Where RFS exactly write redo data ? ( archived redo log or standby redo log ) ?

Good Morning to all ;
I am getting bit confused from oracle official link . REF_LINK : Log Apply Services
Redo data transmitted from the primary database is received by the RFS on the standby system ,
where the RFS process writes the redo data to either archived redo log files or standby redo log files.
In standby site , does rfs write redo data in any one file or both ?
Thanks in advance ..

Hi GTS,
GTS (DBA) wrote:
Primary & standby log file size should be same - this is okay.
1) what are trying to disclose about largest & smallest here ? - You are confusing.
Read: http://docs.oracle.com/cd/E11882_01/server.112/e25608/log_transport.htm#SBYDB4752
"Each standby redo log file must be at least as large as the largest redo log file in the redo log of the redo source database. For administrative ease, Oracle recommends that all redo log files in the redo log at the redo source database and the standby redo log at a redo transport destination be of the same size."
GTS (DBA) wrote:
2) what abt group members ? should be same as primary or need to add some members additionally. ?
Data Guard best practice for performance, is to create one member per each group in standby DB. on standby DB, one member per group is reasonable enough. why? to avoid write penalty; writing to more than one log files at the standby DB.
SCENARIO 1: if in your source primary DB you have 2 log member per group, in standby DB you can have 1 member per group, additionally create an extra group.
primary
standby
Member per group
2
1
Number of log group
4
5
SCENARIO 2: you can also have this scenario 2 but i will not encourage it
primary
standby
Member per group
2
2
Number of log group
4
5
GTS (DBA) wrote:
All standby redo logs of the correct size have not yet been archived.
- at this situation , can we force on standby site ? any possibilities ?
you can not force it , just size your standby redo files correctly and make sure you don not have network failure that will cause redo gap.
hope there is clarity now
Tobi

Similar Messages

The file structure online redo log, archived redo log and standby redo log

I have read some Oracle documentation for file structure and settings in Data Guard environment. But I still have some doubts. What is the best file structure or settings in Oracle 10.2.0.4 on UNIX for a data guard environment with 4 primary databases and 4 physical standby databases. Based on Oracle documents, there are 3 redo logs. They are: online redo logs, archived redo logs and standby redo logs. The basic settings are:
1. Online redo logs --- This redo log must be on Primary database and logical standby database. But it is not necessary to be on physical standby database because physical standby is not open. It doesn't generate redo log. However, if don't set up online redo log on physical standby, when primary failover and switch standby as primary. How can standby perform without online redo logs? In my standby databases, online redo logs have been set up.
2. Archived redo logs --- It is obviously that primary database, logical and physical standby database all need to have this log file being set up. Primary use it to archive log files and ship to standby. Standby use it to receive data from archived log and apply to database.
3. Standby redo logs --- In the document, it says A standby redo log is similar to an online redo log, except that a standby redo log is used to store redo data received from another database. A standby redo log is required if you want to implement: The maximum protection and maximum availability levels of data protection and Real-time apply as well as Cascaded destinations. So it seems that this standby redo log only should be set up on standby database, not on primary database. Am my understanding correct? Because I review current redo log settings on my environment, I have found that Standby redo log directory and files have been set up on both primary and standby databases. I would like to get more information and education from experts. What is the best setting or structure on primary and standby database?

FZheng:
Thanks for your input. It is clear that we need 3 type of redo logs on both databases. You answer my question.
But I have another one. In oracle ducument, it says If you have configured a standby redo log on one or more standby databases in the configuration, ensure the size of the current standby redo log file on each standby database exactly matches the size of the current online redo log file on the primary database. It says: At log switch time, if there are no available standby redo log files that match the size of the new current online redo log file on the primary database. The primary database will shut down
My current one data gurard envirnment setting is: On primary DB, online redo log group size is 512M and standby redo log group size is 500M. On the standby DB, online redo log group size is 500M and standby redo log group size is 750M.
This was setup by someone I don't know. Is this setting OK? or I should change Standby Redo Log on standby DB to 512M to exactly meatch with redo log size on primary?
Edited by: 853153 on Jun 22, 2011 9:42 AM

