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redis - a node.js redis client =========================== [](https://travis-ci.org/NodeRedis/node_redis) [](https://coveralls.io/r/NodeRedis/node_redis?branch=) [](https://ci.appveyor.com/project/BridgeAR/node-redis/branch/master) [](https://gitter.im/NodeRedis/node_redis?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge) This is a complete and feature rich Redis client for node.js. __It supports all Redis commands__ and focuses on high performance. Install with: npm install redis ## Usage Example ```js var redis = require("redis"), client = redis.createClient(); // if you'd like to select database 3, instead of 0 (default), call // client.select(3, function() { /* ... */ }); client.on("error", function (err) { console.log("Error " + err); }); client.set("string key", "string val", redis.print); client.hset("hash key", "hashtest 1", "some value", redis.print); client.hset(["hash key", "hashtest 2", "some other value"], redis.print); client.hkeys("hash key", function (err, replies) { console.log(replies.length + " replies:"); replies.forEach(function (reply, i) { console.log(" " + i + ": " + reply); }); client.quit(); }); ``` This will display: mjr:~/work/node_redis (master)$ node example.js Reply: OK Reply: 0 Reply: 0 2 replies: 0: hashtest 1 1: hashtest 2 mjr:~/work/node_redis (master)$ Note that the API is entirely asynchronous. To get data back from the server, you'll need to use a callback. From v.2.6 on the API supports camelCase and snake_case and all options / variables / events etc. can be used either way. It is recommended to use camelCase as this is the default for the Node.js landscape. ### Promises You can also use node_redis with promises by promisifying node_redis with [bluebird](https://github.com/petkaantonov/bluebird) as in: ```js var redis = require('redis'); bluebird.promisifyAll(redis.RedisClient.prototype); bluebird.promisifyAll(redis.Multi.prototype); ``` It'll add a *Async* to all node_redis functions (e.g. return client.getAsync().then()) ```js // We expect a value 'foo': 'bar' to be present // So instead of writing client.get('foo', cb); you have to write: return client.getAsync('foo').then(function(res) { console.log(res); // => 'bar' }); // Using multi with promises looks like: return client.multi().get('foo').execAsync().then(function(res) { console.log(res); // => 'bar' }); ``` ### Sending Commands Each Redis command is exposed as a function on the `client` object. All functions take either an `args` Array plus optional `callback` Function or a variable number of individual arguments followed by an optional callback. Examples: ```js client.hmset(["key", "test keys 1", "test val 1", "test keys 2", "test val 2"], function (err, res) {}); // Works the same as client.hmset("key", ["test keys 1", "test val 1", "test keys 2", "test val 2"], function (err, res) {}); // Or client.hmset("key", "test keys 1", "test val 1", "test keys 2", "test val 2", function (err, res) {}); ``` Note that in either form the `callback` is optional: ```js client.set("some key", "some val"); client.set(["some other key", "some val"]); ``` If the key is missing, reply will be null. Only if the [Redis Command Reference](http://redis.io/commands) states something else it will not be null. ```js client.get("missingkey", function(err, reply) { // reply is null when the key is missing console.log(reply); }); ``` For a list of Redis commands, see [Redis Command Reference](http://redis.io/commands) Minimal parsing is done on the replies. Commands that return a integer return JavaScript Numbers, arrays return JavaScript Array. `HGETALL` returns an Object keyed by the hash keys. All strings will either be returned as string or as buffer depending on your setting. Please be aware that sending null, undefined and Boolean values will result in the value coerced to a string! # Redis Commands This library is a 1 to 1 mapping to [Redis commands](https://redis.io/commands). It is not a cache library so please refer to Redis commands page for full usage details. Example setting key to auto expire using [SET command](https://redis.io/commands/set) ```js // this key will expire after 10 seconds client.set('key', 'value!', 'EX', 10); ``` # API ## Connection and other Events `client` will emit some events about the state of the connection to the Redis server. ### "ready" `client` will emit `ready` once a connection is established. Commands issued before the `ready` event are queued, then replayed just before this event is emitted. ### "connect" `client` will emit `connect` as soon as the stream is connected to the server. ### "reconnecting" `client` will emit `reconnecting` when trying to reconnect to the Redis server after losing the connection. Listeners are passed an object containing `delay` (in ms) and `attempt` (the attempt #) attributes. ### "error" `client` will emit `error` when encountering an error connecting to the Redis server or when any other in node_redis occurs. If you use a command without callback and encounter a ReplyError it is going to be emitted to the error listener. So please attach the error listener to node_redis. ### "end" `client` will emit `end` when an established Redis server connection has closed. ### "drain" (deprecated) `client` will emit `drain` when the TCP connection to the Redis server has been buffering, but is now writable. This event can be used to stream commands in to Redis and adapt to backpressure. If the stream is buffering `client.should_buffer` is set to true. Otherwise the variable is always set to false. That way you can decide when to reduce your send rate and resume sending commands when you get `drain`. You can also check the return value of each command as it will also return the backpressure indicator (deprecated). If false is returned the stream had to buffer. ### "warning" `client` will emit `warning` when password was set but none is needed and if a deprecated option / function / similar is used. ### "idle" (deprecated) `client` will emit `idle` when there are no outstanding commands that are awaiting a response. ## redis.createClient() If you have `redis-server` running on the same machine as node, then the defaults for port and host are probably fine and you don't need to supply any arguments. `createClient()` returns a `RedisClient` object. Otherwise, `createClient()` accepts these arguments: * `redis.createClient([options])` * `redis.createClient(unix_socket[, options])` * `redis.createClient(redis_url[, options])` * `redis.createClient(port[, host][, options])` __Tip:__ If the Redis server runs on the same machine as the client consider using unix sockets if possible to increase throughput. #### `options` object properties | Property | Default | Description | |-----------|-----------|-------------| | host | 127.0.0.1 | IP address of the Redis server | | port | 6379 | Port of the Redis server | | path | null | The UNIX socket string of the Redis server | | url | null | The URL of the Redis server. Format: `[redis:]//[[user][:password@]][host][:port][/db-number][?db=db-number[&password=bar[&option=value]]]` (More info avaliable at [IANA](http://www.iana.org/assignments/uri-schemes/prov/redis)). | | parser | javascript | __Deprecated__ Use either the built-in JS parser [`javascript`]() or the native [`hiredis`]() parser. __Note__ `node_redis` < 2.6 uses hiredis as default if installed. This changed in v.2.6.0. | | string_numbers | null | Set to `true`, `node_redis` will return Redis number values as S