Changing Db2 configuration settings

You can change configuration settings after you deploy your instance by editing the Db2uCluster or Db2uInstance custom resource.

1. Find the Db2uCluster or Db2uInstance custom resource that you want to configure and assign it to an environment variable.
   1. Retrieve a list of your Db2uCluster and Db2uInstance custom resources from Data > Databases > Database Details in the IBM® Software Hub web client, or by running the following command:

      oc get db2ucluster,db2uinstance -n ${PROJECT_CPD_INST_OPERANDS}

   2. Set the Db2uCluster or Db2uInstance custom resource name to the DB2_CR_ID environment variable:

      DB2_CR_ID=<db2ucluster_cr_name/db2uinstance_cr_name>

      For example, DB2_CR_ID=db2oltp-1748840598043123
2. Run the following command to edit the Db2uCluster or Db2uInstance custom resource:

   oc edit db2ucluster ${DB2_CR_ID} -n ${PROJECT_CPD_INST_OPERANDS}

   oc edit db2uinstance ${DB2_CR_ID} -n ${PROJECT_CPD_INST_OPERANDS}

3. Change the following configuration settings.

   Database configuration parameters

   To find your database configuration parameters, see the yaml path spec.environment.database.dbConfig.

   Under the key dbConfig, you can add, edit, or delete a key-value pair. Values must be enclosed in quotation marks.

   For example, setting the parameter LOGPRIMARY to 50 for the database BLUDB would appear as follows:

   spec:
     environment:
       database:
        dbConfig:
           LOGPRIMARY: "50"
         name: BLUDB

   For more information, see Database configuration parameters in the Db2 documentation.

   Database manager configuration parameters

   To find your database manager configuration parameters, see the yaml path: spec.environment.instance.dbmConfig.

   Under the key dbmConfig, you can add, edit, or delete a key-value pair. Values must be enclosed in quotation marks. For example, setting the parameter DIAGSIZE to 50 would appear as follows:

   spec:
     environment:
       instance:
         dbmConfig:
           DIAGSIZE: "100"
   

   For more information, see Database manager configuration parameters in Db2 documentation.

   Registry and environment variables

   Registry configuration parameters are found under the yaml path: spec.environment.instance.registry.

   Under the key registry, you can add, edit, or delete a key-value pair. Values must be enclosed in quotation marks. For example, setting the parameter DB2_DISPATCHER_PEEKTIMEOUT to 5 would appear as follows:

   spec:
     environment:
       instance:
         registry:
           DB2_DISPATCHER_PEEKTIMEOUT: "5"

   For more information, see Registry and environment variables in the Db2 documentation.

4. To change the name of the default Db2 database, complete the following steps.
   1. Run the following command, substituting the new default database name for MYDB:

      oc patch db2ucluster -n ${PROJECT_CPD_INST_OPERANDS} ${DB2_CR} --type merge -p '{"spec":{"environment":{"database":{"name":"MYDB"}}}}'

      oc patch db2uinstance -n ${PROJECT_CPD_INST_OPERANDS} ${DB2_CR} --type merge -p '{"spec":{"environment":{"database":{"name":"MYDB"}}}}'

   2. Verify that the corresponding db2uconfig configMap reflects the changed DBNAME value:

      oc get cm -n ${PROJECT_CPD_INST_OPERANDS} -o yaml c-${DB2_CR}-db2uconfig | grep DBNAME

   3. Find the engine pod of the database that you want to change by running the following command:

      DB2_ENG_POD=$(oc get po -l app=${DB2_CR},type=engine)

   4. Delete one or more corresponding Db2 engine pods to enable the configMap changes to take effect.

      oc delete pods -n ${PROJECT_CPD_INST_OPERANDS} ${DB2_ENG_POD}

5. Exec into the Db2 engine pod as the db2inst1 user and use the following command to apply the updates:

   oc exec -it c-${DB2_CR_ID}-db2u-0 -- su - db2inst1 -c "/db2u/scripts/apply-db2cfg-settings.sh --setting all"