Online redo logs vs standby redo logs

Hi All,
Oracle version : 10.2.0.4
OS : SunOS 5.10 Generic_118855-36 i86pc i386 i86pc
This might be a silly question for the experts :(
We are having 2 standby databases and 1 logical database. Everything is running fine , I have one confusion : My primary server having 3 online redo log files and 3 standby redo log files (on primary local), but as per the architecture standby redo logs should be on standby server.My question is whether standby redo logs on standby are online redo logs of standby server or standby redo logs of primary server. e.g If i perform a log switch on primary then what is the role of sync and affirm, will lgwr write parallel on online redo logs ,standby redo logs (of primary) or online redo logs (of primary) and online redo logs (which is known as standby redo logs on standby ). Please help me to understand the scenerio.
Thanks in advance!

RFS receives redo information from the primary database.
RFS can write the redo into standby redo logs or directly to archived redo logs. Each LNSn and ARCn process from the primary database has its own RFS process.
A standby redo log is used only when the database is in the standby role to store redo data received from the primary database. Standby redo logs form a separate pool of log file groups.
Configuring standby redo log files is highly recommended on all standby databases in a Data Guard configuration, including the primary database to aid in role reversal.
A standby redo log is required to implement:
• The maximum protection and maximum availability levels of data protection
• Real-time apply
• Cascaded redo log destinations
Standby redo logs are recommended for maximum performance data protection mode. Unless you are using the real-time apply feature, standby redo logs must be archived before the data can be applied to the standby database. The standby archival operation occurs automatically.

Redo data not applied on logical standby database 10g

after a network problem within the primary and the logical standby database. The redo data is not applied on the logical standby even if all the archived log are sent to it.
The below is the output from v$archive_gap and DBA_LOGSTDBY_LOG
SQL> select * from v$archive_gap;
no rows selected
SQL> SELECT SEQUENCE#, FIRST_TIME, APPLIED
FROM DBA_LOGSTDBY_LOG
ORDER BY SEQUENCE#; 2 3
SEQUENCE# FIRST_TIME APPLIED
3937 24-FEB-10 01:48:23 CURRENT
3938 24-FEB-10 10:31:22 NO
3939 24-FEB-10 10:31:29 NO
3940 24-FEB-10 10:31:31 NO
3941 24-FEB-10 10:33:44 NO
3942 24-FEB-10 11:54:17 NO
3943 24-FEB-10 12:05:30 NO
Any help?
Thanks

ORA-00600: internal error code, arguments: [krvxgirp], [], [], [], [], [], [], []
LOGSTDBY Analyzer process P003 pid=48 OS id=8659 stopped
Wed Feb 24 16:49:04 2010
Errors in file /oracle/product/10.2.0/admin/umarket/bdump/oradb_lsp0_8651.trc:
ORA-12801: error signaled in parallel query server P003
ORA-00600: internal error code, arguments: [krvxgirp], [], [], [], [], [], [], []
and below an Warning: Apply error received: ORA-26714: User error encountered while applying. Clearing. from oradb_lsp0_8651.trc
Thanks

Dataguard lost both Primary redo log and standby redo log files

Hi,
I am new to data guard, i came acorss a scenario where we loose both primary redo log file and standby redo log files.
Can someone please help me understand how to recover from this situation.
Thanks!

>loose both primary redo log file and standby redo log files
We have to be very clear.
There are (set A) online redo log files and (set B) standby redo log files at (location 1) Primary and (location 2) Standby.
The standby redo log files, depending on the configuration, aren't strictly mandatory. The standby can be applying redo without online redo log files present as well, depending on how it was setup.
So, the question is : Did you lose online redo log files at the primary ? Didn't the primary shutdown itself then ? If so, you have to do an incomplete recovery at the primary OR switch over to the standby (which may or may not have received the last transaction, depending on how it was configured and operating) OR restore from the standby (again, with possible loss of transactions) to the primary.
Hemant K Chitale

Its working but reports ORA-16806: redo data . . .

