Re: [cx-oracle-users] segmentation violations

[Fred Y. <fc...@im...>]

Thanks, Anthony. 

I have tried running with 'threaded' set to True and that does not help. 

Various combinations of argument values to my test script cause SIGSEGV in different places (or no SIGSEGV at all in some cases), but not correlating with any given option value. It's as if minor changes in the call stack cause the oracle client code to go off the rails, unrelated to the exact arguments passed down to the oracle client API. 

My application connects to Oracle only infrequently, polling for data updates on hourly cron jobs. So the complexity of connection pooling did not make sense per se. But I'll give it a try to see if it works around this problem. I'm not familiar with DRCP. 

The oracle database I'm connecting to comes embedded with another product (PowerSchool) and so we don't administer it directly, only through admin tools provided by PowerSchool. The diagnostics you mention would be on the oracle server side, right? 

-- 
Fred Yankowski 
fc...@im... +1-630-907-5019 

----- Original Message -----



Hi Fred, 

You seem to be experiencing a sort of memory corruption perhaps due to an overwrite somewhere. If you were using threads I would have immediately told you that you need to ensure threaded mode is enabled -- but I don't see multiple threads in use. You may wish to enable it anyway to see if you get consistent results, but that shouldn't be a problem. 

I have seen similar, highly intermittent, segfaults inside OCIServerAttach() myself, but only when using threads -- and they don't terminate in the same place. 

You could try using a session pool (cx_Oracle.SessionPool) with or without DRCP to see if that makes things happier. Not sure how many connections you are generally creating but if you are creating a few this would improve performance anyway! 

You can try enabling diagnostics for Oracle and seeing if interesting information shows up. You can also see if you get consistent backtraces. 

All of that said, I don't have this problem! Of course I'm not running the exact configuration you have. Depending on what you get from backtraces and diagnostics you can log a support request and see if they can help you. 

Anthony