Ellison, Master of sentinels for client that cannot use them.
Redis provides sentinels to elect a leader (master) that is able to write data when a master falls. That is very impressive and allows Redis High Availability. But sometimes, clients (frameworks, libraries...) are not able to use sentinels. Actually, the client must know if sentinels exists and should make a request to get master address to write data.
Redis-Ellison is a proxy that will interact with sentinels and master to send and get data from the master (as this time, it cannot make distinction between get and set), so that clients can connect Redis Ellison as if it was the master, and ellison will make data routing.
Ellison is scallable, so you can use it in a PaaS as Openshift/Kubernetes and scale up. The "service" will load-balance on each Redis-Ellison server.
NOTE: At this time, you need "redis-cli" command installed on your server to be able to contact sentinels. That should change in later revisions.
You may get docker image:
docker pull metal3d/redis-ellison
docker run --rm -it metal3d/redis-ellison
At this time, you should use "go get" command.
go get -u github.com/metal3d/redis-ellison
Usage of ellison:
-cluster string
redis cluster name (default "mymaster")
-redis-command string
redis command to connect to sentinel, it can also be "docker exec sentinel1 redis-cli" for example (default "redis-cli")
-sentinel-host string
sentinel host or ip (default "127.0.0.1")
-sentinel-port string
sentinel port to connect (default "26379")
Note: each flag can be overriden by an environment variable that respect the flag.:
CLUSTER- default to "mymaster"REDIS_COMMAND- default to "redis-cli"SENTINEL_HOST- default to "127.0.0.1"SENTINEL_PORT- default to "26379" (redis port + 2000)
So that, it's simpler to inject configuration in a Docker container.
Sentinel host/port should be set to the service managing sentinels. So that if a sentinel is lost, the route will be set to another sentinel.