OWB RT Log Switches and Parameter

Good day, all.
For various reasons we find ourselves with an OWB data base repository release 10.1 and the target ODS data base release 10.2.0.4. This is an approved configuration within the Oracle Product Matrix. Both sit on the same MS 2003 64-bit Server. We have had an on going issue that causes the OWB RT Log File to switch sometimes 20 to 30 (although it is rare this many times) during one OWF Workflow session. Our past experience is one workflow session, one owb rt log; that was in a OWB 10.1 and ODS 10.1 scenario. Now we are in an OWB 10.1 and ODS 10.2 environment. With this many possible OWB RT Log swtiches it is difficult to perform any forensics when the system only retains 3 copies of the logs at any given time. Does anyone know where to find that parameter to up the number of logs retained? Disk space is not an issue, reasonably speaking, for possibily retaining 8 to 16 OWB RT Logs.
I can be contacted direct at [email protected]
Thank you for your help in advance.
Jeff

Hi Jeff ,
You can refer MOS note 844211.1 How To Control The Control Center Service Log Files
Thanks,
Sutirtha

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Hi!
A while ago I upgraded a 10g database to 11.2.0.2 64 Bit Windows.
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Best regards,
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lebigmac wrote:
1) Does anybody know a way of distinguishing between an automatic log switch and a manual one? Is there a table or another logfile where this information is recorded?
Off the top of my head - I think the only way to do a manual log switch is to issue "alter system switch log file", and I think that any "alter system" command is written to the alter log in you version of Oracle. (I really ought to check both statements before posting this, but I've been up since 2:30 am).
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Regards
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Checkpoint and log switch

I would like to know if when a redo log is filled, the new redo log can be written in parallel with the chekpoint.
Or simply, what's the sequence for log switching:
1 - redo log is filled -> checkpoint -> new log writes. or
2 - redo log is filled -> checkpoint/new log writes (in parallel)
Best Regards,
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null

I'm tempted to say 'don't worry about it', because L_C_T has been deprecated since 9i: instead use FAST_START_MTTR_TARGET to control the rate of checkpointing.
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A parameter does exist which will force a log switch every so often. It's called ARCHIVE_LAG_TARGET, and it's set to a number of seconds. If that was set to 1800, I could say with confidence that you'd log switch every half hour. But that's not what you had in your question, of course!
You might care to read this slightly more technical description of the parameters:
http://www.jlcomp.demon.co.uk/faq/log_checkpoint.html
(though I think Jonathan's timelines are wrong, because the change to the effect of the parameters came in with 8i).
Message was edited by:
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System PATH environment variable issue when user log off and log in or switch from admin to non-admin account

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Why PATH environment variable is not refresh immediately after log off and log in again or Switch
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loop.
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So, what's the setting for the /V: switch that your users would be using? Perhaps you should be using the ! instead of the % for your ABC variable?
Oh. There's more below where I found that...
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Hi,
I need some suggestion..
Recentry I had configured a physical standby for my 10g production database in maximum performance mode.
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Looking forward for your invaluable responce...
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Maybe you should let Oracle do it's job, configure this parameter which signifies that no buffer will remain dirty (in the cache) for more than 1800 (or whatever you want) seconds:
LOG_CHECKPOINT_TIMEOUT = 1800:p

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Dear Experts,
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Kanchana Devasurendra wrote:
Hi ARS,
Please check the following item in your new database.
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http://jonathanlewis.wordpress.com
http://www.jlcomp.demon.co.uk
A general reminder about "Forum Etiquette / Reward Points": http://forums.oracle.com/forums/ann.jspa?annID=718
If you never mark your questions as answered people will eventually decide that it's not worth trying to answer you because they will never know whether or not their answer has been of any use, or whether you even bothered to read it.
It is also important to mark answers that you thought helpful - again it lets other people know that you appreciate their help, but it also acts as a pointer for other people when they are researching the same question, moreover it means that when you mark a bad or wrong answer as helpful someone may be prompted to tell you (and the rest of the forum) what's so bad or wrong about the answer you found helpful.

Continiously log switching, one node unavailable

We run 4-node RAC 9.2.0.4 on Solaris 9. Recently, one of nodes crashed due to hardware failure. After some time since this crash, i executed the command forcing log switching within the cluster: 'Alter system archive log current'. After this command, our redo logs started switching continuously - every 5-6 seconds. Generated archived logs where almost empty - they contained only a few blocks, often only one - header, i suppose. The problem was resolved only after the thread of the died node was disabled with command 'Alter database disable thread 4;'.
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Thanks in advance
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[email protected]

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Alexey Sergeyev
[email protected]

Redo Log Switch 결과...

