RE: log buffer space wait

2003-09-03 Thread Avnish.Rastogi




I have 
one question regarding these wait times, may be dump. In the following wait 
events what is the unit of measurement for Time, I believe its in seconds as per 
the documentation. If yes then here stats 
are collected for only 51.23 Minutes (Appx 3073 seconds), how come 
Oracle is showing 566,516 seconds wait for log buffer space. I would appreciate 
if someone can explain.
 
Thanks
 
 

Top 5 Timed 
Events
~~ 
% Total
Event   
Waits    Time (s) Ela Time
 
 --- 
log buffer 
space    
1,817,258 566,516    
56.24
latch 
free  
2,964,652 334,120    
33.17
log file 
sync  
55,230  43,488 
4.32
buffer busy waits  
62,839  
26,129 2.59
CPU 
time   


  -Original Message-From: VIVEK_SHARMA 
  [mailto:[EMAIL PROTECTED]Sent: Tuesday, September 02, 2003 
  6:39 AMTo: Multiple recipients of list ORACLE-LSubject: 
  log buffer space wait 
  
  At a Benchmark a 
  particular Processing + DML intensive batch Job (Accounts Interest 
  Calculation) is experiencing 
  “log buffer space” wait 
  .
   
  Config 
:-
  On Solaris 9 
  
  Cpu_count = 
  72
  Oracle 
  9.2
  Online Redo logfiles are 
  on a RAID 0+1 Volume (NOT Raw or RAID 1) Log_buffer = 10 M
  $ sar Command Outpuit %wio 
  only about 6 % for Volume containing the redo logfiles
  Database in NOARCHIVELOG 
  mode
   
  Qs. How can we reduce this 
  wait event ? Would RAW / RAID 1 for redo logfiles help ?
  Qs. Could this be a Bug 
  ?
   
  *
  STATSPACK report 
  for
   
  DB 
  Name DB Id    
  Instance Inst Num Release 
  Cluster Host
   --- 
    --- --- 
  BM2 
    3727568246 
  bm2 
  1 9.2.0.3.0   NO  
  sleepy
   
      
  Snap Id Snap Time  
  Sessions Curs/Sess Comment
      
  --- --  - 
  ---
  Begin 
  Snap: 240 01-Sep-03 03:09:41   
  23   1.5
    End 
  Snap: 241 01-Sep-03 04:00:55   
  24   1.7
     
  Elapsed:   
  51.23 (mins)
   
  Top 5 Timed 
  Events
  ~~ 
  % Total
  Event   
  Waits    Time (s) Ela Time
   
   --- 
  log buffer 
  space    
  1,817,258 566,516    
  56.24
  latch 
  free  
  2,964,652 334,120    
  33.17
  log file 
  sync  
  55,230  43,488 
  4.32
  buffer busy waits  
  62,839  
  26,129 2.59
  CPU 
  time   
  22,018 2.19
    
  -
  Wait Events for DB: 
  BM2  Instance: bm2  Snaps: 240 -241
  -> s  - 
  second
  -> cs - centisecond 
  - 100th of a second
  -> ms - millisecond 
  -    1000th of a second
  -> us - microsecond - 
  100th of a second
  -> ordered by wait time 
  desc, waits desc (idle events last)
   
      
     Avg
   
  Total Wait   wait    Waits
  Event   
  Waits   Timeouts   Time (s)   
  (ms) /txn
   
   -- -- -- 
  log buffer 
  space    
  1,817,258    139    
  566,516    312 54.4
  latch 
  free  
  2,964,652    892,594    
  334,120    113 88.8
  log file 
  sync  
  55,230 21,210 
  43,488    787  
  1.7
  buffer busy 
  waits  
  62,839 10,250 
  26,129    416  
  1.9
   
   
  Latch Activity for DB: 
  BM2  Instance: bm2  Snaps: 240 -241
   
     
  Pct    Avg   
  Wait 
  Pct
    
  Get  Get   
  Slps   Time   NoWait 
  NoWait
  Latch   
  Requests  Miss  /Miss    
  (s) Requests   Miss
   
  -- -- -- --  --
  post/wait 
  queue  
  97,357    4.7    0.4    
  577    1,871,155  249.5
  process 
  allocation  
  751    7.2    3.0 
  10  747    
  0.5
  process group 
  creation   

RE: log buffer space wait

2003-09-03 Thread Jared . Still

These are cumalitive times for a few hundred processes.

