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NodeRedis
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Description

A high performance Node.js Redis client.

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Node Redis

A high performance Node.js Redis client.


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Installation

npm install redis

Usage

Example

const redis = require("redis");
const client = redis.createClient();

client.on("error", function(error) { console.error(error); });

client.set("key", "value", redis.print); client.get("key", redis.print);

Note that the API is entirely asynchronous. To get data back from the server, you'll need to use a callback.

Promises

Node Redis currently doesn't natively support promises (this is coming in v4), however you can wrap the methods you want to use with promises using the built-in Node.js

util.promisify
method on Node.js >= v8;
const { promisify } = require("util");
const getAsync = promisify(client.get).bind(client);

getAsync.then(console.log).catch(console.error);

Commands

This library is a 1 to 1 mapping of the Redis 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:
client.hmset(["key", "foo", "bar"], function(err, res) {
  // ...
});

// Works the same as client.hmset("key", ["foo", "bar"], function(err, res) { // ... });

// Or client.hmset("key", "foo", "bar", function(err, res) { // ... });

Care should be taken with user input if arrays are possible (via body-parser, query string or other method), as single arguments could be unintentionally interpreted as multiple args.

Note that in either form the

callback
is optional:
client.set("foo", "bar");
client.set(["hello", "world"]);

If the key is missing, reply will be null. Only if the Redis Command Reference states something else it will not be null.

client.get("missing_key", function(err, reply) {
  // reply is null when the key is missing
  console.log(reply);
});

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!

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 from the previous try) 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.

"warning"

client
will emit
warning
when password was set but none is needed and if a deprecated option / function / similar is used.

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.

Note: Using

'rediss://...
for the protocol in a
redis_url
will enable a TLS socket connection. However, additional TLS options will need to be passed in
options
, if required.

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[s]:]//[[user][:[email protected]]][host][:port][/db-number][?db=db-number[&password=bar[&option=value]]]
(More info avaliable at IANA). | | stringnumbers | null | Set to
true
, Node Redis will return Redis number values as Strings instead of javascript Numbers. Useful if you need to handle big numbers (above `Number.MAX
SAFEINTEGER === 2^53
). Hiredis is incapable of this behavior, so setting this option to
true
will result in the built-in javascript parser being used no matter the value of the
parser` option. | | return
buffers | false | If set to
true
, then all replies will be sent to callbacks as Buffers instead of Strings. | | detectbuffers | false | If set to
true
, then replies will be sent to callbacks as Buffers. This option lets you switch between Buffers and Strings on a per-command basis, whereas `return
buffers
applies to every command on a client. **Note**: This doesn't work properly with the pubsub mode. A subscriber has to either always return Strings or Buffers.                                                                                                                                                                                                                                   |
| socket_keepalive           | true      | If set to
true
, the keep-alive functionality is enabled on the underlying socket.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                           |
| socket_initial_delay       | 0         | Initial Delay in milliseconds, and this will also behave the interval keep alive message sending to Redis.                                                                                                                                                                                                                                                                                                                                                                                                                                                                    |
| no_ready_check             | false     | When a connection is established to the Redis server, the server might still be loading the database from disk. While loading, the server will not respond to any commands. To work around this, Node Redis has a "ready check" which sends the
INFO
command to the server. The response from the
INFO
command indicates whether the server is ready for more commands. When ready,
noderedis
emits a
ready
event. Setting
no
readycheck
to
true` will inhibit this check. | | enable
offlinequeue | true | By default, if there is no active connection to the Redis server, commands are added to a queue and are executed once the connection has been established. Setting `enableofflinequeue
to
false` will disable this feature and the callback will be executed immediately with an error, or an error will be emitted if no callback is specified. | | retry
unfulfilledcommands | false | If set to
true
, all commands that were unfulfilled while the connection is lost will be retried after the connection has been reestablished. Use this with caution if you use state altering commands (e.g.
incr
). This is especially useful if you use blocking commands. | | password | null | If set, client will run Redis auth command on connect. Alias `auth
pass
**Note** Node Redis < 2.5 must use
authpass
|
| db                         | null      | If set, client will run Redis
select` command on connect. | | family | IPv4 | You can force using IPv6 if you set the family to 'IPv6'. See Node.js net or dns modules on how to use the family type. | | disable
resubscribing | false | If set to
true
, a client won't resubscribe after disconnecting. | | renamecommands | null | Passing an object with renamed commands to use instead of the original functions. For example, if you renamed the command KEYS to "DO-NOT-USE" then the renamecommands object would be:
{ KEYS : "DO-NOT-USE" }
. See the Redis security topics for more info. | | tls | null | An object containing options to pass to tls.connect to set up a TLS connection to Redis (if, for example, it is set up to be accessible via a tunnel). | | prefix | null | A string used to prefix all used keys (e.g.
namespace:test
). Please be aware that the
keys
command will not be prefixed. The
keys
command has a "pattern" as argument and no key and it would be impossible to determine the existing keys in Redis if this would be prefixed. | | retrystrategy | function | A function that receives an options object as parameter including the retry
attempt
, the `total
retrytime
indicating how much time passed since the last time connected, the
error
why the connection was lost and the number of
times
connected` in total. If you return a number from this function, the retry will happen exactly after that time in milliseconds. If you return a non-number, no further retry will happen and all offline commands are flushed with errors. Return an error to return that specific error to all offline commands. Example below. |

