Dataguard DR Standby

Hi,
I need some advice on whats the best practice to implement a DR using Dataguard. I noticed most DR are using a primary and standby concept. I am looking into having one primary with two standby whereby standby A will come up if Primary is down and standby B only if standby A doesn't work. Any suggestion and pointers, if this should be done or just single standby?

Hello Bala,
I am looking into having one primary with two standby whereby standby A will come up if Primary is down and standby B only if standby A doesn't work. Any suggestion and pointers, if this should be done or just single standby?
Well you are asking the wrong question at the wrong time.
The first question should be: Is there any business case that requires two standby databases like having 3 different data centers (one for primary and two different ones for the standby databases)?
If the answer is yes - then you should think about the implementation concept like SYNC or UN-SYNC mirror which requires different bandwith and implementations. SYNC mirror will affect the performance more and more with every additional standby database. Maybe it is sufficient to run only one in SYNC and one in UN-SYNC mode.
Having two standby databases just for the reason if one fails to have another one is not reasonable, because of if standby A fails its mostly because of a configuration issue or bug and in that cases both standby databases will have the same problem.
If you want multiple standby databases - i would highly recommend to use Oracle Data Guard Broker for managing this environment, because of it is getting more and more complex with every standby database by a Switch-/Failover.
If you want to get an idea of the performance impact - please check this "Best Practices" whitepaper:
http://www.oracle.com/technetwork/database/features/availability/maa-wp-10gr2-dataguardnetworkbestpr-134557.pdf
Regards
Stefan

Similar Messages

Is Dataguard and standby dbs is HA

Hi
is Dataguard and standby dbs is HA or RAC is the only oracle HA?
is Dataguard is only DR?
Thanks

RAC and DATAGAURD are two different approches for high availability and desaster recovery.
We are planning to implememt RAC and DATAGAURD but there are budget issues also.
With RAC As i understand we have multiple instances governing a single database. So multiple node/machines governing a single database server.
With DATAGAURD,we have a DR solution at another location.If the primary server fails,standby database takes up the role of primary.
With RAC alone,if any node fails, there is another node to do instance recovery or the server still continues. But what if database server crashes. WIth RAC alone and no dataguard, won't it allow downtime?

Oracle DataGuard Logical Standby

Hi , I'd like to know what are the premisses to make a standby logical replication.
I have two environments (production and standby) with different number of processors and storage.
I'd like to know if it's possible to create data guard solution with these two environments and what are the premisses that I need aware to install the solution.
Thanks in advance.

Hello;
Yes the storage ( as long as you have enough space ) and cpu don't matter.
You can use hardware that's quite a bit different and it will work fine.
You can also create a Logical Standby fro a physical standby.
These notes may help :
NOTE 413484.1 - Data Guard Support for Heterogeneous Primary and Physical Standbys in Same Data Guard Configuration
Mixed Oracle Version support with Data Guard Redo Transport Services [ID 785347.1]
Logical Standby's don't seem to be very popular and the support base suffers because of this. I would consider a physical standby with Active Data Guard if costs allow.
Active Data Guard makes an excellent "Reader" database plus I believe your switchover and failover options are much better than a Logical Standby.
Oracle DataGuard Logical Standby Setup :
http://orajourn.blogspot.com/2007/02/setting-up-logical-standby-database.html
http://garyzhu.net/notes/DataGuard.html
Best Regards
mseberg
Edited by: mseberg on Apr 25, 2012 10:07 AM

11gr2 Dataguard Active Standby - Unable to get Real-Time apply working

As above, I am unable to get real time apply to work WITHOUT it switching my standby back to MOUNT state. There does not seem to be anyting obvious from the broker, or alert logs.
On the Standby:
SQL> alter database recover managed standby database cancel;
Database altered.
SQL> alter database open read only;
Database altered.
SQL> select open_mode from v$database;
OPEN_MODE
READ ONLY
SQL> alter database recover managed standby database using current logfile disconnect;
Database altered.
SQL> select open_mode from v$database;
OPEN_MODE
MOUNTED
Primary:-
SQL> SELECT status, recovery_mode FROM v$archive_dest_status where dest_name = 'LOG_ARCHIVE_DEST_2';
STATUS RECOVERY_MODE
VALID MANAGED REAL TIME APPLY
Edited by: Imran on Apr 17, 2012 10:56 PM