Oracle 11g R2 Data Gauard with:
1 Primary and 2 Active Data Guard Standbys
We have it up and running and we KNOW data is being sent from Primary to each Standby.
We are querying each location once data is inserted into the Primary.
We noticed in the alert logs and when installing DG Broker that
"ORA-16806: redo data cannot be written to standby redo logs"
Can someone please explain this and possible how to correct?

Thanks for the advise . . . .
We'll start with these
11gR1 Data Guard Portal [ID 798974.1]
10gR2 Data Guard Portal [ID 739396.1]
Script to Collect Data Guard Primary Site Diagnostic Information [ID 241374.1]
Script to Collect Data Guard Physical Standby Diagnostic Information [ID 241438.1]
Steps To Create Physical Standby Database [ID 736863.1]

Standby Redo Log Files ?

Hi Everyone,
Today after reading two different sources for Standby Protection Modes i found myself puzzled and stuck. One of the article from Burleson.com says 'Oracle supports the standby redo logs on a logical standby database and can now be configured in maximum data protection modes such as MAXIMUM PROTECTION ...'
On the other hand on some of the blogs and other resources to read, i found it something opposite to what Burleson Consulting posted on their website.
[http://4.bp.blogspot.com/-t0G_-xc8EAs/Tpvx9w2t8oI/AAAAAAAAAN4/Jw3U9s89Wtk/s1600/final.JPG|http://4.bp.blogspot.com/-t0G_-xc8EAs/Tpvx9w2t8oI/AAAAAAAAAN4/Jw3U9s89Wtk/s1600/final.JPG]
or
Blog from Jeff Hunter
[http://www.idevelopment.info/data/Oracle/DBA_tips/Data_Guard/DG_3.shtml|http://www.idevelopment.info/data/Oracle/DBA_tips/Data_Guard/DG_3.shtml]
Minimum Requirements for Data Protection Modes
     Maximum Protection      Maximum Availability      Maximum Performance
Redo Archival Process      LGWR      LGWR      LGWR or ARCH
Network Transmission Mode SYNC      SYNC      ASYNC when using LGWR process. Not applicable when using ARCH process.
Disk Write Option      AFFIRM      AFFIRM      NOAFFIRM
Standby Redo Logs Required?      Yes      Required for physical standby databases only (Standby redo logs are not supported for logical standby databases.)      Required for physical standby databases using the LGWR process.
Database Type      Physical only      Physical and Logical      Physical and Logical
Please help me to find true between the two.
Or please provide any doc to read.
Thanks
Prashant Dixit

Maximum Protection Maximum Availability Maximum PerformanceDepends on Business requirement, By default Performance[most of the clients]
Redo Archival Process ? ? ?LGWR recommended in Max performance
Network Transmission Mode ? ? ?Depends. If max performance asynchronous
Disk Write Option ? ? ?Not clear
Standby Redo Logs Required? ? ? ?If real time apply - YES
Database Type ? ? ?not clear,
Assuming physical or logical? --Depends on requirement , Preferably Physical.

Standby redo log group for particular thread

hi masters,
actually i am performing an experiment to create physical standbyt database on the same machine as my primary database.
i ma going according to 'data guard admin guide'. while section for ading standby redo log group,it says that you have to add standby redo log group to "thread"....
what is this thread? and how can i foind to which thread i have to assign the next redo log group??
how can i find current thread??
what if i dont add "to thread' clause in my statement:-
ALTER DATABASE ADD STANDBY LOGFILE THREAD 5
2> ('/oracle/dbs/log1c.rdo','/oracle/dbs/log2c.rdo') SIZE 500M;
thanks and regards
VD

Vikrant,
First a question: Do you have a RAC instance? If so the paragraph even doesn't apply to you and I'm not sure why you are questioning it.
Secondly
"The THREAD clause is required only if you want to add one or more standby redo log
file groups to a specific primary database thread. If you do not include the THREAD
clause and the configuration uses Real Application Clusters (RAC), Data Guard will
automatically assign standby redo log file groups to threads at runtime as they are
needed by the various RAC instances."
this means you dont have to specify thread for RAC,as it will allocate one according to current thread.
Your conclusion is incorrect.
Where do you read the word 'current'?
Oracle will likely simply make sure each instance has sufficient standby redolog groups, the requirement is 1 standby redolog group per group + 1 extra.
Sybrand Bakker
Senior Oracle DBA

Ok, so I want to buy the new iPod touch 5g this week and I have an iPhone 4. I want to transfer all the data from the phone to the iPod and have the files the exact same. I don't want to redo data, say erase game data (campaigns, achievements)...