detect_buffers
example:

const redis = require("redis");
const client = redis.createClient({ detect_buffers: true });

client.set("foo_rand000000000000", "OK");

// This will return a JavaScript String client.get("foo_rand000000000000", function(err, reply) { console.log(reply.toString()); // Will print OK });

// This will return a Buffer since original key is specified as a Buffer client.get(new Buffer("foo_rand000000000000"), function(err, reply) { console.log(reply.toString()); // Will print <buffer> });

retry_strategy
example:

const client = redis.createClient({
  retry_strategy: function(options) {
    if (options.error && options.error.code === "ECONNREFUSED") {
      // End reconnecting on a specific error and flush all commands with
      // a individual error
      return new Error("The server refused the connection");
    }
    if (options.total_retry_time > 1000 * 60 * 60) {
      // End reconnecting after a specific timeout and flush all commands
      // with a individual error
      return new Error("Retry time exhausted");
    }
    if (options.attempt > 10) {
      // End reconnecting with built in error
      return undefined;
    }
    // reconnect after
    return Math.min(options.attempt * 100, 3000);
  },
});

client.auth(password[, callback])

When connecting to a Redis server that requires authentication, the

AUTH
command must be sent as the first command after connecting. This can be tricky to coordinate with reconnections, the ready check, etc. To make this easier,
client.auth()
stashes
password
and will send it after each connection, including reconnections.
callback
is invoked only once, after the response to the very first
AUTH
command sent. NOTE: Your call to
client.auth()
should not be inside the ready handler. If you are doing this wrong,
client
will emit an error that looks something like this
Error: Ready check failed: ERR operation not permitted
.

client.quit(callback)

This sends the quit command to the redis server and ends cleanly right after all running commands were properly handled. If this is called while reconnecting (and therefore no connection to the redis server exists) it is going to end the connection right away instead of resulting in further reconnections! All offline commands are going to be flushed with an error in that case.

client.end(flush)

Forcibly close the connection to the Redis server. Note that this does not wait until all replies have been parsed. If you want to exit cleanly, call

client.quit()
as mentioned above.

You should set flush to true, if you are not absolutely sure you do not care about any other commands. If you set flush to false all still running commands will silently fail.

This example closes the connection to the Redis server before the replies have been read. You probably don't want to do this:

const redis = require("redis");
const client = redis.createClient();

client.set("hello", "world", function(err) { // This will either result in an error (flush parameter is set to true) // or will silently fail and this callback will not be called at all (flush set to false) console.error(err); });

// No further commands will be processed client.end(true);

client.get("hello", function(err) { console.error(err); // => 'The connection has already been closed.' });

client.end()
without the flush parameter set to true should NOT be used in production!

Error Handling

Currently the following

Error
subclasses exist:
  • RedisError
    : All errors returned by the client
  • ReplyError
    subclass of
    RedisError
    : All errors returned by Redis itself
  • AbortError
    subclass of
    RedisError
    : All commands that could not finish due to what ever reason
  • ParserError
    subclass of
    RedisError
    : Returned in case of a parser error (this should not happen)
  • AggregateError
    subclass of
    AbortError
    : Emitted in case multiple unresolved commands without callback got rejected in debug_mode instead of lots of
    AbortError
    s.

All error classes are exported by the module.

