Upgrading Db2 on Red Hat OpenShift HADR deployments

You can upgrade the Db2 server by editing the source YAML of the custom resource (CR) that is associated with your Db2 on Red Hat OpenShift cluster. When HADR is enabled, the upgrade steps vary depending on the Db2® on OpenShift release to which you are upgrading.

Before you begin

Note: As of s11.5.8.0-cn2, HADR is supported on Db2uInstance CR.

Upgrade your Db2 Operator to the intended version.
The primary and principal standby databases must be in PEER state before you start the upgrade.
If you have created an external etcd store with etcd that is packaged with Db2 , see Upgrading the external etcd store created with the Db2 etcd image for instructions on how to upgrade to the latest image. These steps should be performed after the HADR rolling upgrade is complete, or between steps 17 and 18 in the task procedure.

If you are upgrading to 11.5.7.0 or earlier versions, review the following conditions:

When upgrading to Db2 11.5.7.0 and earlier versions, you need to first stop your HADR deployment, upgrade your Db2uCluster, and then reconfigure your HADR deployment.
Since the release of Db2 11.5.7.0-cn5, the Db2uCluster CR requires NetworkPolicies that permit HADR communication between deployments. If you are upgrading from Db2 11.5.7.0-cn4 or earlier, you need to manually create these NetworkPolicies before upgrading your Db2uCluster instances. See Creating NetworkPolicies for your Db2 on OpenShift HADR deployment upgrade.

About this task

If you are upgrading to the Db2 on OpenShift® 11.5.8 release (including CNs), there is a slight interruption when processing is switched from one database to the other. The duration of the interruption is the time it takes for ACR to switch between the primary and standby connection. The length of this duration depends on how you have configured automatic client reroute (ACR).

Note: This upgrade procedure keeps at least one HADR database available throughout the upgrade process. In previous upgrades to HADR deployments of Db2 on OpenShift 11.5.7, the databases were unavailable during the upgrade process.

Procedure

Modify environment and version variables for your deployments:
```
DB2UCLUSTER_PRIMARY="db2oltp-crd-hadr-primary"
DB2UCLUSTER_STANDBY="db2oltp-crd-hadr-standby"
PROJECT_PRIMARY="zen"
PROJECT_STANDBY="zen"
DB2_VERSION="s11.5.8.0"
```
Db2uCluster names can be obtained with the oc get db2ucluster command, in the namespace where the deployments are located. The DB2_VERSION is the version number to which you want to upgrade. For more information, see Upgrading and updating your Db2 on Red Hat OpenShift cluster.
Run the stop governor command on your deployments.
Note: Governor does not run on auxiliary standbys. This step isn't necessary on auxiliary deployments.
Run the command on your principal standby deployment first, then your primary deployment:
```
oc exec -it c-${DB2UCLUSTER_STANDBY}-db2u-0 -n ${PROJECT_STANDBY} -- sv stop governor
```
```
oc exec -it c-${DB2UCLUSTER_PRIMARY}-db2u-0 -n ${PROJECT_PRIMARY} -- sv stop governor
```
Upgrade your standby deployment.

Patch the Db2uCluster custom resource to the new version:

oc patch db2ucluster ${DB2UCLUSTER_STANDBY} -n ${PROJECT_STANDBY} --type merge -p "{\"spec\":{\"version\":\"${DB2_VERSION}\"}}"

The Db2uCluster returns READY when the standby deployment upgrade is complete.

Return the status:

oc get db2ucluster ${DB2UCLUSTER_STANDBY} -n ${PROJECT_STANDBY}

If there are auxiliary deployments in the HADR topology, upgrade them one at a time. Repeat this step and wait for each deployment to return a READY status.

Do a role switch to the standby database to set it as the new primary database:

oc exec -it c-${DB2UCLUSTER_STANDBY}-db2u-0 -n ${PROJECT_STANDBY} -- su - db2inst1

db2 takeover hadr on db ${DBNAME}

Upgrade the new standby (former primary) deployment.
Patch the Db2uCluster custom resource to the new version:
```
oc patch db2ucluster ${DB2UCLUSTER_PRIMARY} -n ${PROJECT_PRIMARY} --type merge -p "{\"spec\":{\"version\":\"${DB2_VERSION}\"}}"
```
The Db2uCluster returns READY when the standby deployment upgrade is complete.

Return the status:

oc get db2ucluster ${DB2UCLUSTER_PRIMARY} -n ${PROJECT_PRIMARY}

Update the databases.
Run the db2u_update.sh update script on the current primary (former standby) deployment with the -db parameter:
```
oc exec -it c-${DB2UCLUSTER_STANDBY}-db2u-0 -n ${PROJECT_STANDBY} -- bash
```
1. For a deployment on a DB2_VERSION that is earlier than s11.5.9.0, run this command:
```
su - db2inst1 -s /bin/bash -c '/db2u/scripts/db2u_update.sh -db'
```
2. For a deployment on a DB2_VERSION that is s11.5.9.0 or later, run this command:
```
su - db2inst1 -s /bin/bash -lc 'db2_update_upgrade --database'
```
Wait for the log replay to complete.
Ensure that the HADR pair has reached PEER state again by running the following command and reviewing the status:
```
oc exec -it c-${DB2UCLUSTER_STANDBY}-db2u-0 -n ${PROJECT_STANDBY} -- manage_hadr -status
```
Deactivate, then activate the database in the current standby (former primary) deployment:
```
oc exec -it c-${DB2UCLUSTER_PRIMARY}-db2u-0 -n ${PROJECT_PRIMARY} -- su - db2inst1
```
```
db2 deactivate db ${DBNAME}
```
```
db2 activate db ${DBNAME}
```
If there are auxiliary deployments in the HADR topology, repeat this step to deactivate and activate each deployment.

Perform a role switch to revert back to the original primary deployment by running the following command:

oc exec -it c-${DB2UCLUSTER_PRIMARY}-db2u-0 -n ${PROJECT_PRIMARY} -- su - db2inst1

db2 takeover hadr on db ${DBNAME}

Deactivate, then activate the database in the standby deployment by running the following command:

oc exec -it c-${DB2UCLUSTER_STANDBY}-db2u-0 -n ${PROJECT_STANDBY} -- su - db2inst1

db2 deactivate db ${DBNAME}

db2 activate db ${DBNAME}

Start the governor on the primary deployment:

oc exec -it c-${DB2UCLUSTER_PRIMARY}-db2u-0 -n ${PROJECT_PRIMARY} -- su - db2inst1

${HOME}/governor/governor.sh start

Start the governor on the standby deployment:
```
oc exec -it c-${DB2UCLUSTER_STANDBY}-db2u-0 -n ${PROJECT_STANDBY} -- su - db2inst1
```
```
${HOME}/governor/governor.sh start
```
Your HADR Db2 on OpenShift deployment is now upgraded to the 11.5.9.0 release.