A customer of mine hit an issue recently when upgrading to Oracle Database 12.2.0.1. They did everything correctly but received a ton of issues from the Data Guard Broker. A rule says: When you upgrade, disable the Data Guard Broker. But I can’t blame the customer as this “rule” is well hidden in the documentation.
When you upgrade, disable the Data Guard Broker
First of all, the Data Guard Broker is required if you would like to administer your databases in Oracle Cloud Control. Otherwise you can’t switchover or failover within Enterprise Manager. But once you approach a database upgrade please disable the Data Guard Broker while you do the upgrade. Enable the Broker after the upgrade again.
In an Oracle Data Guard configuration the Broker is always the boss. If you do something the Broker does not like – and you did it via SQL Plus and not via the Broker’s command line DGMGRL tool – the Broker will change your change. Bet with me.
From Oracle 12.1 High Availability Guide – can be found at: https://docs.oracle.com/database/121/DGBKR/configure.htm#DGBKR3659
Therefore you must disable the Data Guard Broker when you upgrade your primary database. Otherwise the Broker will interfere with the upgrade and cause trouble.
Where is this documented?
The crucial point is that you most likely won’t be able to find this piece of information in the documentation unless you studied the Data Guard’s Broker manual carefully. When you read through the steps to upgrade a database in a physical standby environment you were not able to find a hint.
Thanks to my colleagues from the MAA / Data Guard Team we updated the documentation.
- If you are using the Oracle Data Guard broker to manage your configuration, follow the instructions in the Oracle Data Guard Broker manual for information about removing or disabling the broker configuration.
It will guide you to this section explaining clearly how to disable (and enable afterwards) the Data Guard Broker while you upgrade your primary database.
How to upgrade your database with a physical standby in place?
I won’t replicate the documentation as the Data Guard documentation is usually very good and precise. But it is important that you don’t skip this part:
Then you proceed with:
In brief a very short summary:
- Disable the Data Guard Broker configuration
- Install the new software on the standby host and patch it with the newest RU
- Install the new software on the primary host as well and patch it with the newest RU
- Download the most recent
preupgrade.jar(for instance the September 2017 one) and execute it on your primary - Shutdown everything on the standby and restart listeners etc with the new environment
- Mount the physical standby and start redo apply
- Upgrade the primary database as explained in the Database Upgrade Guide
- After the upgrade has been completed the standby has been upgraded via log apply as well
- Enable the Data Guard Broker configuration
An additional comment
I received this comment via LinkedIn and it’s worth to mention:
Having performed many such upgrades, I have found the safest method is to defer log shipping from the Primary to stop alerts and keep the Standby shut down until after the Primary is successfully upgraded. Only after upgrade mount the Standby and enable configuration (enable shipping and start redo apply). That way a failed Primary upgrade would not be replicated to the Standby.
–Mike
Mike,
You’re talking about the 12.2 upgrade here. Do you have any information about broker problems with application of 11.2.0.4.171017?
John,
do you mean general broker issues? No, unfortunately not.
Thanks, Mike
Hello,
Thank you for all your useful information regarding the Oracle Database, I often refer to your website for assistance in my daily DBA duties.
I am writing you to let you know I have been testing 12c Data Gaurd upgrade to 18c. We currently have Streams in our architecture so we are not ready to move to 19c where Streams is desupported. I followed your instructions and the referenced documentation to disable Data Gaurd prior to the upgrade. However, the three times I have tried to re-enable Data Gaurd, following the steps on your site, I get a message from DGMGRL that there is no configuration found. I made sure that dgmgrl was using the 18c binaries. I verified that all the .dat files were available and I tested using the backed up .dat files and none of them worked. All three times I had to rebuild Data Gaurd configuration. Unfortunately, after filing an SR with Oracle requesting the upgrade documentation from 12c to 18c for the Data Gaurd, it does not exists. The referenced documentation is for upgrade to 12c. Can you help me?
Hi Ken,
do you have an SR opened for this?
I can’t diagnose such things just with an explanation. But I can look into an SR to see and understand what was going wrong.
Thanks,
Mike
Mike,
I had one open previously and was referred to an older document for upgrade to 12c. I work in a highly classified environment so, I am unable to provide trace files or too much information other than high level information. I was hoping to either get a reference for a newer document for 18c data upgrade or a referral to a website.
3-22879011521
Hi Ken,
I looked at the SR, and I agree that this looks like a Broker issue.
But I see also that you’ve rebuilt the environment now?
Thanks,
Mike
Yes, I have gotten everything to work. One thing I did differently was start the observer before I tried to re-enable Data Gaurd Manager. Also, I replaced the *.dat files from backup to replace the old ones obtained prior to the upgrade. I’m not sure which action or if both allowed me have Data Gaurd Manager to enable configuration.
Thank you for all your useful information, I just though this piece of information will be useful to the readers, this step needs to be done on Standby otherwise will not be able to use srvctl commands
/bin/srvctl upgrade database -d -o
Thanks John!
Cheers,
Mike