Jared








<[EMAIL PROTECTED]>
Sent by: [EMAIL PROTECTED]
 09/03/2003 10:34 AM
 Please respond to ORACLE-L

        
        To:        Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]>
        cc:        
        Subject:        RE: log buffer space wait


I have one question regarding these wait times, may be dump. In the following wait events what is the unit of measurement for Time, I believe its in seconds as per the documentation. If yes then here stats are collected for only 51.23 Minutes (Appx 3073 seconds), how come Oracle is showing 566,516 seconds wait for log buffer space. I would appreciate if someone can explain.
 
Thanks
 
 
Top 5 Timed Events
~~                                                     % Total
Event                                               Waits    Time (s) Ela Time
  --- 
log buffer space                                1,817,258     566,516    56.24
latch free                                      2,964,652     334,120    33.17
log file sync                                      55,230      43,488     4.32
buffer busy waits                                  62,839      26,129     2.59
CPU time                                                       
-Original Message-
From: VIVEK_SHARMA [mailto:[EMAIL PROTECTED]
Sent: Tuesday, September 02, 2003 6:39 AM
To: Multiple recipients of list ORACLE-L
Subject: log buffer space wait 

At a Benchmark a particular Processing + DML intensive batch Job (Accounts Interest Calculation) is experiencing 
"log buffer space" wait .
 
Config :-
On Solaris 9 
Cpu_count = 72
Oracle 9.2
Online Redo logfiles are on a RAID 0+1 Volume (NOT Raw or RAID 1) Log_buffer = 10 M
$ sar Command Outpuit %wio only about 6 % for Volume containing the redo logfiles
Database in NOARCHIVELOG mode
 
Qs. How can we reduce this wait event ? Would RAW / RAID 1 for redo logfiles help ?
Qs. Could this be a Bug ?
 
*
STATSPACK report for
 
DB Name         DB Id    Instance     Inst Num Release     Cluster Host
 ---   --- --- 
BM2           3727568246 bm2                 1 9.2.0.3.0   NO      sleepy
 
            Snap Id     Snap Time      Sessions Curs/Sess Comment
            --- --  - ---
Begin Snap:     240 01-Sep-03 03:09:41       23       1.5
  End Snap:     241 01-Sep-03 04:00:55       24       1.7
   Elapsed:               51.23 (mins)
 
Top 5 Timed Events
~~                                                     % Total
Event                                               Waits    Time (s) Ela Time
  --- 
log buffer space                                1,817,258     566,516    56.24
latch free                                      2,964,652     334,120    33.17
log file sync                                      55,230      43,488     4.32
buffer busy waits                                  62,839      26,129     2.59
CPU time                                                       22,018     2.19
          -

Wait Events for DB: BM2  Instance: bm2  Snaps: 240 -241
-> s  - second
-> cs - centisecond -     100th of a second
-> ms - millisecond -    1000th of a second
-> us - microsecond - 100th of a second
-> ordered by wait time desc, waits desc (idle events last)
 
                                                                   Avg
                                                     Total Wait   wait    Waits
Event                               Waits   Timeouts   Time (s)   (ms)     /txn
  -- -- -- 
log buffer space                1,817,258        139    566,516    312     54.4
latch free                      2,964,652    892,594    334,120    113     88.8
log file sync                      55,230     21,210     43,488    787      1.7
buffer busy waits                  62,839     10,250     26,129    416      1.9
 
 

Latch Activity for DB: BM2  Instance: bm2  Snaps: 240 -241
 
                                           Pct    Avg   Wait                 Pct
                              Get          Get   Slps   Time       NoWait NoWait
Latch                       Requests      Miss  /Miss    (s)     Requests   Miss
 -- -- -- --  --
post/wait queue                  97,357    4.7    0.4    577    1,871,155  249.5
process allocation                  751    7.2    3.0     10          747    0.5
process group creation            1,502    0.0             0            0
redo allocation 

RE: log buffer space wait

2003-09-03 Thread DENNIS WILLIAMS
Vivek - When you've got Cary Millsap quoting Steve Adams, well the advice
just doesn't get any better than that. Go with their advice. As I pointed
out, I replied because at that point nobody had posted yet.

