var io = 3000;var redis = ;io;
By running socket.io with the
socket.io-redis adapter you can run
multiple socket.io instances in different processes or servers that can
all broadcast and emit events to and from each other.
If you need to emit events to socket.io instances from a non-socket.io process, you should use socket.io-emitter.
uri is a string like
localhost:6379 where your redis server
is located. For a list of options see below.
The following options are allowed:
key: the name of the key to pub/sub events on as prefix (
host: host to connect to redis on (
port: port to connect to redis on (
subEvent: optional, the redis client event name to subscribe to (
pubClient: optional, the redis client to publish events on
subClient: optional, the redis client to subscribe to events on
requestsTimeout: optional, after this timeout the adapter will stop waiting from responses to request (
withChannelMultiplexing: optional, whether channel multiplexing is enabled (a new subscription will be trigggered for each room) (
If you decide to supply
subClient, make sure you use
node_redis as a client or one
with an equivalent API.
If you supply clients, make sure you initialized them with
return_buffers option set to
You can supply ioredis as a client
messageBuffer as the subEvent option.
The redis adapter instances expose the following properties
that a regular
Adapter does not
Returns the list of client IDs connected to
rooms across all nodes. See Namespace#clients(fn:Function)
Returns the list of rooms the client with the given ID has joined (even on another node).
subClient properties of the
Redis Adapter instance to subscribe to its
var redis = ;var adapter = ;adapterpubClient;adaptersubClient;
If you need to create a redisAdapter to a redis instance that has a password, use pub/sub options instead of passing a connection string.
var redis = createClient;var adapter = ;var pub = ;var sub = ;io;
Make sure the
return_buffers option is set to
true for the sub client.
socket.io-redis adapter broadcasts and receives messages on particularly named Redis channels. For global broadcasts the channel name is:
prefix + '#' + namespace + '#'
In broadcasting to a single room the channel name is:
prefix + '#' + namespace + '#' + room + '#'
prefix: The base channel name. Default value is
socket.io. Changed by setting
namespace: See https://github.com/socketio/socket.io#namespace.
room: Used if targeting a specific room.
A number of other libraries adopt this protocol including: