Re: Root cause for ORA-00471
Date: Mon, 8 Jul 2024 08:30:21 -0500
Message-ID: <CAP79kiTO8Cum6gYkNTBYZYfzfbJV=3LQTHKuROitA=2U9Na3iQ_at_mail.gmail.com>
So if your redo log switches are around 15 every hour (for example), they're not large enough.
You can check your log switches with this script:
On Mon, Jul 8, 2024 at 7:03 AM Eriovaldo Andrietta <ecandrietta_at_gmail.com> wrote:
> Hi,
>
> An instance version 12c terminated by PMON with the message :
> PMON(ospid:3996): terminating the instance due to error 471.
>
> Around the time that it happened I saw for all redo groups the event :
> LGWR all worker groups, but this event occurred in other periods. There are
> redo groups.
> Also I got that at this moment (a little before) there were a lot of
> sessions ON CPU.
> At the moment
>
> My doubts are
> - Where can I get the root cause for this error ?
> - Is there a way (queries) to check if 3 groups with 200mb each one is
> being enough for this environment? I don't see the interval of the
> checkpoint.
> The standard version can use the resource of threads for the redo log
> groups ?
> - Is there more than one possible cause for the error ORA-00471 ?
> - Is there any query that I can use to determine the % total amount of CPU
> used at this moment or interval ? ( I don't have access to the Enterprise
> Manager, It shows this data easily )
>
> I suspect that at this moment there were a lot of sessions in the cpu,
> dbwriter was with all groups busy and PMON based on some configuration
> terminated the instance.
> I am looking for evidence.
>
> Best Regards
> Eriovaldo
>
>
>
-- http://www.freelists.org/webpage/oracle-lReceived on Mon Jul 08 2024 - 15:30:21 CEST