Redis Clustering with cluster aware client #

The following guide shows you how to configure Shotover to support proxying Redis cluster aware clients to Redis cluster.

Overview #

In this example, we will be connecting to a Redis cluster that has the following topology:

• 172.16.1.2:6379
• 172.16.1.3:6379
• 172.16.1.4:6379
• 172.16.1.5:6379
• 172.16.1.6:6379
• 172.16.1.7:6379

Shotover will be deployed as a sidecar to each node in the Redis cluster, listening on 6380. Use the following docker-compose.yaml to run the Redis cluster and Shotover sidecars.

curl -L https://raw.githubusercontent.com/shotover/shotover-examples/main/redis-cluster-1-1/docker-compose.yaml --output docker-compose.yaml

Below we can see an example of a Redis node and it's Shotover sidecar. Notice they are running on the same network address (172.16.1.2) and the present directory is being mounted to allow Shotover to access the config and topology files.

redis-node-0:
  image: bitnami/redis-cluster:6.0-debian-10
  networks:
    cluster_subnet:
      ipv4_address: 172.16.1.2
  environment:
    - 'ALLOW_EMPTY_PASSWORD=yes'
    - 'REDIS_NODES=redis-node-0 redis-node-1 redis-node-2'

shotover-0:
  restart: always
  depends_on:
    - redis-node-0
  image: shotover/shotover-proxy
  network_mode: "service:redis-node-0"
  volumes:
    - type: bind
      source: $PWD
      target: /config

In this example we will use redis-benchmark with cluster mode enabled as our Redis cluster aware client application.

Configuration #

First we will modify our topology.yaml file to have a single Redis source. This will:

• Define how Shotover listens for incoming connections from our client application (redis-benchmark).
• Configure Shotover to connect to the Redis node via our defined remote address.
• Configure Shotover to rewrite all Redis ports with our Shotover port when the cluster aware driver is talking to the cluster, through Shotover.
• Connect our Redis Source to our Redis cluster sink (transform).

---
sources:
  redis_prod:
    Redis:
      listen_addr: "0.0.0.0:6380"
chain_config:
  redis_chain:
    - RedisClusterPortsRewrite:
         new_port: 6380
    - RedisSinkSingle:
        remote_address: "0.0.0.0:6379"
        connect_timeout_ms: 3000
source_to_chain_mapping:
  redis_prod: redis_chain

Modify an existing topology.yaml or create a new one and place the above example as the file's contents.

You will also need a config.yaml to run Shotover.

curl -L https://raw.githubusercontent.com/shotover/shotover-examples/main/redis-cluster-1-1/config.yaml --output config.yaml

Starting #

We can now start the services with:

docker-compose up -d

Testing #

With everything now up and running, we can test out our client application. Let's start it up!

First we will run redis-benchmark directly on our cluster.

redis-benchmark -h 172.16.1.2 -p 6379 -t set,get --cluster 

If everything works correctly you should see the following, along with the benchmark results which have been omitted for brevity. Notice all traffic is going through the Redis port on 6379.

Cluster has 3 master nodes:

Master 0: d5eaf45804215f80cfb661928c1a84e1da7406a9 172.16.1.3:6379
Master 1: d774cd063e430d34a71bceaab851d7744134e22f 172.16.1.2:6379
Master 2: 04b301f1b165d81d5fb86e50312e9cc4898cbcce 172.16.1.4:6379

Now run it again but on the Shotover port this time.

redis-benchmark -h 172.16.1.2 -p 6380 -t set,get --cluster 

You should see the following, notice that all traffic is going through Shotover on 6380 instead of the Redis port of 6379:

Cluster has 3 master nodes:

Master 0: 04b301f1b165d81d5fb86e50312e9cc4898cbcce 172.16.1.4:6380
Master 1: d5eaf45804215f80cfb661928c1a84e1da7406a9 172.16.1.3:6380
Master 2: d774cd063e430d34a71bceaab851d7744134e22f 172.16.1.2:6380