Database Software

Hello;

Emre Baransel has Switchover Notes and Failover Notes for Rac here:

http://emrebaransel.blogspot.com/2010/12/dataguard.html

It's well down the page, search for "Switchover Notes"

Best Regards

mseberg

Do you have the DG Broker setup and running? If so, then you can easily do the swithcover/failover in the Broker with one command. The Broker is RAC-aware.

If you want to do this in EM, then you'll need the DG Broker. All EM does is issue commands to the Broker for you.

Cheers,
Brian

 We have 2 node RAC and 2 node DATAGUARD Physical standby database and dataguard broker is enabled. I have following questions.

When the dataguard is managed by the BROKER, you shouldn't be opting to do the switchover/failover manually using SQL. Perform the tasks using the broker.

HTH http://www.oracledba.org/11gR2/dr/11gR2_dataguard_RAC_to_RAC.html

-- Shivananda Rao

Hi,

We have 2 node RAC and 2 node DATAGUARD Physical standby database and dataguard broker is enabled. I have following questions.
1)What are the steps to do Switchover/Failover operation manually in 2-node RAC and 2-node DATAGUARD environment.

1. First thing, if you refer to oracle documentation, switchover and failover is done with single instance all the time never done or carried with more than one instance up and running.

2. You need to shutdown all instances except one instance up and running on Primary and Standby

3. It's not mandatory that you must do with broker only, as per your wish you can disable the broker and you can perform manual switchover or failover (else being utilized broker you can perform using DG Broker)

4. Coming to steps its very well documented in Oracle Documentation

Broker : http://docs.oracle.com/cd/B28359_01/server.111/b28295/cli.htm#i1007698   (scenarios documented given by oracle itself)

5. You can refer to google for further demos you will get it

DATAGUARD SWITCHOVER GUIDE (PHYSICAL STANBY)

http://www.datadisk.co.uk/html_docs/oracle_dg/switchover_failover.htm

Note -- Remember every where the steps would be same-- which are documented in oracle documentation that is first source of truth to learn from it

2) Switchover/Failover option is disabled on Enterprise Manager.What are the steps to enable it so that I can do Switchover/Failover operation using OEM.

http://www.oracle.com/technetwork/articles/oem/havewala-odg-oem12c-1999410.html

You have documentation you need to refer to that

-Hope it helps

- Pavan Kumar N

Hi Pavan,

Thanks for your reply.

I did not get your point no.2 "You need to shutdown all instances except one instance up and running on Primary and Standby"  in your reply.

can you please explain it with following scenarios

1)Primary database - 2 node

Instance names are

instance1 = rac01-primary 

instance 2= rac02-primary

2)physical standby db- 2 node

Instance names are

instance1 = rac01-stby 

instance 2= rac02-stby

Regards,

Narottam

can you please explain it with following scenarios
1)Primary database - 2 node 
Instance names are
instance1 = rac01-primary  
instance 2= rac02-primary 
2)physical standby  db- 2 node
Instance names are
instance1 = rac01-stby  
instance 2= rac02-stby 

Thank you for coming back with questions.

1. You need have only one instance up and running among rac01-primary  or rac02-primary  while performng switchover or failover. You can't have both instances up and running in order to achieve or perform switchover task.

Since its exclusive must carried out.

2 . Similarly on DR you have one instance up and running rac01-stby  or rac02-stby (since people use both DR instances for recovery some times).

I did not get your point no.2 "You need to shutdown all instances except one instance up and running on Primary and Standby"  in your reply.
can you please explain it with following scenarios
1)Primary database - 2 node
Instance names are
instance1 = rac01-primary 
instance 2= rac02-primary
2)physical standby db- 2 node
Instance names are
instance1 = rac01-stby 
instance 2= rac02-stby

While performing switchover, all instances of primary should be down except one instance. Similarly, on the standby, all the instances should be down except one instance.

It needs to be performed as if you are working on a single instance primary with a single instance standby.

I guess you haven't gone through the links provided to you. Just to help you out, posting the link again

11gR2 RAC to RAC Dataguard with Dataguard Broker MAA

HTH

-- Shivananda Rao

Hi Shivanand and Pavan,

1)  Please tell me post switchover steps.

11gR2 RAC to RAC Dataguard with Dataguard Broker MAA

From above steps I came to know that, I need to start other db instances on both primary and standby.

What are the other steps which I need to follow after starting all instances.

  Please tell me post switchover steps.

2)Once first switchover is completed, I want to do one more switchover to bring both db at their own state.