Ok, so I want to buy the new iPod touch 5g this week and I have an iPhone 4. I want to transfer all the data from the iPhone to the iPod and have the files the exact same. I don't want to redo data, say erase game data (campaigns, achievements)... I have apps that have very important data on them and if I sync it to iTunes and then transfer all that data to the iPod Touch 5g, will that erase app data?

iOS: Transferring information from your current iPhone, iPad, or iPod touch to a new device

Redo and archive log association

Hi,
I am curious about the redo file and archive log file association, is it one to one, or one to many? That is, does one arc log file hold data from just one redo file or many redo files?
Or , is the association redo group to arc file as opposed to redo file to arc file?
The size of the arc log files on my machine, sometimes far exceeds the size of a single redo file and sometimes goes well under the size.
Thanks.

I am curious about the redo file and archive log file association, is it one to one, or one to many?One archive log file represents one redo log file contents in a group.You can have multiple logfile members in a group. All the members have the same data.
The size of the arc log files on my machine, sometimes far exceeds the size of a single redo file and sometimes goes well under the size.The size of the archive log can be smaller from redo logfile in following scenarios:--
1. Manual log switch.
2. Setting archive_lag_target parameter.
sometimes far exceeds the size of a single redo file I am not very sure about it.I haven't seen size greater than the redo logfile.
Anand
Edited by: Anand... on Sep 2, 2009 7:45 PM

GoldenGate : Why to read all the Redo or Archive, can't we skip ??

Hi All,
I have a big doubt if anyone can give clarity. The scenario is :- In my environment data is flowing from Oracle to Oracle but Huge transactions in Millions and we use this tool basically to improve LAG when we get data for reporting.
Now let's say I have database user A which is doing some temporary transaction on source for couple of hours but it is HUGE and generating lot of archives AND we don't want to flow any data from the transaction being performed by user A - so we use EXCLUDEUSER A parameter.
Now during same time if any other user say B is performing some operation in one table - we want it to flow, So it is flowing normally BUT the main problem is LAG increased like anything cause GoldenGate is now reading all the redo or archives which of no use and data is flowing very slowly :( :(
My point was will it be also possible that I don't want my GoldenGate to read any redo log or archives if the user A is performing operation and read only those archives if user B or any other user is performing some operation. This will improve the LAG cause even though we ignore the particular user, It is still going to read all the redo or huge archives generated by user A or user B or whatever in sequence, Please correct me if I am wrong ?
I suppose goldengate is going to read all the transaction regardless of A or B user. Only it will ignore the A and process transaction of B.
I know it reads in sequence but can't it read specific archives which is useful instead of reading all.

Hi Steven,
Thanks for your reply.
I agree with you that "normal" mode of GoldenGate is to capture changes and replicate them and Ofcourse I want it to capture any changes but I don't want it to pass through reading all the archives if I am ignoring one user who is performing HUGE temporary transaction and generating huge archives.
It is going to slow down all the other small transaction changes cause it is passing through all those archives also which is of NO use. Do you mean that "Integrated mode" of new Goldengate version will work in that case ?
Please help, I really need this information. It will help everyone.

Compressing redo data for Physical Standby

Hi All,
I have been checking option of compressing redo data for a Physical Standby database. I did not find many details in the docs. Any one has implemented this kind of compression.
Cheers/Aditya

per Oracle support, redo compression in DG makes sense only if the bandwidth between the primary & standby server is less than 100mbps and is expected to be heavily taxing on CPU.
you may check metalink article ID: 729551.1 where they have given some test stats. Not a whole lot of data, but it might help you make a good judgement.
Cheers.

