Prepare participating clusters

Prepare your participating RECs to be part of an Active-Active database deployment.

Prepare participating clusters

Before you prepare your clusters to participate in an Active-Active database, make sure you've completed all the following steps and have gathered the information listed below each step.

1. Configure the admission controller and ValidatingWebhook.

2. Create two or more RedisEnterpriseCluster (REC) custom resources with enough memory resources.

   • Name of each REC (<rec-name>)
   • Namespace for each REC (<rec-namespace>)

3. Configure the REC ingressOrRoutes field and create DNS records.

   • REC API hostname (api-<rec-name>-<rec-namespace>.<subdomain>)
   • Database hostname suffix (-db-<rec-name>-<rec-namespace>.<subdomain>)

Next you'll collect credentials for your participating clusters and create secrets for the RedisEnterprsieRemoteCluster (RERC) to use.

For a list of example values used throughout this article, see the Example values section.

Preview versions

If you are using a preview version of these features (operator version 6.4.2-4 or 6.4.2-5), you'll need to enable the Active-Active controller with the following steps. You need to do this only once per cluster. We recommend using the fully supported 6.4.2-6 version.

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\"}}"
   

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-name>.

   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-rerc-ohare
   type: Opaque
   
   ---
   
   apiVersion: v1
   data:
     password: 
     username: 
   kind: Secret
   metadata:
     name: redis-enterprise-rerc-reagan
   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 rec-chicago would be similar to this:

   apiVersion: v1
   data:
     password: ABcdef12345
     username: GHij56789
   kind: Secret
   metadata:
     name: rec-chicago
   type: Opaque
   

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

   This example shows the collected secrets file (all-rec-secrets.yaml) for rerc-ohare (representing rec-chicago in namespace ns-illinois) and rerc-reagan (representing rec-arlington in namespace ns-virginia).

   apiVersion: v1
   data:
     password: ABcdef12345
     username: GHij56789
   kind: Secret
   metadata:
     name: redis-enterprise-rerc-ohare
   type: Opaque
   
   ---
   
   apiVersion: v1
   data:
     password: KLmndo123456
     username: PQrst789010
   kind: Secret
   metadata:
     name: redis-enterprise-rerc-reagan
   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.

Example values

This article uses the following example values:

Example cluster 1

• REC name: rec-chicago
• REC namespace: ns-illinois
• RERC name: rerc-ohare
• RERC secret name: redis-enterprise-rerc-ohare
• API FQDN: api-rec-chicago-ns-illinois.example.com
• DB FQDN suffix: -db-rec-chicago-ns-illinois.example.com

Example cluster 2

• REC name: rec-arlington
• REC namespace: ns-virginia
• RERC name: rerc-raegan
• RERC secret name: redis-enterprise-rerc-reagan
• API FQDN: api-rec-arlington-ns-virginia.example.com
• DB FQDN suffix: -db-rec-arlington-ns-virginia.example.com