Redis sentinel client for nodejs


Wrapper around node_redis creating a client pointing at the master server which autoupdates when the master goes down.

var sentinel = require('redis-sentinel');
// List the sentinel endpoints 
var endpoints = [
    {host: '', port: 26379},
    {host: '', port: 26380}
var opts = {}; // Standard node_redis client options 
var masterName = 'mymaster';
// masterName and opts are optional - masterName defaults to 'mymaster' 
var redisClient = sentinel.createClient(endpoints, masterName, opts);
// redisClient is a normal redis client, except that if the master goes down 
// it will keep checking the sentinels for a new master and then connect to that. 
// No need to monitor for reconnects etc - everything handled transparently 
// Anything that persists over the normal node_redis reconnect will persist here.  
// Anything that doesn't, won't. 
// An equivalent way of doing the above (if you don't want to have to pass the endpoints around all the time) is 
var Sentinel = sentinel.Sentinel(endpoints);
var masterClient = Sentinel.createClient(masterName, opts);

You can get a connection to a slave (chosen at random) or the first available sentinel from the endpoints by passing in the role attribute in the options. E.g.

// The master is the default case if no role is specified. 
var masterClient = sentinel.createClient(endpoints, masterName, {role: 'master'}); 
var slaveClient = sentinel.createClient(endpoints, masterName, {role: 'slave'});
var sentinelClient = sentinel.createClient(endpoints, {role: 'sentinel'});

Where you should also transparently get a reconnection to a new slave/sentinel if the existing one goes down.

  • We could probably be cleverer with reconnects etc. and there may be issues with the error handling