redis-party

A redis client wrapper to support cluster connections.

This library can be used as a drop-in replacement for the regular node_redis client.

Install

npm install redis-party

Example

var nodes = [
    {"host": "node1.domain.com", "port": 10000},
    {"host": "node1.domain.com", "port": 10001},
    {"host": "node2.domain.com", "port": 10000},
    {"host": "node2.domain.com", "port": 10001},
];
var redis = require("redis-party");

var cluster = new redis.Cluster(nodes, {"max_attempts": 5});
cluster.once("ready", function () {
    cluster.SET("hello", "planet");

    var multi = cluster.multi();
    multi.SET("hello", "world");
    multi.GET("hello");
    multi.DEL("hello");
    multi.exec(function (err, res) {
        console.log("hello " + res[1]);
    });

    var multi2 = cluster.multi();
    multi2.SET("key1", "val");
    multi2.SET("key2", "val");
    multi2.exec(function (err, res) {
        //err = Error("Multi comands must operate on the same slot!")
    });

    cluster.PUBLISH("key1", "hello world!");
});

Alternative node_redis compatible interface:

var client = redis.createClient(port, host, options);
client.SET("foo", "bar", function () {
    client.GET("foo", function (err, bar) {
        console.log("foo = " + bar);
    });
});

Sending Commands

Just like node_redis, each redis command is exposed as a function on the client object.

All commands except multi are passed along to the correct node_redis client depending on the key hash.

API

Client Events

ready

The client will emit the ready event once the client is connected to the cluster and has populated the slot-node mapping table.

error

This client will emit the error event if there is an error with the cluster library.

redis_error

Error events emitted from the node_redis library.

message (channel, message)

Client will emit message for every message received that matches an active subscription.

clusterConfig

This event is emitted when a cluster config change has been detected. The cluster slot-node mapping table will be re-initialized, and the ready event will be emitted again once that is done.

cluster.createClient(port, host, options, [callback])

Create a new cluster instance. It will connect to the specified redis node and discover the rest of the nodes from there.

• port - defaults to 6379
• host - defaults to 127.0.0.1
• options - same as node_redis client options

cluster.Cluster(nodes, redisOptions, callback)

Create a new cluster instance. It will connect to the first available redis node and discover the rest of the nodes from there.

• nodes - an array of objects with host and port properties.
• redisOptions - node_redis client options. See node_redis documentation.

client.quit()

Cleanly end connections to all cluster nodes by sending the QUIT command after handling all replies.

client.getSlot(key)

Returns the slot which will be used for a key.

client.getConnectionBySlot(slot, callback)

Get the node_redis instance for a specific slot.