Example

const assert = require("assert");

const redis = require("redis"); const { AbortError, AggregateError, ReplyError } = require("redis");

const client = redis.createClient();

client.on("error", function(err) { assert(err instanceof Error); assert(err instanceof AbortError); assert(err instanceof AggregateError);

// The set and get are aggregated in here assert.strictEqual(err.errors.length, 2); assert.strictEqual(err.code, "NR_CLOSED"); });

client.set("foo", "bar", "baz", function(err, res) { // Too many arguments assert(err instanceof ReplyError); // => true assert.strictEqual(err.command, "SET"); assert.deepStrictEqual(err.args, ["foo", 123, "bar"]);

redis.debug_mode = true;

client.set("foo", "bar"); client.get("foo");

process.nextTick(function() { // Force closing the connection while the command did not yet return client.end(true); redis.debug_mode = false; }); });

Every

ReplyError
contains the
command
name in all-caps and the arguments (
args
).

If Node Redis emits a library error because of another error, the triggering error is added to the returned error as

origin
attribute.

Error codes

Node Redis returns a

NR_CLOSED
error code if the clients connection dropped. If a command unresolved command got rejected a
UNCERTAIN_STATE
code is returned. A
CONNECTION_BROKEN
error code is used in case Node Redis gives up to reconnect.

client.unref()

Call

unref()
on the underlying socket connection to the Redis server, allowing the program to exit once no more commands are pending.

This is an experimental feature, and only supports a subset of the Redis protocol. Any commands where client state is saved on the Redis server, e.g.

*SUBSCRIBE
or the blocking
BL*
commands will NOT work with
.unref()
.
const redis = require("redis");
const client = redis.createClient();

/*

  • Calling unref() will allow this program to exit immediately after the get
  • command finishes. Otherwise the client would hang as long as the
  • client-server connection is alive.
  • / client.unref();

client.get("foo", function(err, value) { if (err) throw err; console.log(value); });

Hash Commands

Most Redis commands take a single String or an Array of Strings as arguments, and replies are sent back as a single String or an Array of Strings. When dealing with hash values, there are a couple of useful exceptions to this.

client.hgetall(hash, callback)

The reply from an

HGETALL
command will be converted into a JavaScript Object. That way you can interact with the responses using JavaScript syntax.

Example:

client.hmset("key", "foo", "bar", "hello", "world");

client.hgetall("hosts", function(err, value) { console.log(value.foo); // > "bar" console.log(value.hello); // > "world" });

client.hmset(hash, key1, val1, ...keyN, valN, [callback])

Multiple values may also be set by supplying more arguments.

Example:

//  key
//    1) foo   => bar
//    2) hello => world
client.HMSET("key", "foo", "bar", "hello", "world");

PubSub

Example

This example opens two client connections, subscribes to a channel on one of them, and publishes to that channel on the other.

const redis = require("redis");

const subscriber = redis.createClient(); const publisher = redis.createClient();

let messageCount = 0;

subscriber.on("subscribe", function(channel, count) { publisher.publish("a channel", "a message"); publisher.publish("a channel", "another message"); });

subscriber.on("message", function(channel, message) { messageCount += 1;

console.log("Subscriber received message in channel '" + channel + "': " + message);

if (messageCount === 2) { subscriber.unsubscribe(); subscriber.quit(); publisher.quit(); } });

subscriber.subscribe("a channel");

When a client issues a

SUBSCRIBE
or
PSUBSCRIBE
, that connection is put into a
"subscriber"
mode. At that point, the only valid commands are those that modify the subscription set, and quit (also ping on some redis versions). When the subscription set is empty, the connection is put back into regular mode.

If you need to send regular commands to Redis while in subscriber mode, just open another connection with a new client (use

client.duplicate()
to quickly duplicate an existing client).

Subscriber Events

If a client has subscriptions active, it may emit these events:

"message" (channel, message):

Client will emit

message
for every message received that matches an active subscription. Listeners are passed the channel name as
channel
and the message as
message
.

"pmessage" (pattern, channel, message):

Client will emit

pmessage
for every message received that matches an active subscription pattern. Listeners are passed the original pattern used with
PSUBSCRIBE
as
pattern
, the sending channel name as
channel
, and the message as
message
.

"message_buffer" (channel, message):

This is the same as the

message
event with the exception, that it is always going to emit a buffer. If you listen to the
message
event at the same time as the
message_buffer
, it is always going to emit a string.