Dennis Williams
DBA, 80%OCP, 100% DBA
Lifetouch, Inc.
[EMAIL PROTECTED] 


-Original Message-
Sent: Tuesday, September 02, 2003 12:34 PM
To: Multiple recipients of list ORACLE-L


http://www.ixora.com.au/q+a/0008/24162020.htm


Cary Millsap
Hotsos Enterprises, Ltd.
http://www.hotsos.com

Upcoming events:
- Hotsos Clinic 101 in Sydney
- Hotsos Symposium 2004, March 7-10 Dallas
- Visit www.hotsos.com for schedule details...


-Original Message-
DENNIS WILLIAMS
Sent: Tuesday, September 02, 2003 12:04 PM
To: Multiple recipients of list ORACLE-L

Vivek
Good question. At this point I haven't seen any replies to your
request.
The specific wait points to the log buffer itself as being too small,
not
particularly the redo logs themselves. Your init.ora parameters show
this
buffer as being only 10-meg. I would suggest you increase it. But your
redo
logs are only 10-meg themselves, so you should consider increasing the
size
of the logs while you are at it or you may hit that as the next limit.
Since
the redo logs are continuously written, it is usually recommended that
they
be on a device that is devoted to redo logs.



Dennis Williams 
DBA, 80%OCP, 100% DBA 
Lifetouch, Inc. 
[EMAIL PROTECTED] 

-Original Message-
Sent: Tuesday, September 02, 2003 8:39 AM
To: Multiple recipients of list ORACLE-L



At a Benchmark a particular Processing + DML intensive batch Job
(Accounts
Interest Calculation) is experiencing 

"log buffer space" wait .

 

Config :-

On Solaris 9 

Cpu_count = 72

Oracle 9.2

Online Redo logfiles are on a RAID 0+1 Volume (NOT Raw or RAID 1)
Log_buffer
= 10 M

$ sar Command Outpuit %wio only about 6 % for Volume containing the redo
logfiles

Database in NOARCHIVELOG mode

 

Qs. How can we reduce this wait event ? Would RAW / RAID 1 for redo
logfiles
help ?

Qs. Could this be a Bug ?

 



*

STATSPACK report for

 

DB Name DB IdInstance Inst Num Release Cluster Host

 ---   --- ---


BM2   3727568246 bm2 1 9.2.0.3.0   NO
sleepy

 

Snap Id Snap Time  Sessions Curs/Sess Comment

--- --  -
---

Begin Snap: 240 01-Sep-03 03:09:41   23   1.5

  End Snap: 241 01-Sep-03 04:00:55   24   1.7

   Elapsed:   51.23 (mins)

 

Top 5 Timed Events

~~ %
Total

Event   WaitsTime (s)
Ela
Time

  ---


log buffer space1,817,258 566,516
56.24

latch free  2,964,652 334,120
33.17

log file sync  55,230  43,488
4.32

buffer busy waits  62,839  26,129
2.59

CPU time   22,018
2.19

  -




Wait Events for DB: BM2  Instance: bm2  Snaps: 240 -241

-> s  - second

-> cs - centisecond - 100th of a second

-> ms - millisecond -1000th of a second

-> us - microsecond - 100th of a second

-> ordered by wait time desc, waits desc (idle events last)

 

   Avg

 Total Wait   wait
Waits

Event   Waits   Timeouts   Time (s)   (ms)
/txn

  -- -- --


log buffer space1,817,258139566,516312
54.4

latch free  2,964,652892,594334,120113
88.8

log file sync  55,230 21,210 43,488787
1.7

buffer busy waits  62,839 10,250 26,129416
1.9

 

 




Latch Activity for DB: BM2  Instance: bm2  Snaps: 240 -241

 

   PctAvg   Wait
Pct

  Get  Get   Slps   Time
NoWait
NoWait

Latch   Requests  Miss  /Miss(s)
Requests
Miss

 -- -- -- --

--

post/wait queue  97,3574.70.4577
1,871,155
249.5

process allocation  7517.23.0 10
747
0.5

process group creation1,5020.0 0
0

redo allocation  24,482,283   13.50.4 ##
0

redo copy   

Re: log buffer space wait

2003-09-02 Thread Jared . Still

After doing some reading on this, I suspect that your log files are too small.

I don't see any info on log file size in this post, or at least, I can't find it.

