Add a participating cluster

Use the following steps to add a participating cluster to an existing Redis Enterprise Active-Active database (REAADB) for Kubernetes.

Prerequisites

To prepare the Redis Enterprise cluster (REC) to participate in an Active-Active database, perform the following tasks from Prepare participating clusters:

  • Make sure the cluster meets the hardware and naming requirements.
  • Enable the Active-Active controllers.
  • Configure external routing.
  • Configure ValidatingWebhookConfiguration.

Collect REC credentials

To communicate with other clusters, all participating clusters need access to the admin credentials for all other clusters.

  1. Get the REC credentials secret for the new participating cluster.

    kubectl get secret -o yaml <rec-name>

    This example shoes an admin credentials secret for an REC named rec3:

    apiVersion: v1
data:
  password: ABcdef12345
  username: GHij56789
kind: Secret
metadata:
  name: rec3
type: Opaque

  2. Create a secret for the new participating cluster named redis-enterprise-<rerc> and add the username and password.

    The example below shows a secret file for a remote cluster named rerc3 .

    apiVersion: v1
data:
  password: ABcdef12345
  username: GHij56789
kind: Secret
metadata:
  name: redis-enterprise-rerc3
type: Opaque

  3. Apply the file of collected secrets to every participating REC.

    kubectl apply -f <rec-secret-file>

If the admin credentials for any of the clusters change, update and reapply the file to all clusters.

Create RERC

  1. From one of the existing participating clusters, create a RedisEnterpriseRemoteCluster (RERC) custom resource for the new participating cluster.

This example shows a RERC custom resource for an REC named rec3 in the namespace ns3.

apiVersion: app.redislabs.com/v1alpha1
kind: RedisEnterpriseRemoteCluster
metadata:
  name: rerc3
spec:
  recName: rec3
  recNamespace: ns3
  apiFqdnUrl: test-example-api-rec3-ns3.redis.com
  dbFqdnSuffix: -example-cluster-rec3-ns3.redis.com
  secretName: redis-enterprise-rerc3
  1. Create the RERC custom resource.
kubectl create -f <new-RERC-file>
  1. Check the status of the newly created RERC custom resource.
kubectl get rerc <RERC-name>

The output should look like this:

NAME        STATUS   SPEC STATUS   LOCAL
rerc3   Active   Valid         true

Edit REAADB spec

  1. Patch the REAADB spec to add the new RERC name to the participatingClusters, replacing <reaadb-name> and <rerc-name> with your own values.
kubectl patch reaadb <reaadb-name> < --type merge --patch '{"spec": {"participatingClusters": [{"name": "<rerc-name>"}]}}'
  1. View the REAADB participatingClusters status to verify the cluster was added.
kubectl get reaadb <reaadb-name> -o=jsonpath='{.status.participatingClusters}'

Output should look like this:

[{"id":1,"name":"rerc1"},{"id":2,"name":"rerc2"},{"id":3,"name":"rerc3"}]

Remove a participating cluster

On an existing participating cluster

Remove the desired cluster from the participatingCluster section of the REAADB spec.

kubectl edit reaadb <reaadb-name>

On each of the other participating clusters

Verify the status is active and the spec status is Valid and the cluster was removed.

kubectl get reaadb <reaadb-name -o=jasonpath=`{.status}`

On the removed participating cluster

List all REAADB resources on the cluster to verify they were deleted.

kubectl get reaadb -o+jasonpath=`{range.items[*]}{.metadata.name}`