Hello;
This is expected.
Works the same exact way on my system. How Redo Data is applied is set when the database is MOUNTED.
See - 6 Redo Apply Services
Data Guard Concepts and Administration 11g Release 2 (11.2) E10700-0
The document is vague on this at best, but think about the error you get if you try to start apply twice.
Data Guard Real-Time Apply FAQ [ID 828274.1]
Best Regards
mseberg
Edited by: mseberg on Apr 17, 2012 10:04 AM
h1. Test
Connected to:
Oracle Database 11g Enterprise Edition Release 11.2.0.2.0 - 64bit Production
With the Partitioning, OLAP, Data Mining and Real Application Testing options
SQL> alter database recover managed standby database cancel;
Database altered.
SQL> alter database open read only;
Database altered.
SQL> alter database recover managed standby database using current logfile disconnect;
Database altered.
SQL> select open_mode from v$database;
OPEN_MODE
READ ONLY WITH APPLY
SQL> So I get different results ??
Edited by: mseberg on Apr 17, 2012 10:40 AM
h2. Still more
I would like to change my answer. Based on my test and queries as shown below I believe REAL TIME apply is working. Note the last log says NO because its in progress.
Checking last sequence in v$archived_log
STANDBY               SEQUENCE# APPLIED    COMPLETIO
STANDBY                     343 YES        16-APR-12
STANDBY                     344 YES        16-APR-12
STANDBY                     345 YES        16-APR-12
STANDBY                     346 YES        16-APR-12
STANDBY                     347 YES        17-APR-12
STANDBY                     348 NO         17-APR-12
6 rows selected.
----------------Last log on Primary--------------------------------------|
MAX(SEQUENCE#)
           348
1 row selected.Yes, I doubled check and it works on mine. I guess I read what I wanted to read.
All my Standby redo are setup correctly ( size and numbers )
READ ONLY WITH APPLYYour answer my be the Uwe answer at the end of this thread :
Enabling the Active Dataguard and Real Time Apply
Best Regards
mseberg
Edited by: mseberg on Apr 17, 2012 10:50 AM

Dataguard logical standby issue on lacking

we have logical standby database and its has been lacking sql apply from 14 hrs from primary database. Is there anyway i can stop sql apply and recover the database through archive files and make sync with primary and then again start the sql apply on logical standby database.
Please adivce

Neon,
I won't respond any further. The Dataguard Concepts and Administration Manual does contain a section on Troubleshooting.
It is quite clear you are using technology on which you have insufficient knowledge.
However, you belong to the class of wannabe-DBAs here,who as soon as they run into trouble start posting doc questions labeled with
'I need the detail steps'
'Urgent'
or (new development) post
'Any help' every half hour, when a volunteer didn't respond to their question.
If you want a quick response, submit a SR at Metalink. At least those analists are getting paid to answer your doc questions.
Sybrand Bakker
Senior Oracle DBA

ORACLE DATAGUARD and STANDBY on two LINUX machine (64 bits and 32 bits)

Hi there
I have two Linux machines: one with Linux RH 4 Update 2 for 64 bits and
the other one with Linux RH 4 Update 2 for 32 bits.
I was wondering two things:
1) Is it possible to implement ORACLE DATAGUARD between these two machines?
2) Is it possible to implement only a Static Standby Database on the second node?
Suppose we have Oracle Database EE on both machines.
Thanks in advance for any information
Regards
Felipe

But both oracle database version must be of 32 bit version.
from oracle doc
2.3.1 Hardware and Operating System Requirements
The following list describes hardware and operating system requirements for using Data Guard:
All members of a Data Guard configuration must run an Oracle image that is built for the same platform.
For example, this means a Data Guard configuration with a primary database on a 32-bit Linux on Intel system can have a standby database that is configured on a 32-bit Linux on Intel system. However, a primary database on a 64-bit HP-UX system can also be configured with a standby database on a 32-bit HP-UX system, as long as both servers are running 32-bit images.

Oracle 10g Dataguard Physical Standby Database

When I set my dataguard group to "MAXIMIZE AVAILABILITY" the protection level is always RESYNCHRONIZATION.
It's normal ?
SQL> SELECT PROTECTION_MODE, PROTECTION_LEVEL, DATABASE_ROLE FROM V$DATABASE;
PROTECTION_MODE PROTECTION_LEVEL DATABASE_ROLE
MAXIMUM AVAILABILITY RESYNCHRONIZATION PHYSICAL STANDBY
SQL> show parameter log_archive_dest_2
NAME TYPE VALUE
log_archive_dest_2 string SERVICE=PIJ10G2 LGWR SYNC AFFIRM
SQL> show parameter log_archive_dest_state_2;
NAME TYPE VALUE
log_archive_dest_state_2 string ENABLE

