Changing Db2 or Db2 Warehouse Configuration Settings

Db2 or Db2 Warehouse configuration settings can be permanently changed after deployment by editing the Db2uInstance custom resource.

Database configuration parameters (db cfg)
Database manager configuration parameters (dbm cfg)
Registry and environment variables (db2set)

Note: Exercise caution when modifying advanced settings as they can have significant impacts on system behavior and stability. It can take a few minutes for Kubernetes to update the ConfigMap data inside a pod. Once values are updated, Db2 will update it settings as well and restart or reactivate the database if needed.

Procedure

Determine the DB2U_IDENTIFIER to use that matches your Db2 deployment. The identifier matches the name of the custom resource (CR) that is used to deploy Db2. Run the following command to retrieve the name of the CR:
```
kubectl get db2uinstance -n NAMESPACE
```
Edit the custom resource. This will open the custom resource definition in your default editor:
```
kubectl edit db2uinstance DB2UINSTANCE -n NAMESPACE
```

Database configuration parameters

Database configuration parameters are found under the yaml path spec.environment.databases.dbConfig. Each database has a list under the key databases with its own unique name.

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 look like so:

spec:
  environment:
    databases:
    - dbConfig:
        LOGPRIMARY: "50"
      name: BLUDB

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

Database manager configuration parameters

Database manager configuration parameters are found under 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 look like so:

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

For more information on the parameters, 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 look like so:

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

For more information on the parameters, see Registry and environment variables in Db2 or Db2 Warehouse documentation.