A large percentage of log buffer space waits occurr immediately after a 
log switch, so if you're switching logs very frequently, you will get a lot
of these waits.

A 10 meg buffer is actually pretty large. Since IIRC, you can only fill the
log to 1/3 or 1 meg, whichever comes first, there's not a lot of benefit
to making the log buffer larger.

You will find quite a bit of info on this at Steve Adams site, www.ixora.com.au

HTH

Jared







"Tanel Poder" <[EMAIL PROTECTED]>
Sent by: [EMAIL PROTECTED]
 09/02/2003 08:24 AM
 Please respond to ORACLE-L

        
        To:        Multiple recipients of list ORACLE-L <[EMAIL PROTECTED]>
        cc:        
        Subject:        Re: log buffer space wait


Hi!
 
What's the value for _log_simultaneous_copies parameter? You might want to manually increase it, even though it depends on CPU_COUNT when left default.
I personally would increase log_buffer size as well, if you got that many CPUs and concurrent sessions.
 
Tanel.
 
- Original Message - 
From: VIVEK_SHARMA 
To: Multiple recipients of list ORACLE-L 
Sent: Tuesday, September 02, 2003 4:39 PM
Subject: log buffer space wait 

At a Benchmark a particular Processing + DML intensive batch Job (Accounts Interest Calculation) is experiencing 
"log buffer space" wait .
 
Config :-
On Solaris 9 
Cpu_count = 72
Oracle 9.2
Online Redo logfiles are on a RAID 0+1 Volume (NOT Raw or RAID 1) Log_buffer = 10 M
$ sar Command Outpuit %wio only about 6 % for Volume containing the redo logfiles
Database in NOARCHIVELOG mode
 
Qs. How can we reduce this wait event ? Would RAW / RAID 1 for redo logfiles help ?
Qs. Could this be a Bug ?
 
*
STATSPACK report for
 
DB Name         DB Id    Instance     Inst Num Release     Cluster Host
 ---   --- --- 
BM2           3727568246 bm2                 1 9.2.0.3.0   NO      sleepy
 
            Snap Id     Snap Time      Sessions Curs/Sess Comment
            --- --  - ---
Begin Snap:     240 01-Sep-03 03:09:41       23       1.5
  End Snap:     241 01-Sep-03 04:00:55       24       1.7
   Elapsed:               51.23 (mins)
 
Top 5 Timed Events
~~                                                     % Total
Event                                               Waits    Time (s) Ela Time
  --- 
log buffer space                                1,817,258     566,516    56.24
latch free                                      2,964,652     334,120    33.17
log file sync                                      55,230      43,488     4.32
buffer busy waits                                  62,839      26,129     2.59
CPU time                                                       22,018     2.19
          -

Wait Events for DB: BM2  Instance: bm2  Snaps: 240 -241
-> s  - second
-> cs - centisecond -     100th of a second
-> ms - millisecond -    1000th of a second
-> us - microsecond - 100th of a second
-> ordered by wait time desc, waits desc (idle events last)
 
                                                                   Avg
                                                     Total Wait   wait    Waits
Event                               Waits   Timeouts   Time (s)   (ms)     /txn
  -- -- -- 
log buffer space                1,817,258        139    566,516    312     54.4
latch free                      2,964,652    892,594    334,120    113     88.8
log file sync                      55,230     21,210     43,488    787      1.7
buffer busy waits                  62,839     10,250     26,129    416      1.9
 
 

Latch Activity for DB: BM2  Instance: bm2  Snaps: 240 -241
 
                                           Pct    Avg   Wait                 Pct
                              Get          Get   Slps   Time       NoWait NoWait
Latch                       Requests      Miss  /Miss    (s)     Requests   Miss
 -- -- -- --  --
post/wait queue                  97,357    4.7    0.4    577    1,871,155  249.5
process allocation                  751    7.2    3.0     10          747    0.5
process group creation            1,502    0.0             0            0
redo allocation              24,482,283   13.5    0.4 ##            0
redo copy                       675,177   99.6    1.1 ##   21,986,833 

Re: log buffer space wait

2003-09-02 Thread Tanel Poder



Hi!
 
What's the value for _log_simultaneous_copies 
parameter? You might want to manually increase it, even though it depends on 
CPU_COUNT when left default.
I personally would increase log_buffer size as 
well, if you got that many CPUs and concurrent sessions.
 