this is my log on primary db :
Thread 1 advanced to log sequence 422
Current log# 1 seq# 422 mem# 0: /oradata/orapij10g/redologs/PIJ10G/redo01.log
Wed Oct 1Thread 1 cannot allocate new log, sequence 423
Private strand flush not complete
Current log# 1 seq# 422 mem# 0: /oradata/orapij10g/redologs/PIJ10G/redo01.log
Wed Oct 17 16:24:51 2007
Destination LOG_ARCHIVE_DEST_3 is SYNCHRONIZED
LNSc started with pid=34, OS id=21052
Wed Oct 17 16:24:56 2007
Destination LOG_ARCHIVE_DEST_3 is UNSYNCHRONIZED
Wed Oct 17 16:24:56 2007
Errors in file /oracle/ora10g/admin/PIJ10G/bdump/pij10g_lgwr_26248.trc:
ORA-16086: Message 16086 not found; No message file for product=RDBMS, facility=ORA
LGWR: Failed to archive log 2 thread 1 sequence 423 (16086)
Thread 1 advanced to log sequence 423
Current log# 2 seq# 423 mem# 0: /oradata/orapij10g/redologs/PIJ10G/redo02.log
I don't understand this error message. How can solve my probleme ?

Dataguard Vs Standby

Hi All,
I know most of you have experienced in production implem of standby and dataguard. For me I only done it on test theory and not yet on production becuase
it generats lots of logs and also affects performance.
Also For me I only do shutdown and copy the files to another disk since we can afford to shutdown the database after office hours.
I have not considered that the database can crash anytime of the day and I will lose transactions of the day.
But how do you protect your database which is in archivelog mode when the disk itelf where the logs resides get crashed and gets irrecoverable.
And the even the reduntant copy of redo are also located on the same raid disk?
What did you do when sometimes it happens the one of the archivelogs is missing or has 0 bytes size (meaning got corrupted)?
Thanks a lot,
Yxz

Hi all,
I can only afford to setup standby as I do not have money to buy dataguard :(
Please can you enlighten me how can I recover my standby if my source database crashed and not recoverable anymore, like theres a bomb explode in my prod server while production is going on.
So there have been archive logs which lately committed and are current that is not yet transferred to the standby site. And I wonder how dataguard be able to address this?
Thanks a lot,

RAC & DataGuard (Physical Standby)

Hello all,
I'm trying to get a high level overview of how RAC & DataGuard would behave in the following configuration. I've written down my understanding of how things would work. Please correct me if I'm wrong.
1) 2 node RAC (Primary Database) with a single instance physical standby.
a) Same standby related init.ora parameters would have to configured on both primary rac nodes.
b) The redo apply service at the standby would merge the redo from the 2 threads from the primary and apply it to the standby to keep it in sync.
c) During switch over only one primary RAC instance should be up besides the standby instance.
d) During switch back again only one primary RAC instance should be up besides the standby instance.
e) During failover ofcourse both primary instances would be down which warrants the fail over.
2) 2 node RAC (Primary) with a 2 node physical standby
This where it gets complex and I'm not really sure how a,b,c,d,e would be in this scenario. Appreciate if you could shed some light on this and list what
a,b,c,d,e would look like in this scenario.
I'm assuming that only one instance in the standby RAC should be up when the standby is in RAC configuration for the redo apply to work.
Also, if there is a white paper that details step by step procedure for setting up the above 2 scenarios, please let me know. So far I was able to find only the MAA white paper but that was not very helpful. If you can prescribe a good book for RAC & DataGuard that would be great too..
Thanks for your help

>
1) 2 node RAC (Primary Database) with a single instance physical standby.
a) Same standby related init.ora parameters would have to configured on both primary rac nodes.Usually rac nodes share their spfile on a shared diskvolume or through ASM. So they have identical DG parameter anyway
b) The redo apply service at the standby would merge the redo from the 2 threads from the primary and apply it to the standby to keep it in sync.Correct
c) During switch over only one primary RAC instance should be up besides the standby instance.
Sounds logical to me
Edit: In fact during normal operation both RAC nodes are up, so during switchover they are both active too
It is the configuration that matters. As soon as the standby is becoming primary, it might be that it talks only to one RAC node for its log-apply files
d) During switch back again only one primary RAC instance should be up besides the standby instance.That single was the only one running in step c.
e) During failover ofcourse both primary instances would be down which warrants the fail over.Correct. Keep in mind that during a failover the RAC config would be deconfigured from the DG setup and has to be added back again as standby.
You might have to take a look at: http://www.oracle.com/technology/deploy/availability/pdf/MAA_WP_10g_RACPrimarySingleInstancePhysicalStandby.pdf
>
2) 2 node RAC (Primary) with a 2 node physical standby
This where it gets complex and I'm not really sure how a,b,c,d,e would be in this scenario. Appreciate if you could shed some light on this and list what
a,b,c,d,e would look like in this scenario.
I'm assuming that only one instance in the standby RAC should be up when the standby is in RAC configuration for the redo apply to work.
No. RAC primary to RAC Standby would mean both nodes are up on both side. PrimNode1 send its redo logs to StandbyNode1 and the same for PrimNode2 and StandbyNode2
Have a look here: http://www.oracle.com/technology/deploy/availability/pdf/MAA_WP_10g_RACPrimaryRACPhysicalStandby.pdf
HTH,
FJFranken
My Blog: http://managingoracle.blogspot.com
Edited by: fjfranken on 16-jul-2010 1:13