환경 : 8.1.7.3.0 (no archive log 모드)
log_checkpoint_timeout = 0
log_checkpoint_interval = 999999999
redo log size = 200M
현재 check point는 log switch 상태에서만 가능하도록 설정된 것 같습니다.
거래량이 적어서 그런지 log switch는 30시간 주기입니다.
제가 실행한 것은 아래 4번째 로그가 current일때
alter system checkpoint를 하고 조금 있다가..
alter system switch logfile를 하여 1번째가 current가 된 상황입니다.
3/16일 14시 까지도 계속 active상태입니다...
1. 문제가 생긴건지요??? 도움부탁합니다...
2. no archive log mode에서도 switch 주기를 줄이는 것이 복구에 도움이 되나요...?
===========================================
STATUS , FIRST_CHANGE#,FIRST_TIME
CURRENT , 8846777646687,2007-03-15 16:57:55
INACTIVE, 8846777587798,2007-03-14 10:34:40
INACTIVE, 8846777609448,2007-03-14 17:17:38
ACTIVE , 8846777643690,2007-03-15 16:01:22

no archivemode에서 정상복구를 바라는 것인지요?
잘못된 정책이란 생각이 듭니다.
no archive mode에서 v$log의 first_change# 중에 가장 작은 것
이 v$recover_file의 change# 보다 크거나 같다면 복구불능입니다.
배치작업이라도 있어서 log switch가 한번의 cycle을 돌게 되면 이전
백업으로는 복구불능입니다. archive mode로 지금 바로 바꾸시지요..
log_checkpoint_timeout은 checkpoint에 대한 timeout 시간값을
지정하는 것입니다.
LOG_CHECKPOINT_INTERVAL specifies the frequency of checkpoints in terms of the number of redo log file blocks that can exist between an incremental checkpoint and the last block written to the redo log. This number refers to physical operating system blocks, not database blocks.
checkpoint는 아시는 바와 같이 데이터파일과
리두로그 컨트롤파일의 SCN을 일치시키는 것입니다. 주요한 것은
DBWR프로세스가 데이터파일에 write를 하겠구요.
물론 checkpoint와 인스턴스 복구는 관련이 있습니다. checkpoint timeout을
적당히주면 instance recovery에서 좀 더 빠르게 instance 복구후 DB가
open되겠습니다. 만약 설정하신대로 하신다면 DB를 abort로
내리고 open하게 되면
instance recovery시에 더 많은 시간이 필요하겠습니다.
게다가 트랜잭션으로 인한 log switch하는 시간이 30시간보다
작다면 timeout을 준들 영향을 주지 않겠지요. redo log가 꽉
차게 되면 log switch를 자동으로 하게 되는데 log switch를
하기전에 checkpoint를 주게 되어 있으니까요.
그런데 checkpoint와 물리적/논리적 복구와는 다른 개념입니다.
checkpoint는 위에서 말씀드린 instance recovery와 관련이 있고
물리적/논리적 복구에서는 archive file이 떨어져 있는가 current redo log가
존재하는가에 따라서 복구가능여부를 결정되는 것이지요..
그리고 ACTIVE 상태라는 것은 문서상의 정의에서는 archive mode일 경우
archiving이 되는 중일 경우, 그리고 이 상태는 complete recovery시에 redo log
적용시 필요한 정보가 있다는 것입니다.
no archive mode에서 복구정책을 적용 하겠다는 것은 위험한 발상인 것 같습니다.
물론 DSS시스템의 경우에는 이미 정책을 no archive mode로
만들어두고 주말마다 offline backup을 하기도 합니다.
하지만 DSS에서는 하루에 300번 이상의 log switch가 일어나는
경우가 있을 정도이니 아무리 백업이 되어 있다 한들 완전복구는
불능이겠지요. offline backup을 했을 때까지만 복구가 됩니다.
$LOG
This view contains log file information from the control files.
Column Datatype Description
GROUP#
NUMBER
Log group number
THREAD#
NUMBER
Log thread number
SEQUENCE#
NUMBER
Log sequence number
BYTES
NUMBER
Size of the log (in bytes)
MEMBERS
NUMBER
Number of members in the log group
ARCHIVED
VARCHAR2(3)
Archive status (YES |NO)
STATUS
VARCHAR2(16)
Log status:
UNUSED - Online redo log has never been written to. This is the state of a redo log that was just added, or just after a RESETLOGS, when it is not the current redo log.
CURRENT - Current redo log. This implies that the redo log is active. The redo log could be open or closed.
ACTIVE - Log is active but is not the current log. It is needed for crash recovery. It may be in use for block recovery. It might or might not be archived.
CLEARING - Log is being re-created as an empty log after an ALTER DATABASE CLEAR LOGFILE statement. After the log is cleared, the status changes to UNUSED.
CLEARING_CURRENT - Current log is being cleared of a closed thread. The log can stay in this status if there is some failure in the switch such as an I/O error writing the new log header.
INACTIVE - Log is no longer needed for instance recovery. It may be in use for media recovery. It might or might not be archived.
no archive mode에서도 복구하는 여러가지 방법들이 있기는 합니다.
예를들어 current redo log가 깨졌을 때에 recovery 방법이라던지
등등이 문서에 있긴하지요. 하지만 no archivemode에서 백업을 붓고
복구하는 방법은 찾아보기 힘드실 것입니다. 위에서도 말씀드렸듯이
no archive mode에서
v$recover_file의 CHANGE# > v$logl의 minimum FIRST_CHANGE# 이면 데이터파일은 복구가능합니다.
그러나 CHANGE# <= minimum FIRST_CHANGE# 이면 복구 불가능합니
다. 그러니 백업을 붓고 복구를 하는 방법에 대한 문서는 거의
찾기 힘듭니다. advance 방법에 대한 문서에서만 adjust_scn을 쓴다던지 하는 등이 나와있을 뿐입니다.
글 수정:
민천사(민연홍)
아무래도 졸면서 썼나봅니다.;;
interval과 timeout은 엄연히 다른데요. 왜 timeout과 interval을
혼동했는지..;;
LOG_CHECKPOINT_INTERVAL specifies the frequency of checkpoints in terms of the number of redo log file blocks that can exist between an incremental checkpoint and the last block written to the redo log. This number refers to physical operating system blocks, not database blocks.
LOG_CHECKPOINT_TIMEOUT specifies (in seconds) the amount of time that has passed since the incremental checkpoint at the position where the last write to the redo log (sometimes called the tail of the log) occurred. This parameter also signifies that no buffer will remain dirty (in the cache) for more than integer seconds.