Tanel.
 

  - Original Message - 
  From: 
  VIVEK_SHARMA 
  To: Multiple recipients of list ORACLE-L 
  
  Sent: Tuesday, September 02, 2003 4:39 
  PM
  Subject: log buffer space wait 
  
  
  At a Benchmark a 
  particular Processing + DML intensive batch Job (Accounts Interest 
  Calculation) is experiencing 
  “log buffer space” wait 
  .
   
  Config 
:-
  On Solaris 9 
  
  Cpu_count = 
  72
  Oracle 
  9.2
  Online Redo logfiles are 
  on a RAID 0+1 Volume (NOT Raw or RAID 1) Log_buffer = 10 M
  $ sar Command Outpuit %wio 
  only about 6 % for Volume containing the redo logfiles
  Database in NOARCHIVELOG 
  mode
   
  Qs. How can we reduce this 
  wait event ? Would RAW / RAID 1 for redo logfiles help ?
  Qs. Could this be a Bug 
  ?
   
  *
  STATSPACK report 
  for
   
  DB 
  Name DB Id    
  Instance Inst Num Release 
  Cluster Host
   --- 
    --- --- 
  BM2 
    3727568246 
  bm2 
  1 9.2.0.3.0   NO  
  sleepy
   
      
  Snap Id Snap Time  
  Sessions Curs/Sess Comment
      
  --- --  - 
  ---
  Begin 
  Snap: 240 01-Sep-03 03:09:41   
  23   1.5
    End 
  Snap: 241 01-Sep-03 04:00:55   
  24   1.7
     
  Elapsed:   
  51.23 (mins)
   
  Top 5 Timed 
  Events
  ~~ 
  % Total
  Event   
  Waits    Time (s) Ela Time
   
   --- 
  log buffer 
  space    
  1,817,258 566,516    
  56.24
  latch 
  free  
  2,964,652 334,120    
  33.17
  log file 
  sync  
  55,230  43,488 
  4.32
  buffer busy waits  
  62,839  
  26,129 2.59
  CPU 
  time   
  22,018 2.19
    
  -
  Wait Events for DB: 
  BM2  Instance: bm2  Snaps: 240 -241
  -> s  - 
  second
  -> cs - centisecond 
  - 100th of a second
  -> ms - millisecond 
  -    1000th of a second
  -> us - microsecond - 
  100th of a second
  -> ordered by wait time 
  desc, waits desc (idle events last)
   
      
     Avg
   
  Total Wait   wait    Waits
  Event   
  Waits   Timeouts   Time (s)   
  (ms) /txn
   
   -- -- -- 
  log buffer 
  space    
  1,817,258    139    
  566,516    312 54.4
  latch 
  free  
  2,964,652    892,594    
  334,120    113 88.8
  log file 
  sync  
  55,230 21,210 
  43,488    787  
  1.7
  buffer busy 
  waits  
  62,839 10,250 
  26,129    416  
  1.9
   
   
  Latch Activity for DB: 
  BM2  Instance: bm2  Snaps: 240 -241
   
     
  Pct    Avg   
  Wait 
  Pct
    
  Get  Get   
  Slps   Time   NoWait 
  NoWait
  Latch   
  Requests  Miss  /Miss    
  (s) Requests   Miss
   
  -- -- -- --  --
  post/wait 
  queue  
  97,357    4.7    0.4    
  577    1,871,155  249.5
  process 
  allocation  
  751    7.2    3.0 
  10  747    
  0.5
  process group 
  creation    
  1,502    
  0.0 
  0    
  0
  redo 
  allocation 
   24,482,283   
  13.5    0.4 
  ##    
  0
  redo 
  copy   
  675,177   99.6    1.1 ##   
  21,986,833  708.0
   
  init.ora Parameters for 
  DB: BM2  Instance: bm2  Snaps: 240 -241
   
    
  End value
  Parameter 
  Name    
  Begin 
  value   
  (if different)
  - 
  - --
  _db_block_lru_latches 
  128
  audit_trail   
  FALSE
  background_dump_dest  
  /oracle/ora92-64/rdbms/log/bdump
  compatible    
  9.2.0.3
  control_f

