Re: Thoughts on instance crash and RAC
From: joel garry <joel-garry_at_home.com>
Date: Tue, 20 Aug 2013 13:18:10 -0700 (PDT)
Message-ID: <b67a2ac2-eeaf-41e7-aa5b-9bb77a89e322_at_googlegroups.com>
On Tuesday, August 20, 2013 4:48:13 AM UTC-7, vsevolod afanassiev wrote:
> Some thoughts on instance crash and RAC:
>
> - Main selling point of RAC is that it increases availability: if one node crashes other nodes are still available. During presentations Oracle guys would crash an instance by killing PMON and show that the database is still accessible through other nodes.
>
> - However in my experience this isn't very realistic scenario. Oracle instances rarely experience such “instant” crash – an instance was running without problems and then few seconds later it is completely gone. More often an instance would struggle for a while – may be for 10 minutes, may be for half an hour. Things like latch waits, library cache wait, etc. would appear, may be with ORA-00600 and 7445 errors, may be 4031. However crash is unlikely or it will take a while. Instance "death" became slow and painful.
>
Date: Tue, 20 Aug 2013 13:18:10 -0700 (PDT)
Message-ID: <b67a2ac2-eeaf-41e7-aa5b-9bb77a89e322_at_googlegroups.com>
On Tuesday, August 20, 2013 4:48:13 AM UTC-7, vsevolod afanassiev wrote:
> Some thoughts on instance crash and RAC:
>
> - Main selling point of RAC is that it increases availability: if one node crashes other nodes are still available. During presentations Oracle guys would crash an instance by killing PMON and show that the database is still accessible through other nodes.
>
> - However in my experience this isn't very realistic scenario. Oracle instances rarely experience such “instant” crash – an instance was running without problems and then few seconds later it is completely gone. More often an instance would struggle for a while – may be for 10 minutes, may be for half an hour. Things like latch waits, library cache wait, etc. would appear, may be with ORA-00600 and 7445 errors, may be 4031. However crash is unlikely or it will take a while. Instance "death" became slow and painful.
>
You should probably google:
you probably don't need rac
jg
-- _at_home.com is bogus. http://www.zdnet.com/oracle-survey-examines-evolving-cfo-role-cooperation-with-cios-7000019640/Received on Tue Aug 20 2013 - 22:18:10 CEST