Prepare participating clusters

An Active-Active database can span multiple clusters. Make sure you have enough memory resources available for the database (see hardware requirements).

Cluster names

The combination of the REC name and namespace (<rec-name>.<namespace-name>) must be unique for each participating cluster the Active-Active database.

For example, if you have two K8s clusters, each with their own REC named rec1 in a namespace named ns1. The value of <rec-name>.<namespace-name> for both RECs would be rec1.ns1. These can’t be used for the same Active-Active database.

Enable Active-Active controllers

To allow operator to handle managed Active-Active databases, enable the Active-Active and remote cluster controllers. You need to do this only once per cluster.

  1. Download the custom resource definitions (CRDs) for the most recent release (6.4.2-4) from redis-enterprise-k8s-docs Github.

  2. Apply the new CRDs for the Redis Enterprise Active-Active database (REAADB) and Redis Enterprise remote cluster (RERC) to install those controllers.

    kubectl apply -f crds/reaadb_crd.yaml
kubectl apply -f crds/rerc_crd.yaml

  3. Enable the Active-Active and remote cluster controllers on the operator ConfigMap.

    kubectl patch cm  operator-environment-config --type merge --patch "{\"data\": \
{\"ACTIVE_ACTIVE_DATABASE_CONTROLLER_ENABLED\":\"true\", \
\"REMOTE_CLUSTER_CONTROLLER_ENABLED\":\"true\"}}"

Configure external routing

Active-Active databases require external routing access to sync properly. To configure external routing through an ingress or OpenShift route, see Establish external routing on the REC.

Configure ValidatingWebhookConfiguration

The admission controller using a validating webhook to dynamically validate resources configured by the operator. The ValidatingWebhookConfiguration is required for Active-Active databases. Learn how to enable and configure admission controller in the Enable admission controller section of the Deploy Redis Enterprise Software for Kubernetes instructions.

Collect REC credentials

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

  1. Create a file to hold the admin credentials for all participating RECs (such as all-rec-secrets.yaml).

  2. Within that file, create a new secret for each participating cluster named redis-enterprise-<rerc>.

    The example below shows a file (all-rec-secrets.yaml) holding secrets for two participating clusters:

    apiVersion: v1
data:
  password: 
  username: 
kind: Secret
metadata:
  name: redis-enterprise-rerc1
type: Opaque

---

apiVersion: v1
data:
  password: 
  username: 
kind: Secret
metadata:
  name: redis-enterprise-rerc2
type: Opaque

  3. Get the REC credentials secret for each participating cluster.

    kubectl get secret -o yaml <rec-name>

    The admin credentials secret for an REC named rec1 would be similar to this:

    apiVersion: v1
data:
  password: ABcdef12345
  username: GHij56789
kind: Secret
metadata:
  name: rec1
type: Opaque

  4. Add the username and password new secret for that REC and namespace.

    This example shows the collected secrets file (all-rec-secrets.yaml) for rec1 in namespace ns1 and rec2 in namespace ns2.

    apiVersion: v1
data:
  password: ABcdef12345
  username: GHij56789
kind: Secret
metadata:
  name: redis-enterprise-rerc1
type: Opaque

---

apiVersion: v1
data:
  password: KLmndo123456
  username: PQrst789010
kind: Secret
metadata:
  name: redis-enterprise-rerc2
type: Opaque

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

    kubectl apply -f <all-rec-secrets-file>

If the admin credentials for any of the clusters changes, the file will need to be updated and reapplied to all clusters.

Next steps

Now you are ready to create your Redis Enterprise Active-Active database.