RE: log buffer space wait

2003-09-02 Thread Cary Millsap
http://www.ixora.com.au/q+a/0008/24162020.htm


Cary Millsap
Hotsos Enterprises, Ltd.
http://www.hotsos.com

Upcoming events:
- Hotsos Clinic 101 in Sydney
- Hotsos Symposium 2004, March 7-10 Dallas
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-Original Message-
DENNIS WILLIAMS
Sent: Tuesday, September 02, 2003 12:04 PM
To: Multiple recipients of list ORACLE-L

Vivek
Good question. At this point I haven't seen any replies to your
request.
The specific wait points to the log buffer itself as being too small,
not
particularly the redo logs themselves. Your init.ora parameters show
this
buffer as being only 10-meg. I would suggest you increase it. But your
redo
logs are only 10-meg themselves, so you should consider increasing the
size
of the logs while you are at it or you may hit that as the next limit.
Since
the redo logs are continuously written, it is usually recommended that
they
be on a device that is devoted to redo logs.



Dennis Williams 
DBA, 80%OCP, 100% DBA 
Lifetouch, Inc. 
[EMAIL PROTECTED] 

-Original Message-
Sent: Tuesday, September 02, 2003 8:39 AM
To: Multiple recipients of list ORACLE-L



At a Benchmark a particular Processing + DML intensive batch Job
(Accounts
Interest Calculation) is experiencing 

"log buffer space" wait .

 

Config :-

On Solaris 9 

Cpu_count = 72

Oracle 9.2

Online Redo logfiles are on a RAID 0+1 Volume (NOT Raw or RAID 1)
Log_buffer
= 10 M

$ sar Command Outpuit %wio only about 6 % for Volume containing the redo
logfiles

Database in NOARCHIVELOG mode

 

Qs. How can we reduce this wait event ? Would RAW / RAID 1 for redo
logfiles
help ?

Qs. Could this be a Bug ?

 



*

STATSPACK report for

 

DB Name DB IdInstance Inst Num Release Cluster Host

 ---   --- ---


BM2   3727568246 bm2 1 9.2.0.3.0   NO
sleepy

 

Snap Id Snap Time  Sessions Curs/Sess Comment

--- --  -
---

Begin Snap: 240 01-Sep-03 03:09:41   23   1.5

  End Snap: 241 01-Sep-03 04:00:55   24   1.7

   Elapsed:   51.23 (mins)

 

Top 5 Timed Events

~~ %
Total

Event   WaitsTime (s)
Ela
Time

  ---


log buffer space1,817,258 566,516
56.24

latch free  2,964,652 334,120
33.17

log file sync  55,230  43,488
4.32

buffer busy waits  62,839  26,129
2.59

CPU time   22,018
2.19

  -




Wait Events for DB: BM2  Instance: bm2  Snaps: 240 -241

-> s  - second

-> cs - centisecond - 100th of a second

-> ms - millisecond -1000th of a second

-> us - microsecond - 100th of a second

-> ordered by wait time desc, waits desc (idle events last)

 

   Avg

 Total Wait   wait
Waits

Event   Waits   Timeouts   Time (s)   (ms)
/txn

  -- -- --


log buffer space1,817,258139566,516312
54.4

latch free  2,964,652892,594334,120113
88.8

log file sync  55,230 21,210 43,488787
1.7

buffer busy waits  62,839 10,250 26,129416
1.9

 

 




Latch Activity for DB: BM2  Instance: bm2  Snaps: 240 -241

 

   PctAvg   Wait
Pct

  Get  Get   Slps   Time
NoWait
NoWait

Latch   Requests  Miss  /Miss(s)
Requests
Miss

 -- -- -- --

--

post/wait queue  97,3574.70.4577
1,871,155
249.5

process allocation  7517.23.0 10
747
0.5

process group creation1,5020.0 0
0

redo allocation  24,482,283   13.50.4 ##
0

redo copy   675,177   99.61.1 ##
21,986,833
708.0

 

init.ora Parameters for DB: BM2  Instance: bm2  Snaps: 240 -241

 

  End
value

Parameter NameBegin value   (if
different)

- -
--

_db_block_lru_latches 128

RE: log buffer space wait

2003-09-02 Thread DENNIS WILLIAMS
Vivek
Good question. At this point I haven't seen any replies to your request.
The specific wait points to the log buffer itself as being too small, not
particularly the redo logs themselves. Your init.ora parameters show this
buffer as being only 10-meg. I would suggest you increase it. But your redo
logs are only 10-meg themselves, so you should consider increasing the size
of the logs while you are at it or you may hit that as the next limit. Since
the redo logs are continuously written, it is usually recommended that they
be on a device that is devoted to redo logs.