Private_strands 39 at log switch

Hi to All,
After upgrading from 8i 8.1.7.4 to 10R1 on windows 2003 sp2 we are getting this below message on every log switch when I google it I find some thing that increase the size of redo logs my 8i database redo log size is 10mb and now I increase it to 50mb but same message is coming on evry log switch.Can any body help me plz.....
"Private_strands 39 at log switch
Thread 1 advanced to log sequence 391
Current log# 1 seq# 391 mem# 0: F:\ORACLE\PRODUCT\10.1.0\ORADATA\PROS\REDO01.LOG"
Regards,
Dxb_Dba

Oracle 10g has some major changes in the mechanisms for redo (and undo), which seem to be aimed at reducing contention.
Instead of redo being recorded in real time, it can be recorded 'privately' and pumped into the redo log buffer on comit.
The message you get is related to internal Cache Redo File management.
A "strand" is new terminology for 10g and it deals with latches for redo .
Strands are a mechanism to allow multiple allocation latches for processes to write redo more efficiently in the redo buffer and is related to the log_parallelism parameter present in 9i.
The concept of a strand is to ensure that the redo generation rate for an instance is optimal and that when there is some kind of redo contention then the number of strands is dynamically adjusted to compensate.
You can disregard these messages as normal messages.
When you switch logs all private strands have to be flushed to the current log before the switch is allowed to proceed.
also refer to 372557.1 document

Want to reduce Log switch time interval !!!

Friends ,
I know that the standard LOG SWITCH TIme interval is 20/30 minutes , i.e., every time it is better switch redolog 1 to redolog 2 (or redolog2 to redolog3) within 20/30 minutes.
But in my production server , Logfile switches within every 60 minutes every time in the peak hour . Now my question , How I can make a situation where my logfile should switch to another logfile between 20/30 minutes .
Here my database configuration is :
Oracle database 10g (10.2.0.1.0 version) in AIX 5.3 server
AND
SQL> show parameter fast_start_mttr_target
NAME TYPE VALUE
fast_start_mttr_target integer 600
My every redolog file size is = 50 MB
In this situation , give me advice plz how I can reduce my logswitch time interval ?