Rman duplicate on Active dataguard physical standby

In DR site. i have to clone the database from pshysical standby database and clone db will be normal db not standby. Is it possible to do rman duplicate from active dataguard? will it support the duplicate database from active database or i have to take the rman backup of standby database and duplicate from backup piece. please advise

Please check below link
http://odenysenko.wordpress.com/2012/03/26/rman-duplicate-from-active-database-from-standby-ends-with-ora-01671/
Hope this answers all your questions,
Regards,
http://www.oracleracexpert.com
ORA-01031: insufficient privileges
http://www.oracleracexpert.com/2013/02/ora-01031-insufficient-privileges.html
Error while loading shared libraries: libdb.so.2 - After Migrating REHL4 to REHL5
http://www.oracleracexpert.com/2013/01/error-while-loading-shared-libraries.html

Dataguard physical standby archive log question

Hi all,
I will try to keep this simple..
I have a 4 node RAC primary shipping logs to a 2 node physical standby.
On the primary when I run 'alter system archive log current' on an instance I only see 1 log being applied on the standby, that is by querying v$archived_log.
If I run the following on the standby:
select thread#,sequence#,substr(name,43,70)"NAME",registrar,applied,status,first_time from v$archived_log where first_time
in
(select max(first_time) from v$archived_log group by thread#)
order by thread#
I get:
THREAD# SEQUENCE# NAME REGISTR APPLIED S FIRST_TIME
1 602 thread_1_seq_602.2603.721918617 RFS YES A 17-jun-2010 12:56:58
2 314 thread_2_seq_314.2609.721918627 RFS NO A 17-jun-2010 12:56:59
3 311 thread_3_seq_311.2604.721918621 RFS NO A 17-jun-2010 12:57:00
4 319 thread_4_seq_319.2606.721918625 RFS NO A 17-jun-2010 12:57:00
Why do we only see the max(sequence#) having been applied and not all of them?
This is the same no matter how many times I archive the current log files on any of the instances on the primary and also the standby does not have any gaps.
Hope this is clear..
any ideas?
jd

ok output from gv$archived_log on standby BEFORE 'alter system archive log current' on primary
THREAD# SEQUENCE# NAME REGISTR APPLIED S FIRST_TIME
1 679 thread_1_seq_679.1267.722001505 RFS NO A 18-jun-2010 11:58:22
1 679 thread_1_seq_679.1267.722001505 RFS NO A 18-jun-2010 11:58:22
2 390 thread_2_seq_390.1314.722001507 RFS NO A 18-jun-2010 11:58:23
2 390 thread_2_seq_390.1314.722001507 RFS NO A 18-jun-2010 11:58:23
3 386 thread_3_seq_386.1266.722001505 RFS YES A 18-jun-2010 11:58:22
3 386 thread_3_seq_386.1266.722001505 RFS YES A 18-jun-2010 11:58:22
4 393 thread_4_seq_393.1269.722001507 RFS NO A 18-jun-2010 11:58:23
4 393 thread_4_seq_393.1269.722001507 RFS NO A 18-jun-2010 11:58:23
Output from v$archived_log on standby AFTER 'alter system archive log current' on primary
THREAD# SEQUENCE# NAME REGISTR APPLIED S FIRST_TIME
1 680 thread_1_seq_680.1333.722004227 RFS NO A 18-jun-2010 11:58:29
1 680 thread_1_seq_680.1333.722004227 RFS NO A 18-jun-2010 11:58:29
2 391 thread_2_seq_391.1332.722004227 RFS NO A 18-jun-2010 11:58:30
2 391 thread_2_seq_391.1332.722004227 RFS NO A 18-jun-2010 11:58:30
3 387 thread_3_seq_387.1271.722004225 RFS NO A 18-jun-2010 11:58:28
3 387 thread_3_seq_387.1271.722004225 RFS NO A 18-jun-2010 11:58:28
4 394 thread_4_seq_394.1270.722004225 RFS YES A 18-jun-2010 11:58:29
4 394 thread_4_seq_394.1270.722004225 RFS YES A 18-jun-2010 11:58:29
as a reminder we have a 4 node RAC system shipping logs to a 2 node RAC standby. There are no gaps but only one log is ever registered as being applied.
Why is that? Why arnt all logs registered as being applied?

