Re: ASSM in 10g RAC doesnt seem work that well

I am still interested in this.

Martic, sure lets' ignore the waits, but real times speak for themselves. +50% in execution time.

And the fact that I've confirmed that L1 block ownership is all from the same instance is very strange. Almost smells like a bug. I can't even begin to imagine the nightmare of trying to explain this to Oracle.

--
Christo Kutrovsky
Database/System Administrator
The Pythian Group

The Pythian Group
On Tue, 29 Mar 2005 10:02:23 -0800 (PST), Martic Zoran
<zoran_martic_at_yahoo.com> wrote:


> Christo,

> 

> I could not reproduce the same CPU time for ASM and

> non-ASM tablespaces in all mine environments.

> I have only Solaris/HP-UX environments and so cannot

> test Linux.

> 

> It could be OS specific of course. This is why I

> mentioned many times my environment and what I tested.

> 

> I am not using any specific parameter.

> Maybe tuned a little bit interconnection between nodes

> in the past and that is all.

> 

> In your case you need to tune waits because that is

> what is the different in your case.

> Nothing to do with the CPU usage because it is the

> same.

> I assume your test is far from the real scenario?

> 

> Maybe you just proved when pushing with very high

> speed DML from both nodes then the collisions on

> blocks are more frequent and so pushing RAC to the end

> where performances starting to drop because of global

> cache.

> This is very natural. As faster you push both sides of

> RAC you are going to pay the price.

> In this particular case old non-ASSM with two

> freelists gave you better results.

> 

> I assume your HW/SW/interconnect environment may cause

> these things. You should be aware about the RAC tuning

> and global cache issues with bad interconnection.

> 

> Regards,

> Zoran

> 

> --- Christo Kutrovsky <kutrovsky.oracle_at_gmail.com>

> wrote:

> 

> > So right now we're basically lost?

> >

> > - We dont know why ASSM is using less CPU in

> > Martic's case and not in mine

> > - We dont know why ASSM is not working as expected

> > in my RAC test

> > case, and not in his.

> >

> > Any ideas ?

> >

> > Martic, why dont you post all your non-default

> > parameters ? Could it

> > be something OS specific, i did not see any LINUX

> > results or I missed

> > it ?

> >

> >

> 

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-- 
Christo Kutrovsky
Database/System Administrator
The Pythian Group
--
http://www.freelists.org/webpage/oracle-l