Prepare Clusters

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]({{< relref "/operate/kubernetes/7.8.4/deployment/quick-start.md#enable-the-admission-controller/" >}}).

2. Create two or more [RedisEnterpriseCluster (REC) custom resources]({{< relref "/operate/kubernetes/7.8.4/deployment/quick-start#create-a-redis-enterprise-cluster-rec" >}}) with enough [memory resources]({{< relref "/operate/rs/installing-upgrading/install/plan-deployment/hardware-requirements.md" >}}).

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

3. Configure the REC [ingressOrRoutes field]({{< relref "/operate/kubernetes/7.8.4/networking/ingressorroutespec.md" >}}) and [create DNS records]({{< relref "/operate/kubernetes/7.8.4/networking/ingressorroutespec#configure-dns/" >}}).

   • 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.

   shCopy

   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.

   shCopy

   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:

   yamlCopy

   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.

   shCopy

   kubectl get secret -o yaml <rec-name>
   

   The admin credentials secret for an REC named rec-chicago would be similar to this:

   yamlCopy

   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).

   yamlCopy

   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.

   shCopy

   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]({{< relref "/operate/kubernetes/7.8.4/active-active/create-reaadb.md" >}}).

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