Dennis Williams 
DBA, 80%OCP, 100% DBA 
Lifetouch, Inc. 
[EMAIL PROTECTED] 

-Original Message-
Sent: Tuesday, September 02, 2003 8:39 AM
To: Multiple recipients of list ORACLE-L



At a Benchmark a particular Processing + DML intensive batch Job (Accounts
Interest Calculation) is experiencing 

"log buffer space" wait .

 

Config :-

On Solaris 9 

Cpu_count = 72

Oracle 9.2

Online Redo logfiles are on a RAID 0+1 Volume (NOT Raw or RAID 1) Log_buffer
= 10 M

$ sar Command Outpuit %wio only about 6 % for Volume containing the redo
logfiles

Database in NOARCHIVELOG mode

 

Qs. How can we reduce this wait event ? Would RAW / RAID 1 for redo logfiles
help ?

Qs. Could this be a Bug ?

 


*

STATSPACK report for

 

DB Name DB IdInstance Inst Num Release Cluster Host

 ---   --- ---


BM2   3727568246 bm2 1 9.2.0.3.0   NO  sleepy

 

Snap Id Snap Time  Sessions Curs/Sess Comment

--- --  -
---

Begin Snap: 240 01-Sep-03 03:09:41   23   1.5

  End Snap: 241 01-Sep-03 04:00:55   24   1.7

   Elapsed:   51.23 (mins)

 

Top 5 Timed Events

~~ %
Total

Event   WaitsTime (s) Ela
Time

  ---


log buffer space1,817,258 566,516
56.24

latch free  2,964,652 334,120
33.17

log file sync  55,230  43,488
4.32

buffer busy waits  62,839  26,129
2.59

CPU time   22,018
2.19

  -




Wait Events for DB: BM2  Instance: bm2  Snaps: 240 -241

-> s  - second

-> cs - centisecond - 100th of a second

-> ms - millisecond -1000th of a second

-> us - microsecond - 100th of a second

-> ordered by wait time desc, waits desc (idle events last)

 

   Avg

 Total Wait   wait
Waits

Event   Waits   Timeouts   Time (s)   (ms)
/txn

  -- -- --


log buffer space1,817,258139566,516312
54.4

latch free  2,964,652892,594334,120113
88.8

log file sync  55,230 21,210 43,488787
1.7

buffer busy waits  62,839 10,250 26,129416
1.9

 

 




Latch Activity for DB: BM2  Instance: bm2  Snaps: 240 -241

 

   PctAvg   Wait
Pct

  Get  Get   Slps   Time   NoWait
NoWait

Latch   Requests  Miss  /Miss(s) Requests
Miss

 -- -- -- -- 
--

post/wait queue  97,3574.70.45771,871,155
249.5

process allocation  7517.23.0 10  747
0.5

process group creation1,5020.0 00

redo allocation  24,482,283   13.50.4 ##0

redo copy   675,177   99.61.1 ##   21,986,833
708.0

 

init.ora Parameters for DB: BM2  Instance: bm2  Snaps: 240 -241

 

  End value

Parameter NameBegin value   (if
different)

- -
--

_db_block_lru_latches 128

audit_trail   FALSE

background_dump_dest  /oracle/ora92-64/rdbms/log/bdump

compatible9.2.0.3

control_files /lbmdb02/bm2/data02/control_01_bm

core_dump_dest/oracle/ora92-64/rdbms/log/cdump

cursor_sharingEXACT

cursor_space_for_ti

RE: log buffer space wait

2003-09-02 Thread Mladen Gogala
Title: Message



They 
say that the silence is golden, but I don't think that the rule applies to the 
mailing lists.
 
 
--Mladen GogalaOracle DBA 

  
  -Original Message-From: 
  [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of zhu 
  chaoSent: Tuesday, September 02, 2003 11:29 AMTo: 
  Multiple recipients of list ORACLE-LSubject: Re: log buffer space 
  wait 
 
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Re: log buffer space wait

2003-09-02 Thread zhu chao