Regards,

Narottam

Oracle Database --- Tips and Best Practices: SWITCHOVER STEPS FOR RAC PHYSICAL STANDBY :-

http://gavinsoorma.com/2010/03/11g-data-guard-broker-dgmgrl-configuration-quick-steps/

Good luck

mseberg

Hi,

1. Post switchover it would like standby becomes primary and primary becomes standby. Now if you want to  switchover once again (that is swtich back) you need to perform the same steps as you did earlier.

2. Make sure logs transfers over to new standby.

3. Check listener and tns entries and check for log_Archive_Dest parameters

4. Make sure you are logs able to apply on standby

5. Now continue with switchover steps as you performed earlier. If switchover then logically new primary becomes standby and vice versa

- Pavan Kumar N

1. First thing, if you refer to oracle documentation, switchover and failover is done with single instance all the time never done or carried with more than one instance up and running.
2. You need to shutdown all instances except one instance up and running on Primary and Standby

If you use the DG Broker, then you can leave all instances up and running. Launch dgmgrl and issue the switchover command. The DG Broker will handle multiple instances just fine.

Cheers,

Brian

Hi,

From 10.2, if you perform switchover through broker, it will take care of standby, We may not need to shutdown standby nodes.

If you perform swotchover through sqlplus, then you have have to keep only one node in primary and standby and perform switchover.

Thanks,

Sundar

Failover is not done quite often. Its a last resort when you are not able to access the Primary DB.But switchover you perform quite often to test the validity of the Dataguard configuration. In your case DGBROKER is configured. First of all check whether Broker configuration is working properly or not. Then i would suggest you to perform in your environment for switch over using DGBROKER. As if you try to perform manual switchover operation you may not be successful in doing so as broker configuration is on. From my experience we have successful performed switchover using 2 Node RAC with Dataguard in 11g R2 on Solaris 5.11  .

Another option you can opt for instead of performing switch over , enable flashback database on the standby side and temporary open the standby in read write mode fro testing purpose and then once done revert the Stanby database to the earlier state.Follow the link http://docs.oracle.com/cd/B19306_01/server.102/b14239/scenarios.htm#CIHDJICD

Hi,

As per your reply, we can leave all RAC instances up and running at the time of Switchover.

Have you got any document over this?

Thanks,

Narottam

Have you got any document over this?

Please refer this

11gR2 RAC DB switchover using DG broker (Doc ID 880017.1)

HTH

-- Shivananda Rao

Yes 12c that restriction is no more there.

Thanks Shivananda,

I will follow this document.

As per this DOC ID 880017.1, we don't need to shutdown any RAC instances(both primary and physical standby database).Broker will take care of everything.

If it does not work, then I will use sql method.

Thanks,

Narottam

You shouldn't be mixing up SQL with broker while the dataguard is managed by the broker.

Follow the document and you should succeed.

-- Shivananda Rao

With reference to doc.11gR2 RAC DB switchover using DG broker (Doc ID 880017.1)

I checked db configuration on standby database,

with command

$srvctl config database -d dg112i_stb -a

Database unique name: dg112i_stb

Database name: dg112i

Oracle home: /u01/app/oracle/product/11.2.0/dbhome_2

Oracle user: oracle

Spfile: +DATA/dg112i_stb/spfiledg112i.ora

Domain: au.oracle.com

Start options: MOUNT

Stop options: immediate.

But as per doc. it should be 'READ'

How can we change it to 'READ' from 'MOUNT'

Regards,

Narottam

But as per doc. it should be 'READ'
How can we change it to 'READ' from 'MOUNT'

Document does not say that it has to be READ. It's just the configuration what his standby is having and MOUNT is what you have configured for your standby.

This shouldn't be a show stopper. Look out for the DG Broker configuration status, DB status, instance status as per the doc and proceed with the switchover.

-- Shivananda Rao

As per your reply, we can leave all RAC instances up and running at the time of Switchover.
Have you got any document over this?

How the Broker Performs a Switchover.

Notice step 2...the Broker handles the other instances for you.

HTH,
Brian

Hi,

http://docs.oracle.com/cd/B19306_01/rac.102/b14197/srvctladmin.htm#i1008723

1. As per oracle documentation its "Options to startup command (for example: open, mount, or nomount)"

2. As per physical standby you can configure start option as per your requirement, it shouldn't be a show stopper with read

- Pavan Kumar N

Hi Shivananda,

I have got another doc 11.2 Data Guard Physical Standby Switchover Best Practices using the Broker (Doc ID 1305019.1) which describes the prerequisites for switchover operation.

Regards,

Narottam

Thanks all for your support. I did switchover operation successfully.

Thanks all for your support. I did switchover operation successfully.

Please consider closing the thread.

-- Shivananda Rao