Any help or insight would be appreciated.

Thanks for your time,
Ara

 

[Marco Kalter]

If each thread has its own session and database access components, then the threads are very much isolated (as far as Direct Oracle Access and the Oracle client are concerned). Do you know if the application hangs on the client or on the server? Are there any errors in SQL*Net trace files or server trace files? Do the threads access any global variables?

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Marco Kalter
Allround Automations

 

[mentcher]

It seems to hand on the client. We checked with the dba and there didn't seem to be any problems on the server. There wasn't any trace files on the client. We upgraded our Oracle client to 8.0.6 and I've been testing all day with no problems. As far as global variables, the datamodule instances are declared as threadvar in the datamodule units interface section and created/destroyed within the thread's execute method. It might not be the best design but it was an inherited project and we haven't had time to redesign it.

Ara