Re: Oracle Performance on Sunfire T2000

From: Martin Berger <martin.a.berger_at_gmail.com>
Date: Fri, 13 Feb 2009 21:33:45 +0100
Message-Id: <15082EEE-64FA-4F35-95EA-56F770348EF3_at_gmail.com>

it's just about the runqueue (I guess). If the runqueue in your 4 fast CPUs is 'long', you will be happy any of the 'slow' 128 Threads process the task and release the latch.
Of course, if you do not utilize 4 CPUs to the limits, you will not need 128 Threads at all.

But still I'm just telling in pure theory, in Summer I will have my new T2+s and have to prove it. Until then, it's pure theory.

br
  Martin

--
Martin Berger    http://berxblog.blogspot.com





> There's one more catch with slow single thread execution with high  

> parallelism in Oracle. If you migrate from 4 fast CPUs to 128 slow  

> threads, you will have much heavier latch contention on busy  

> latches. Doing whatever work under protection of a latch will  

> probably take longer, thus the latch is held for longer. And instead  

> of 3-4 concurrent threads trying to get the latch at the same time  

> you'll potentially have few hundred ones....

>

> Glenn Fawcett has quite a few useful blog entries about Oracle  

> performance on Sun CMT processors http://blogs.sun.com/glennf/tags/throughput

>

> Tanel.

>

>

> From: oracle-l-bounce_at_freelists.org [mailto:oracle-l-bounce_at_freelists.org 

> ] On Behalf Of Matthew Zito

> Sent: 12 February 2009 19:02

> To: jifjif_at_gmail.com; oracle-l_at_freelists.org

> Subject: RE: Oracle Performance on Sunfire T2000

>

>

> We have a couple of t1000s, and while our workload is a little odd  

> (we're an automation company, so all our several hundred databases  

> do is get installed, patched, upgraded, uninstalled, etc.), anything  

> involving data dictionary activities (running catupgd.sql, etc. -  

> high-cpu single threaded activities) is slower on the t1000s than  

> our ancient v210s.

>

> Supposedly the t1000/2000 are perfect for J2EE apps - lots of  

> threads, not a lot of heavy-lifting, parallelization of execution is  

> the most critical piece.

>

> Thanks,

> Matt

>

> --

> Matthew Zito

> Chief Scientist

> GridApp Systems

> P: 646-452-4090

> mzito_at_gridapp.com

> http://www.gridapp.com

>

>







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http://www.freelists.org/webpage/oracle-l




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Received on Fri Feb 13 2009 - 14:33:45 CST