PubSub with Redis adapter need a help

I’ve been working with Phoenix app 1.2.5 and we are using PubSub which came by default and we started to check the alternative using PubSub Redis Adapter from ( Everything looks good in the configuration also Redis services are running properly too. But the web socket stopped to deliver the messages. Do we need to set more than the adapter configuration to make it work properly? Sorry I have thought it was just to replace the configuration for the adapter.

The new config is.

  pubsub: [name: MyApp.PubSub,
       adapter: Phoenix.PubSub.Redis,
       host: System.get_env("REDIS_HOST") || "",
       node_name: System.get_env("NODE") || "NODE_1"]