Dataguard - logical standby - need help - not updating data at commit

Hi
Need help ?
We have logical standby setup where data is not updated at standby when committed at Primary. It only updates when alter system swith logfile.
On Primary:
log_archive_dest_2='service=xxStandby LGWR ASYNC valid_for=(online_logfiles,primary_role) db_unique_name=xxStandby'
On Standby:
we have already created standby redo logs ( 1+ # redo logs)
we used ALTER DATABASE START LOGICAL STANDBY APPLY IMMEDIATE NODELAY;
The data only ships when we do the ALTER SYSTEM SWITCH LOGFILE whereas it should so when data is commited on the primary.
Is there anything we are missing or need attention.
Please help
Thanks you so much

Yes, I have standby redo logs = ( 1 + # redo logs on the primary) and are of same size.
I also changed the log_archive_dest_2 setting for valid_for to ALL_LOGFILES, but the performance is still very slow... we are now overr 9 hrs behind the primary.
log_archive_dest_2='service=xxStandby LGWR ASYNC valid_for=(ALL_LOGFILES,primary_role) db_unique_name=xxStandby'
The Logical standby performance reallly not good at all. trying to increase sga/pga more ... hoping this will speed up some
Paul

Dataguard Logical Standby

Question: We're just thinking here.
If I have a primary database (A), which has a logical standby database (B), is it possible to have a logical standby database (C) for database (B)?
We have users that are updating tables in the logical standby database (B) but these are different tables than what are being updated from primary database (A).
Thank you

Yes.
http://download.oracle.com/docs/cd/B19306_01/server.102/b14239/cascade_appx.htm#i636960

DataGuard ? Standby (Logical/Physical) ? Need Information - Implementations

Hi All
I am trying to aquaint my self with the DataGuard concepts but I must admit I have limited knowledge/exposure into this side... when I have set-up the DR so as to ship archives from the primary to disaster recovery site geographically located else where.. and that was in oracle 9i 9.2.x release..
Now there is 10g and then 11g.. and as I learn DR has evolved alot in its implementation methodologies. I am trying to fid an anecdote which can talk in a little detail/more detail but some detail less than the oracle documentation it self would be..
Honestly, when I pulled out the pdf's, I could not proceed much length... and am coming here.. for your help...
hoping may be one of you, if not most of you might have explored it well already ad might have recorded it some where in your content. If you would not mind, could you please let me know where I can get such info and then ofcourse, understand it better and quicker!!
Thanks!
Sarat

Hi All
I am trying to aquaint my self with the DataGuard concepts but I must admit I have limited knowledge/exposure into this side... when I have set-up the DR so as to ship archives from the primary to disaster recovery site geographically located else where.. and that was in oracle 9i 9.2.x release..
Now there is 10g and then 11g.. and as I learn DR has evolved alot in its implementation methodologies. I am trying to fid an anecdote which can talk in a little detail/more detail but some detail less than the oracle documentation it self would be..
Honestly, when I pulled out the pdf's, I could not proceed much length... and am coming here.. for your help...
hoping may be one of you, if not most of you might have explored it well already ad might have recorded it some where in your content. If you would not mind, could you please let me know where I can get such info and then ofcourse, understand it better and quicker!!
I think to be DBA one must have patience and determination. You have to go through the document, then try yourself if anything is not in documentation and you face some problem then come to us. I got a very good link from oracle corporation. This is divided into topics, you can go one by one and ask quetions in the forum if you feel like. Check this
Regards.

Table created in Dataguard and standby

Hi,
in a DATAGUARD_STANDBY configuration, if I create a table in primary DB, will I see it in STANDBY ? How many times after ?
What are the parameteres that detemine the time interval ?
Many thanks.

Yes like Werner mentioned the Data Protection Mode of Data Guard.
Just to post a link for you to study,
Choosing a Data Protection Mode
For example, if you have Maximum Protection Mode
Each transaction must be written to both the local online redo log and to the standby redo log on at least one standby database before the transaction commits. For this you need to set LGWR, SYNC on the LOG_ARCHIVE_DEST_n parameter.
DDL is not technically a 'transaction' however internally Oracle need to commit the change in data dictionary which will instantly available on Standby server if you on this mode.

Dataguard DR Standby

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