on 12-17-2014 3:49 AM
Hi experts ,
I am getting following error in Oracle ( 11.2.0.3)
Redo log buffer 2228 < 4000 - 2,228 < 4000 redo entries |
When I run sql for redo buffer allocation retries, I get as below
SELECT NAME, VALUE FROM V$SYSSTAT WHERE NAME = 'redo buffer allocation retries';
NAME VALUE
---------------------------------------------------------------- ----------
redo buffer allocation retries 74955
Everyday it increases by 200
Current LOG_BUFFER size is 20MB
show parameter LOG_BUFFER;
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
log_buffer integer 19955712
How should I resolve this issue ? by increase LOG_BUFFER size ? How do I calculate optimal size ?
Hello Abu Zahir,
This is cused when the active log file has filed up and Oracle is waiting for disk space to be allocated for the redo log entries. Space is created by performing a log switch.
Increase the number of redologs groups or increase their sizes.
Br
Tomislav
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I have to say that I never saw the mentioned error.
are you sure it is an error?, where do you see it? can you paste it here with some lines before and after?
It seems that you have the redo log set to 19 MB.
Do you have set the parameter or it is the default value?
How many CPUs Has your system.
In an SAP system, usually we recommend not to set this parameter (check note 1627481).
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Abu Zahir Al-Mamun wrote:
We have 16 CPU ,log_buffer is set to 20MB and redolog file size is 500 MB which are default value
-Al Mamun
Hi,
1.- How many redo logs groups do you have?
2.- What is the size of the redo log (you indicate 500 but then you talk about the default value which is 50, unless SAP has changed it recently.
3.- what is the logswitch frequency?
4.- When was the DB restarted?
5.- what are the values for the Oracle statistics "redo log space requests", "redo entries" and "redo log space wait time"
That seems to be a "ratio" and as all ratios it might be useless.
Hi Fidel,
Fidel Vales wrote:
That seems to be a "ratio" and as all ratios it might be useless.
i want to give you 5000 thumbs up for that, but unfortunately SCN allows only one. The only thing i still wonder is why SAP (CCMS tools, etc.) does no get the rid of it.
Regards
Stefan
P.S.: By the way the redo buffer handling is much more complicated than just setting parameter log_buffer (or adding multiple redo log groups), e.g. private redo / IMU, multiple public redo buffers / threads, dynamic switching between old (one change, one record, one allocation) and new private / public redo handling. However troubleshooting this is impossible through a forum and without system access.
"I've seen things you wouldn't believe"
The only thing i still wonder is why SAP (CCMS tools, etc.) does no get the rid of it.
probably a mix of dinosaurs and power,
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