Re: process M000 holds library cache lock

From: Remigiusz Sokolowski <remigiusz.sokolowski_at_nordea.com>
Date: Wed, 28 Mar 2012 15:55:50 +0200
Message-ID: <4F731866.3020101_at_nordea.com>

as a summary for this post:
we started with killing M000 and this went well, but the next run of M000 repeated the hold of library cache mutex (so we were again in the same position) - then the only option was to restart and with still decreasing performance we did it, which helped of course

Regards
Remigiusz

W dniu 28.03.2012 15:50, De DBA pisze:
> Hi Remigiusz,
>
> Most likely nothing else than a restart of the process. It is a slave
> process of mmon. As my test instance has no m000 at the moment, I just
> killed mmon to prove the point.. :-)
>
> This is what happened:
>
> $ pgrep -lf mmon_TST2
> 14079 ora_mmon_TST2
> $ sudo kill -9 14079
> [sudo] password for lingent:
> $ pgrep -lf
> mmon_TST2 # MMON
> on the TST2 instance is dead
> $ tail /u00/oracle/diag/rdbms/tst2/TST2/trace/alert_TST2.log
> Starting background process VKRM
> Wed Mar 28 22:00:00 2012
> VKRM started with pid=21, OS id=20915
> Wed Mar 28 22:00:30 2012
> Thread 1 advanced to log sequence 59 (LGWR switch)
> Current log# 2 seq# 59 mem# 0: /u00/oracle/oradata/TST2/redo02.log
> Wed Mar 28 23:42:02 2012
> *Restarting dead background process MMON* # It's
> dead has been noticed by the instance
> Wed Mar 28 23:42:02 2012
> MMON started with pid=15, OS id=22229 #
> mmon is restarted.8-)
> $ pgrep -lf mmon_TST2
> 22229 ora_mmon_TST2
>
> Since brutally killing mmon has as only effect that it is restarted, I
> would conclude that any slaves of it can be safely killed as well...
> (but maybe others have one that they can kill to test)
>
> Hth,
> Tony
>
>
> On 28/03/12 18:47, Remigiusz Sokolowski wrote:

>> hi,
>>
>> anyone tried to kill M000 - what are possible implications?
>> Will the instance die?
>> It just took library cache mutex (X) and holds for very considerable
>> amount of time.
>>
>> Regards
>> Remigiusz

>

-- 
Pole nakazi

----------------------------------------------------------------------
Remigiusz Sokolowski <remigiusz.sokolowski_at_nordea.com>
pos   : DBA at DIiUSI
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Received on Wed Mar 28 2012 - 08:55:50 CDT