This is a (proof of concept) Docker image for https://github.com/facebook/mcrouter which tries to automatically discover memcached servers using DNS on Docker Swarm.
Scaling up or down memcached replicas will cause mcrouter to be re-configured automatically.
Things not done yet: proper configuration (routes etc) beyond the server pools.
https://hub.docker.com/r/kevbuk/mcrouter-swarm
MCROUTER_POOL_[name]=tasks.memcached - Create a pool called [name]. The value is a DNS address which resolves the memcached servers to use for that pool. On Docker Swarm this can be tasks.[service-name].
MCROUTER_PORT_[name]=11211 - The port to use for servers in pool [name]. They must all use the same port.
MCROUTER_ROUTE=PoolRoute|[name] - A route (string). In the future there should be a way to configure complex routes.
MCROUTER_PORT - The port to expose mcrouter server on
docker stack deploy -c docker-compose.yml demo
Watch the logs for reconfigured 1 proxies with 2 pools
Try scaling:
docker service scale demo_memcached=3
You should see the logs say reconfigured 1 proxies with 3 pools
The init script has updated the mcrouter config file and mcrouter has updated without restarting!