"pmessage_buffer" (pattern, channel, message):

This is the same as the

pmessage
event with the exception, that it is always going to emit a buffer. If you listen to the
pmessage
event at the same time as the
pmessage_buffer
, it is always going to emit a string.

"subscribe" (channel, count):

Client will emit

subscribe
in response to a
SUBSCRIBE
command. Listeners are passed the channel name as
channel
and the new count of subscriptions for this client as
count
.

"psubscribe" (pattern, count):

Client will emit

psubscribe
in response to a
PSUBSCRIBE
command. Listeners are passed the original pattern as
pattern
, and the new count of subscriptions for this client as
count
.

"unsubscribe" (channel, count):

Client will emit

unsubscribe
in response to a
UNSUBSCRIBE
command. Listeners are passed the channel name as
channel
and the new count of subscriptions for this client as
count
. When
count
is 0, this client has left subscriber mode and no more subscriber events will be emitted.

"punsubscribe" (pattern, count):

Client will emit

punsubscribe
in response to a
PUNSUBSCRIBE
command. Listeners are passed the channel name as
channel
and the new count of subscriptions for this client as
count
. When
count
is 0, this client has left subscriber mode and no more subscriber events will be emitted.

client.multi([commands])

MULTI
commands are queued up until an
EXEC
is issued, and then all commands are run atomically by Redis. The interface returns an individual
Multi
object by calling
client.multi()
. If any command fails to queue, all commands are rolled back and none is going to be executed (For further information see the Redis transactions documentation).
const redis = require("redis");
const client = redis.createClient();

let setSize = 20;

client.sadd("key", "member1"); client.sadd("key", "member2");

while (setSize > 0) { client.sadd("key", "member" + setSize); setSize -= 1; }

// chain commands client .multi() .scard("key") .smembers("key") .keys("*") .dbsize() .exec(function(err, replies) { console.log("MULTI got " + replies.length + " replies"); replies.forEach(function(reply, index) { console.log("REPLY @ index " + index + ": " + reply.toString()); }); });

Multi.exec([callback])

client.multi()
is a constructor that returns a
Multi
object.
Multi
objects share all of the same command methods as
client
objects do. Commands are queued up inside the
Multi
object until
Multi.exec()
is invoked.

If your code contains an syntax error an

EXECABORT
error is going to be thrown and all commands are going to be aborted. That error contains a
.errors
property that contains the concrete errors. If all commands were queued successfully and an error is thrown by redis while processing the commands that error is going to be returned in the result array! No other command is going to be aborted though than the ones failing.

You can either chain together

MULTI
commands as in the above example, or you can queue individual commands while still sending regular client command as in this example:
const redis = require("redis");
const client = redis.createClient();

// start a separate multi command queue const multi = client.multi();

// add some commands to the queue multi.incr("count_cats", redis.print); multi.incr("count_dogs", redis.print);

// runs a command immediately outside of the multi instance client.mset("count_cats", 100, "count_dogs", 50, redis.print);

// drains the multi queue and runs each command atomically multi.exec(function(err, replies) { console.log(replies); // 101, 51 });

In addition to adding commands to the

MULTI
queue individually, you can also pass an array of commands and arguments to the constructor:
const redis = require("redis");

const client = redis.createClient();

client .multi([ ["mget", "foo", "bar", redis.print], ["incr", "hello"], ]) .exec(function(err, replies) { console.log(replies); });

Multi.exec_atomic([callback])

Identical to Multi.exec but with the difference that executing a single command will not use transactions.

Optimistic Locks

Using

multi
you can make sure your modifications run as a transaction, but you can't be sure you got there first. What if another client modified a key while you were working with it's data?

To solve this, Redis supports the WATCH command, which is meant to be used with MULTI:

const redis = require("redis");

const client = redis.createClient();

client.watch("foo", function(watchError) { if (watchError) throw watchError;

client.get("foo", function(getError, result) { if (getError) throw getError;

// Process result
// Heavy and time consuming operation here to generate "bar"

client
  .multi()
  .set("foo", "bar")
  .exec(function(execError, results) {
    /**
     * If err is null, it means Redis successfully attempted
     * the operation.
     */
    if (execError) throw err;

    /**
     * If results === null, it means that a concurrent client
     * changed the key while we were processing it and thus
     * the execution of the MULTI command was not performed.
     *
     * NOTICE: Failing an execution of MULTI is not considered
     * an error. So you will have err === null and results === null
     */
  });

}); });

The above snippet shows the correct usage of

watch
with
multi
. Every time a watched key is changed before the execution of a
multi
command, the execution will return
null
. On a normal situation, the execution will return an array of values with the results of the operations.

As stated in the snippet, failing the execution of a

multi
command being watched is not considered an error. The execution may return an error if, for example, the client cannot connect to Redis.

An example where we can see the execution of a

multi
command fail is as follows:
const clients = {
  watcher: redis.createClient(),
  modifier: redis.createClient(),
};

clients.watcher.watch("foo", function(watchError) { if (watchError) throw watchError;

// if you comment out the next line, the transaction will work clients.modifier.set("foo", Math.random(), setError => { if (setError) throw err; });

// using a setTimeout here to ensure that the MULTI/EXEC will come after the SET. // Normally, you would use a callback to ensure order, but I want the above SET command // to be easily comment-out-able. setTimeout(function() { clients.watcher .multi() .set("foo", "bar") .set("hello", "world") .exec((multiExecError, results) => { if (multiExecError) throw multiExecError;

    if (results === null) {
      console.log("transaction aborted because results were null");
    } else {
      console.log("transaction worked and returned", results);
    }

    clients.watcher.quit();
    clients.modifier.quit();
  });

}, 1000); });

WATCH
limitations

Redis WATCH works only on whole key values. For example, with WATCH you can watch a hash for modifications, but you cannot watch a specific field of a hash.

The following example would watch the keys

foo
and
hello
, not the field
hello
of hash
foo
:
const redis = require("redis");

const client = redis.createClient();

client.hget("foo", "hello", function(hashGetError, result) { if (hashGetError) throw hashGetError;

//Do some processing with the value from this field and watch it after

client.watch("foo", "hello", function(watchError) { if (watchError) throw watchError;

/**
 * This is now watching the keys 'foo' and 'hello'. It is not
 * watching the field 'hello' of hash 'foo'. Because the key 'foo'
 * refers to a hash, this command is now watching the entire hash
 * for modifications.
 */

}); });

This limitation also applies to sets (you can not watch individual set members) and any other collections.

client.batch([commands])

Identical to

.multi()
without transactions. This is recommended if you want to execute many commands at once but don't need to rely on transactions.

BATCH
commands are queued up until an
EXEC
is issued, and then all commands are run atomically by Redis. The interface returns an individual
Batch
object by calling
client.batch()
. The only difference between .batch and .multi is that no transaction is going to be used. Be aware that the errors are - just like in multi statements - in the result. Otherwise both, errors and results could be returned at the same time.

If you fire many commands at once this is going to boost the execution speed significantly compared to firing the same commands in a loop without waiting for the result! See the benchmarks for further comparison. Please remember that all commands are kept in memory until they are fired.

Monitor mode

Redis supports the

MONITOR
command, which lets you see all commands received by the Redis server across all client connections, including from other client libraries and other computers.

A

monitor
event is going to be emitted for every command fired from any client connected to the server including the monitoring client itself. The callback for the
monitor
event takes a timestamp from the Redis server, an array of command arguments and the raw monitoring string.

Example:

const redis = require("redis");
const client = redis.createClient();

client.monitor(function(err, res) { console.log("Entering monitoring mode."); });

client.set("foo", "bar");

client.on("monitor", function(time, args, rawReply) { console.log(time + ": " + args); // 1458910076.446514:['set', 'foo', 'bar'] });

Extras

Some other things you might find useful.

client.server_info

After the ready probe completes, the results from the INFO command are saved in the

client.server_info
object.

The

versions
key contains an array of the elements of the version string for easy comparison.
> client.server_info.redis_version
'2.3.0'
> client.server_info.versions
[ 2, 3, 0 ]

redis.print()

A handy callback function for displaying return values when testing. Example:

const redis = require("redis");
const client = redis.createClient();

client.on("connect", function() { client.set("foo", "bar", redis.print); // => "Reply: OK" client.get("foo", redis.print); // => "Reply: bar" client.quit(); });

Multi-word commands

To execute redis multi-word commands like

SCRIPT LOAD
or
CLIENT LIST
pass the second word as first parameter:
client.script("load", "return 1");

client .multi() .script("load", "return 1") .exec();

client.multi([["script", "load", "return 1"]]).exec();

client.duplicate([options][, callback])

Duplicate all current options and return a new redisClient instance. All options passed to the duplicate function are going to replace the original option. If you pass a callback, duplicate is going to wait until the client is ready and returns it in the callback. If an error occurs in the meanwhile, that is going to return an error instead in the callback.

One example of when to use duplicate() would be to accommodate the connection- blocking redis commands

BRPOP
,
BLPOP
, and
BRPOPLPUSH
. If these commands are used on the same Redis client instance as non-blocking commands, the non-blocking ones may be queued up until after the blocking ones finish.

Another reason to use duplicate() is when multiple DBs on the same server are accessed via the redis SELECT command. Each DB could use its own connection.

client.send_command(command_name[, [args][, callback]])

All Redis commands have been added to the

client
object. However, if new commands are introduced before this library is updated or if you want to add individual commands you can use
send_command()
to send arbitrary commands to Redis.

All commands are sent as multi-bulk commands.

args
can either be an Array of arguments, or omitted / set to undefined.

redis.add_command(command_name)

Calling add_command will add a new command to the prototype. The exact command name will be used when calling using this new command. Using arbitrary arguments is possible as with any other command.

client.connected

Boolean tracking the state of the connection to the Redis server.

client.command_queue_length

The number of commands that have been sent to the Redis server but not yet replied to. You can use this to enforce some kind of maximum queue depth for commands while connected.

client.offline_queue_length

The number of commands that have been queued up for a future connection. You can use this to enforce some kind of maximum queue depth for pre-connection commands.

Commands with Optional and Keyword arguments

This applies to anything that uses an optional

[WITHSCORES]
or
[LIMIT offset count]
in the redis.io/commands documentation.

Example

const args = ["myzset", 1, "one", 2, "two", 3, "three", 99, "ninety-nine"];

client.zadd(args, function(addError, addResponse) { if (addError) throw addError; console.log("added " + addResponse + " items.");

// -Infinity and +Infinity also work const args1 = ["myzset", "+inf", "-inf"]; client.zrevrangebyscore(args1, function(rangeError, rangeResponse) { if (rangeError) throw rangeError; console.log("response1", rangeResponse); // ... });

const max = 3; const min = 1; const offset = 1; const count = 2; const args2 = ["myzset", max, min, "WITHSCORES", "LIMIT", offset, count]; client.zrevrangebyscore(args2, function(rangeError, rangeResponse) { if (rangeError) throw rangeError; console.log("response2", rangeResponse); // ... }); });

Performance

Much effort has been spent to make Node Redis as fast as possible for common operations.

Mac mini (2018), i7-3.2GHz and 32gb memory
clients: 1, NodeJS: 12.15.0, Redis: 5.0.6, parser: javascript, connected by: tcp
         PING,         1/1 avg/max:   0.03/  3.28 2501ms total,   31926 ops/sec
         PING,  batch 50/1 avg/max:   0.08/  3.35 2501ms total,  599460 ops/sec
   SET 4B str,         1/1 avg/max:   0.03/  3.54 2501ms total,   29483 ops/sec
   SET 4B str,  batch 50/1 avg/max:   0.10/  1.39 2501ms total,  477689 ops/sec
   SET 4B buf,         1/1 avg/max:   0.04/  1.52 2501ms total,   23449 ops/sec
   SET 4B buf,  batch 50/1 avg/max:   0.20/  2.09 2501ms total,  244382 ops/sec
   GET 4B str,         1/1 avg/max:   0.03/  1.35 2501ms total,   32205 ops/sec
   GET 4B str,  batch 50/1 avg/max:   0.09/  2.02 2501ms total,  568992 ops/sec
   GET 4B buf,         1/1 avg/max:   0.03/  2.93 2501ms total,   32802 ops/sec
   GET 4B buf,  batch 50/1 avg/max:   0.08/  1.03 2501ms total,  592863 ops/sec
 SET 4KiB str,         1/1 avg/max:   0.03/  0.76 2501ms total,   29287 ops/sec
 SET 4KiB str,  batch 50/1 avg/max:   0.35/  2.97 2501ms total,  143163 ops/sec
 SET 4KiB buf,         1/1 avg/max:   0.04/  1.21 2501ms total,   23070 ops/sec
 SET 4KiB buf,  batch 50/1 avg/max:   0.28/  2.34 2501ms total,  176809 ops/sec
 GET 4KiB str,         1/1 avg/max:   0.03/  1.54 2501ms total,   29555 ops/sec
 GET 4KiB str,  batch 50/1 avg/max:   0.18/  1.59 2501ms total,  279188 ops/sec
 GET 4KiB buf,         1/1 avg/max:   0.03/  1.80 2501ms total,   30681 ops/sec
 GET 4KiB buf,  batch 50/1 avg/max:   0.17/  5.00 2501ms total,  285886 ops/sec
         INCR,         1/1 avg/max:   0.03/  1.99 2501ms total,   32757 ops/sec
         INCR,  batch 50/1 avg/max:   0.09/  2.54 2501ms total,  538964 ops/sec
        LPUSH,         1/1 avg/max:   0.05/  4.85 2501ms total,   19482 ops/sec
        LPUSH,  batch 50/1 avg/max:   0.12/  9.52 2501ms total,  395562 ops/sec
    LRANGE 10,         1/1 avg/max:   0.06/  9.21 2501ms total,   17062 ops/sec
    LRANGE 10,  batch 50/1 avg/max:   0.22/  1.03 2501ms total,  228269 ops/sec
   LRANGE 100,         1/1 avg/max:   0.05/  1.44 2501ms total,   19051 ops/sec
   LRANGE 100,  batch 50/1 avg/max:   0.99/  3.46 2501ms total,   50480 ops/sec
 SET 4MiB str,         1/1 avg/max:   4.11/ 13.96 2501ms total,     243 ops/sec
 SET 4MiB str,  batch 20/1 avg/max:  91.16/145.01 2553ms total,     219 ops/sec
 SET 4MiB buf,         1/1 avg/max:   2.81/ 11.90 2502ms total,     354 ops/sec
 SET 4MiB buf,  batch 20/1 avg/max:  36.21/ 70.96 2535ms total,     552 ops/sec
 GET 4MiB str,         1/1 avg/max:   2.82/ 19.10 2503ms total,     354 ops/sec
 GET 4MiB str,  batch 20/1 avg/max: 128.57/207.86 2572ms total,     156 ops/sec
 GET 4MiB buf,         1/1 avg/max:   3.13/ 23.88 2501ms total,     318 ops/sec
 GET 4MiB buf,  batch 20/1 avg/max:  65.91/ 87.59 2572ms total,     303 ops/sec

Debugging

To get debug output run your Node Redis application with

NODE_DEBUG=redis
.

This is also going to result in good stack traces opposed to useless ones otherwise for any async operation. If you only want to have good stack traces but not the debug output run your application in development mode instead (

NODE_ENV=development
).

Good stack traces are only activated in development and debug mode as this results in a significant performance penalty.

Comparison:

Standard stack trace:

ReplyError: ERR wrong number of arguments for 'set' command
    at parseError (/home/ruben/repos/redis/node_modules/redis-parser/lib/parser.js:158:12)
    at parseType (/home/ruben/repos/redis/node_modules/redis-parser/lib/parser.js:219:14)

Debug stack trace:

ReplyError: ERR wrong number of arguments for 'set' command
    at new Command (/home/ruben/repos/redis/lib/command.js:9:902)
    at RedisClient.set (/home/ruben/repos/redis/lib/commands.js:9:3238)
    at Context. (/home/ruben/repos/redis/test/good_stacks.spec.js:20:20)
    at callFnAsync (/home/ruben/repos/redis/node_modules/mocha/lib/runnable.js:349:8)
    at Test.Runnable.run (/home/ruben/repos/redis/node_modules/mocha/lib/runnable.js:301:7)
    at Runner.runTest (/home/ruben/repos/redis/node_modules/mocha/lib/runner.js:422:10)
    at /home/ruben/repos/redis/node_modules/mocha/lib/runner.js:528:12
    at next (/home/ruben/repos/redis/node_modules/mocha/lib/runner.js:342:14)
    at /home/ruben/repos/redis/node_modules/mocha/lib/runner.js:352:7
    at next (/home/ruben/repos/redis/node_modules/mocha/lib/runner.js:284:14)
    at Immediate._onImmediate (/home/ruben/repos/redis/node_modules/mocha/lib/runner.js:320:5)
    at processImmediate [as _immediateCallback] (timers.js:383:17)

Contributing

Please see the contributing guide.

License

This repository is licensed under the "MIT" license. See LICENSE.

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