Re: SV - contention on RAC EXADATA

From: Pawel Smolarz <pawel.smolarz_at_nordea.com>
Date: Tue, 14 Jun 2016 12:18:09 +0200
Message-ID: <20160614121809.2f4705ea_at_nordea.com>


Hi,
In bind capture I have only one value: 60

One important think. Currently only one instance is active ... So, I know that this event appears only on RAC but why is so high if we have right now only one instance active

About changing a code. It is difficult to predict how long it takes to implement the changes - rather weeks than hours :/

Pozdrawiam / Regards,
Paweł

On Tue, 14 Jun 2016 09:58:35 +0000
Jonathan Lewis <jonathan_at_jlcomp.demon.co.uk> wrote:

>
>
> How big is v1 typically ?
> How important is it for the values on one node to be ordered with
> respect to the values on the other node(s) ? How important is it to
> minimise gaps across the entire cluster ? Do you control the code ?
>
>
>
> Regards
> Jonathan Lewis
> http://jonathanlewis.wordpress.com
> _at_jloracle
>
> ________________________________________
> From: oracle-l-bounce_at_freelists.org [oracle-l-bounce_at_freelists.org]
> on behalf of Pawel Smolarz [pawel.smolarz_at_nordea.com] Sent: 14 June
> 2016 10:14 To: oracle-l_at_freelists.org
> Subject: enq: SV - contention on RAC EXADATA
>
> Hi,
>
> Hi,
>
> On Exadata RAC database 12.1.0.2.0 we have problems with queries:
>
> SELECT schema.sequence_name.NEXTVAL
> FROM DUAL CONNECT BY ROWNUM <= :v1
>
> huge waits on Foreground Events:
> Event Waits Total Wait Time (sec) Wait Avg(ms) % DB time Wait Class
> DB CPU 2.1M 37.5
> resmgr:cpu quantum 1.1E+08 1.2M 11.21 21.6 Scheduler
> enq: SV - contention 83,224,234 1.1M 12.91 18.8 Other
>
> I know that is BUG but fix has been included in 12.1.0.1
>
> Anyone has a experience with this type of event?
> A lot of CPU has been consume by these sessions .
>
> Regards,
> Pawel
> --
> http://www.freelists.org/webpage/oracle-l
>
>

--
http://www.freelists.org/webpage/oracle-l
Received on Tue Jun 14 2016 - 12:18:09 CEST

Original text of this message