Re: shared server configuration

From: Maureen English <maureen.english_at_alaska.edu>
Date: Thu, 21 Oct 2010 13:18:07 -0800
Message-ID: <4CC0AE0F.8010707_at_alaska.edu>

*click* lightbulb just went on...a session is always a session....

That number I pulled out of my hat (5000) was what I'd equate to 'students trying to register'. The application they're connecting through will be set to have a maximum of 2000 httpd processes connecting to the database. Those will be the shared server connections....

If I were to have 200 shared servers started, and each one could accommodate 10 of those httpd connections, it's possible that we'd still have 2000+ sessions, but they will be sharing the OS processes, thus using less memory and eliminating the problem with swapping.

Yes, I know that's an oversimplification, but now I see why I probably need to increase the sessions parameter...and can likely decrease the number of processes (if we ever get close to 2000 OS processes, we'd start swapping again!). We can also probably decrease the number of dispatchers...not sure when that number (8) was decided upon.... I'll likely leave shared_server_sessions unset for now. We only have this problem twice a year for less than an hour each time...and it's in the middle of the night when most of the employees are asleep!

Thanks for all the input!

• Maureen

Goulet, Richard wrote:
>
> I'm on Linux with Oracle 11.1.0.7. Max sessions per dispatcher
> is 972 (lsnrctl services will tell you). Now you say your expecting
> 5000 sessions max. So the dispatchers parameter should be set to
> ceil(5000/(972*.075)) or 69 dispatchers in my case which would cause me
> to visit the application designers since their connection pool probably
> isn't that large.

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Received on Thu Oct 21 2010 - 16:18:07 CDT