Externalize Redis¶

Follow the official Redis 6 upgrade — On-cluster chapter. You need two instances (backend and system). Redis Cluster is not supported. Full runbook: docs/runbooks/02-externalize-redis.md (Git Bash: docs/runbooks/02-bis-externalize-redis-windows.md).

Use the same export variables as Externalize PostgreSQL. Set REDIS_NAMESPACE=3scale-db.

1. Scale down 3scale (keep embedded Redis up)¶

This step assumes PostgreSQL externalization already scaled embedded Redis back up. Scale the 3scale operator and 3scale components to 0 except backend-redis and system-redis:

oc scale deployment threescale-operator-controller-manager-v2 -n "$OPERATOR_NAMESPACE" --replicas=0
oc scale deployment/{system-memcache,zync-database,apicast-production,apicast-staging,backend-cron,backend-listener,backend-worker,system-app,system-sidekiq,system-searchd,zync,zync-que} --replicas=0

Wait for Redis to flush data to disk before the dump.

2. Copy `dump.rdb`¶

oc cp "$(oc get pods -l deployment=backend-redis -o jsonpath='{.items[0].metadata.name}')":/var/lib/redis/data/dump.rdb ./backend-redis-dump.rdb
oc cp "$(oc get pods -l deployment=system-redis -o jsonpath='{.items[0].metadata.name}')":/var/lib/redis/data/dump.rdb ./system-redis-dump.rdb
oc scale deployment/system-redis --replicas=0
oc scale deployment/backend-redis --replicas=0

3. Deploy Redis 7¶

oc apply -k kustomize/overlays/lab

The restore ConfigMap sets save "" and appendonly no (required to load the RDB). Wait for backend-redis-external and system-redis-external at 1/1.

4. Restore RDB and rewrite AOF¶

export REDIS_NAMESPACE=3scale-db
oc cp ./backend-redis-dump.rdb "$(oc get pods -n "$REDIS_NAMESPACE" -l deployment=backend-redis-external -o jsonpath='{.items[0].metadata.name}')":/var/lib/redis/data/dump.rdb -n "$REDIS_NAMESPACE"
oc cp ./system-redis-dump.rdb "$(oc get pods -n "$REDIS_NAMESPACE" -l deployment=system-redis-external -o jsonpath='{.items[0].metadata.name}')":/var/lib/redis/data/dump.rdb -n "$REDIS_NAMESPACE"
oc rollout restart deployment/backend-redis-external -n "$REDIS_NAMESPACE"
oc rollout restart deployment/system-redis-external -n "$REDIS_NAMESPACE"

When the pods are Ready, run redis-cli BGREWRITEAOF in each pod and wait for aof_rewrite_in_progress = 0. Re-read pod names after the restart.

5. Enable persistence¶

oc apply -k kustomize/overlays/lab-persist

Or switch GitOps redis-config.path to kustomize/bases/redis-config-persist. Restart the Redis Deployments. Confirm the ConfigMap no longer has save "" and appendonly is yes.

6. Patch secrets and the APIManager¶

Patch system-redis and backend-redis secrets with the external service URLs. Then set externalComponents for both Redis instances on the APIManager. Scale all components back up.

Capture replicas before scale-down

If you captured replica variables after scale-down, they may be 0. Use explicit --replicas=1 (or the original count) when you scale up.