RDS Multi-AZ MySQL Cluster Parameter Group Won't Change

Question

I am using the new RDS Multi-AZ MySQL cluster service and I am unable to change out the parameter group to a custom one I've made.

1. I create a new Parameter group
2. Then go into my RDS databases, select the cluster I want to modify, click "Modify" button,
3. Edit the Parameter Group section with the new Parameter Group.
4. Press Continue and then select the "Apply immediately" option, click "Modify cluster" button.

When viewing the cluster's "Configuration" tab, it will show the name of the updated Parameter Group, but when viewing each writer/reader node's "Configuration" tab, the Parameter Group will still stay the same:

![Enter image description here](/media/postImages/original/IMSFKYMOhIR5S6uVbKlXVyEA)

I have been unable to change their Parameter group ever, not once! Even a restart of each node does not update the parameter group. I can't figure out what I am doing wrong here. Has anyone had the same experience?

Accepted Answer

I was able to get the parameter group changed and verified using the AWS RDS CLI tool. Once the change was made via the CLI, the UI still DID NOT reflect the changes.

**I am going to sum this up to a UI/Javascript bug in the AWS console.**

How to do it via CLI:

```
aws rds modify-db-cluster --db-cluster-identifier {your-cluster-id} --db-cluster-parameter-group-name {your-cluster-parameter-group-id} --apply-immediately
```

Then restart cluster (also something I cannot do in the UI)

```
aws rds reboot-db-cluster --db-cluster-identifier {your-cluster-id}
```

**Guides:**

**CLI tool install:**
https://docs.aws.amazon.com/cli/latest/userguide/getting-started-install.html#getting-started-install-instructions

**CLI tool configuration:**
https://docs.aws.amazon.com/cli/latest/userguide/getting-started-quickstart.html

Answer

There is a parameter group option for the DB instances (writer/reader nodes), which is different from the DB cluster parameter group. If you select one of your DB instances, and choose Modify, you can see the two parameter group options. Here is an example for an Aurora DB instance:
![DB Options - Parameter Group](/media/postImages/original/IMgR9xmsvKTX-8LsPZl5zDQA)

If you want to change the parameter group for the DB instances (writer/reader nodes), then you must update the second field `DB parameter group`.

If you've created an RDS DB cluster/instances and initially just used the default parameter groups, you can see the two different types of parameter groups automatically created (`DB cluster parameter group` and `Parameter groups` which is for DB instances).

See below example for aurora-mysql8.0 default parameter groups:
![Enter image description here](/media/postImages/original/IMLocrcL3xT862gyhi-DCAjw)

More information about RDS parameter groups can be found here: https://docs.aws.amazon.com/AmazonRDS/latest/UserGuide/USER_WorkingWithParamGroups.html

RDS Multi-AZ MySQL Cluster Parameter Group Won't Change

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