How to change database parameter groups in Tanzu Cloud Service Broker for AWS

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• Cloud Services Products

Issue/Introduction

This KB describes the approach to change database parameter groups in Tanzu Cloud Service Broker for AWS, including databases that use custom parameter groups.

Resolution

Parameter groups can be set individually for each database by using the parameter_group_name property at creation/update time.
For example:

> cf create-service csb-aws-postgresql PLAN-1 new-instance-name -c '{"parameter_group_name": "existing-parameter-group"}' > cf update-service new-instance-name -c '{"parameter_group_name": "another-existing-parameter-group"}'

You can also be specified from plans using the same property within the plan definition. In this case you can definitely create two plans, one for the replica stage and a second one for when the the instance has been migrated, with the definite values you wish to keep.

> cf create-service csb-aws-postgresql PLAN-WITH-REPLICA-CONFIG new-instance-name > cf update-service new-instance-name -p DEFINITE-PLAN

Bear in mind that when providing custom parameter groups, setting properties like require_ssl will not take effect and you will have to configure the provided parameter group according their requirements.

Alternatively, the CSB creates a parameter group for each instance if non is provided. Hence if you are not using custom parameter groups, you can update the one the CSB creates for each specific instance with the required configuration via the AWS Console, and then undo the change once the data migration has finished. The naming convention for CSB created parameter groups is rds-pg-<INSTANCE_NAME>.
 

Note, if you don’t specify a parameter group in the plan, then you can always set it on provision/update. If you do specify a parameter group in the plan, then that property cannot be overriden at provision nor update.