Data archiving for Write Optimized DSO

Hi Gurus,
I am trying to archive data in Write Optimized DSO.
Its allowing me to archive on request basis but it archives entire requests in the DSO(Means all data).
But i want to select to archive from this request to this request.(Selection of request by my own).
Please guide me.
I got the below details from SDN.Kindly check.
Archiving for Write optimized DSOs follow request based archiving as opposed to time slice archiving in standard DSO. This means that partial request activation is not possible; only complete requests have to be archived.
Characteristic for Time Slice can be a time characteristic present in the WDSO, or the request creation data/request loading date. You are not allowed to add additional infoobjects for semantic groups, default is 0REQUEST & 0DATAPAKID.
The actual process of archiving remains the same i.e
Create a Data Archiving Process
Create and schedule archiving requests
Restore archiving requests (optional)
Regards,
kiruthika

Hi,
Please check the below OSS Note :
http://www.sdn.sap.com/irj/servlet/prt/portal/prtroot/com.sap.km.cm.docs/oss_notes/sdn_oss_bw_whm/~form/handler%7b5f4150503d3030323030363832353030303030303031393732265f4556454e543d444953504c4159265f4e4e554d3d31313338303830%7d
-Vikram

Archive all the active online redo logs

Hi,
in 9.2.0 and in archivelog mode, how can I archive all the active online redo logs ?
Thank you.

Is ur database already running in archivelog mode?? If yes and if automatic archiving is enabled then ur redo will be archived automatically. I think first you need to check whether ur DB is in archive log mode or not?? Post the output of (from sqlplus):
archive log list
Daljit Singh

Data Guard : Standby Redo Log CONFUSION

Trying to set up test Standby db on 10.2.0
I am well confused about below step 3.1.3, how is the normal redo linked with standby redo, should standby not be members of orginal redo groups?
http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/create_ps.htm#i1225703
Original redo logs:
SQL> select * from v$log;
    GROUP#    THREAD# SEQUENCE#      BYTES    MEMBERS ARC STATUS           FIRST_CHANGE# FIRST_TIME
         1          1         28   52428800          1 YES INACTIVE                375136 22-NOV-07
         2          1         29   52428800          1 YES INACTIVE                375138 22-NOV-07
         3          1         30   52428800          1 NO CURRENT                 375143 22-NOV-07I added below from notes:
ALTER DATABASE ADD STANDBY LOGFILE GROUP 10
('/u01/oracle/oradata/db01/redo01_stb.log') SIZE 50M;
ALTER DATABASE ADD STANDBY LOGFILE GROUP 11
('/u02/oracle/oradata/db01/redo02_stb.log') SIZE 50M;
ALTER DATABASE ADD STANDBY LOGFILE GROUP 12
('/u03/oracle/oradata/db01/redo03_stb.log') SIZE 50M;After few alter system switch logfile; I still have:
    GROUP#    THREAD# SEQUENCE# ARC STATUS
        10          0          0 YES UNASSIGNED
        11          0          0 YES UNASSIGNED
        12          0          0 YES UNASSIGNEDAll are UNASSIGNED, should one standby group not be ACTIVE like the above link shows.
Many think for any help

First things first:
From the Docs.:
"Minimally, the configuration should have one more standby redo log file group than the number of online redo log file groups on the primary database. However, the recommended number of standby redo log file groups is dependent on the number of threads on the primary database. Use the following equation to determine an appropriate number of standby redo log file groups:
(maximum number of logfiles for each thread + 1) * maximum number of threads
Using this equation reduces the likelihood that the primary instance's log writer (LGWR) process will be blocked because a standby redo log file cannot be allocated on the standby database. For example, if the primary database has 2 log files for each thread and 2 threads, then 6 standby redo log file groups are needed on the standby database."
You are 1 short!

Where RFS exactly write redo data ? ( archived redo log or standby redo log ) ?

Similar Messages

Maybe you are looking for