You could either
a. Recreate your RedoLog files with a smaller size --- which action I would not recommend
OR
b. Set the instance parameter ARCHIVE_LAG_TARGET to 1800
ARCHIVE_LAG_TARGET specifies (in seconds) the duration at which a log switch would be forced, if it hasn't been done so by the online redo log file being full.
You should be able to use ALTER SYSTEM to change this value.
Hemant K Chitale
http://hemantoracledba.blogspot.com

How to get "fast user switching" and network shares playing nice

I've been alternating between banging my head against a wall and reading every forum I could find to try and get a reasonable compromise between using "Fast user switching" and sharing a folder from a file server. It baffles me how the network share/mount model of OSX/AFP is completely killed by fast-user-switching; this is a big problem with Apple requiring users to be actively logged in to share music/video from iTunes which therefore essentially requires fast-user-switching if anyone else wants to use the computer. (anyone find it odd that you can share files without being logged in, but sharing songs requires an active login for each user who is sharing? Apple: time to make iTunes sharing a service!)
For the sake of example, lets just say I want to share my /Groups folder from my desktop and have it be accessible to my laptop. Here are all the things that I tried:
Apple Method 1) Share /Groups in the Server.app on the desktop (running Lion Server), use finder on the laptop and drag the share icon to "Login Items", alternative use a startup Apple script using "mount volume" Both of the options work and will mount the /Groups folder under /Volumes/Groups, of course when the second person logs in via fast-user-switching (and occasionally the first person for no apparent reason), they will get /Volumes/Groups-1 since /Volumes/Groups is already taken. Tomorrow we log in a different order and now the previously /Volumes/Groups-1 user has their mount at /Volumes/Group and vice versa. Any links, aliases, finder sidebar references, and application settings which pointed to yesterday's location are now BROKEN. Not very user friendly to my mother-in-law who is trying to find those pictures of the kids and doesn't know anything about mount points. I also can't reasonably mirror the file location structure on the desktop so that application preferences that are synced between the two (portable home directories) work. fail.
Apple Method 2) Use automounter and set up by hand direct maps for /Groups or an indirect maps for the children of /Groups. Now it will automatically get mounted to /network/servers/SERVER/Groups/ on the laptop and on the desktop it will automatically create a similar symlink structure so that the same path (/network/servers/SERVER/Groups) work both on desktop and laptop. Cool. Except when the second person logs in, the /network/servers/SERVER/Groups/ mountpoint is already owned by the first user and they don't have any permissions to access it. Fail.
Apple Method 3) Use mount_afs and specify directly the mount-points. Have each user have their own startup AppleScript which mounts /Groups to a different location (e.g. /Users/Shared/username/Groups) that way they don't conflict with multiple users. On the desktop, set up symlinks from /Users/Shared/username/Group to /Groups so that it will be the same as the client and applications settings will work when synchronized back/forth by portable-home-directories. Will it work, yes it does, but what a bear to maintain. Is this really what I should expect to do just to have multiple users on my desktop and laptop (which again is essentially required now if I want to do any type of iTunes sharing). This can't be what apple expects.
What I ended up doing - the "not quite apple" solution.
Non-Apple Method 4) After a read of "Autofs: Automatically Mounting Network File Shares in Mac OS X" (http://images.apple.com/business/docs/Autofs.pdf) at the very end there is a single paragraph of "Kerberized NFS": "A Kerberized NFS mount can have multiple connections from multiple users, each using the correct user’s credentials for each transaction. This allows administrators to support multiple users, each authenticated with their own credentials to the same mount point. This is very different from AFP and SMB mounts," (emphasis mine)
It appears that by using good 'ole NFS (abeint with Kerberos for security!) you can actually have multiple users on the same mount point. Roughly following the guidance at https://support.apple.com/kb/TA24986?viewlocale=en_US. What I needed to do was:
1) create /etc/exports on my desktop and add a single line "/Groups -sec=krb5". The existence of /etc/exports triggered a start of nfsd which no longer has any GUI options in Lion.
2) Add a line to /etc/auto_master on my laptop "/- auto_mymounts" to reference a new direct map.
3) Create /etc/auto_mymounts and add a single line "/Groups SERVER:/Groups" to create the direct map.
THAT'S IT. Three lines in three files.
Now when I log into my laptop, there is a /Groups that is a network mount of my desktop's /Groups, same location AND it works for all of my users, even simultaneously.
In the end I'm happy with what I've got, but man was this a difficult path just to support fast-user-switching. In Lion, Apple appears to be getting away from NFS (no longer turned on by default and remove from the GUI controls) but clearly this really useful functionality which doesn't exist in AFP.
I'm really curious, after all this work. Any other ways to accomplish this?

In my example above, yes I chose to mount the share "Groups" to the top of the root since that is where I put it on my server and I wanted to keep them similar; but that was just my preference, it isn't a requirement. You can export and mount from other directories.

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