Running twemproxy on Kubernetes

Deployments and Services for the redis nodes and twemproxy are found in their respective .yaml files in deployments/ and services/.

The port for twemproxy is 22121, and redis is 6379

quickReset.sh deletes all deployments and services for quicker development, and quickStart.sh starts up the redis nodes and twemproxies.

Upon starting up a twemproxy pod, twemproxy/run-twemproxy.sh is started. This starts the config monitor in the background and is responsible for starting the nutcracker/twemproxy process once a twemproxy.yaml file is created.

twemproxy/config-monitor.sh monitors any changes in the twemproxy config file that is generated by create-config.py. If the config file is different than the previous one, the twemproxy process is killed and restarted with the new config file.

create-config.py uses the kubernetes API to get all redis pods (identified by the label name: redis-node), and creates a temproxy config file with the IPs of each of those pods.

# Start the redis-node pods
kubectl create -f deployments/redis-node.yaml
kubectl create -f services/redis-node.yaml

# And start the twemproxy pods
kubectl create -f deployments/twemproxy.yaml
kubectl create -f services/twemproxy.yaml

Alternatively, just run quickStart.sh

To access twemproxy through the redis-cli:

kubectl port-forward [twemproxy-pod-name] 6379:22121

In a separate terminal:

redis-cli

# Check that it works:

127.0.0.1:6379> ping
PONG
127.0.0.1:6379> set foo bar
OK
127.0.0.1:6379> get foo
bar

To access a redis instance directly to test sharding:

kubectl port-forward [redis-node-pod-name] 6379:6379

If a redis-node pod is deleted, a new pod is created and twemproxy is restarted (if necessary) to use this new pod's IP.