# Node-Redis
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node-redis is a modern, high performance [Redis](https://redis.io) client for Node.js.
## Packages
| Name | Description |
|----------------------------------------------|--------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------|
| [redis](./) | [](https://www.npmjs.com/package/redis) [](https://www.npmjs.com/package/redis) |
| [@redis/client](./packages/client) | [](https://www.npmjs.com/package/@redis/client) [](https://www.npmjs.com/package/@redis/client) [](https://redis.js.org/documentation/client/) |
| [@redis/bloom](./packages/bloom) | [](https://www.npmjs.com/package/@redis/bloom) [](https://www.npmjs.com/package/@redis/bloom) [](https://redis.js.org/documentation/bloom/) [Redis Bloom](https://oss.redis.com/redisbloom/) commands |
| [@redis/graph](./packages/graph) | [](https://www.npmjs.com/package/@redis/graph) [](https://www.npmjs.com/package/@redis/graph) [](https://redis.js.org/documentation/graph/) [Redis Graph](https://oss.redis.com/redisgraph/) commands |
| [@redis/json](./packages/json) | [](https://www.npmjs.com/package/@redis/json) [](https://www.npmjs.com/package/@redis/json) [](https://redis.js.org/documentation/json/) [Redis JSON](https://oss.redis.com/redisjson/) commands |
| [@redis/search](./packages/search) | [](https://www.npmjs.com/package/@redis/search) [](https://www.npmjs.com/package/@redis/search) [](https://redis.js.org/documentation/search/) [RediSearch](https://oss.redis.com/redisearch/) commands |
| [@redis/time-series](./packages/time-series) | [](https://www.npmjs.com/package/@redis/time-series) [](https://www.npmjs.com/package/@redis/time-series) [](https://redis.js.org/documentation/time-series/) [Redis Time-Series](https://oss.redis.com/redistimeseries/) commands |
> :warning: In version 4.1.0 we moved our subpackages from `@node-redis` to `@redis`. If you're just using `npm install redis`, you don't need to do anything—it'll upgrade automatically. If you're using the subpackages directly, you'll need to point to the new scope (e.g. `@redis/client` instead of `@node-redis/client`).
## Installation
Start a redis via docker:
``` bash
docker run -p 6379:6379 -it redis/redis-stack-server:latest
```
To install node-redis, simply:
```bash
npm install redis
```
> :warning: The new interface is clean and cool, but if you have an existing codebase, you'll want to read the [migration guide](./docs/v3-to-v4.md).
Looking for a high-level library to handle object mapping? See [redis-om-node](https://github.com/redis/redis-om-node)!
## Usage
### Basic Example
```typescript
import { createClient } from 'redis';
const client = createClient();
client.on('error', err => console.log('Redis Client Error', err));
await client.connect();
await client.set('key', 'value');
const value = await client.get('key');
await client.disconnect();
```
The above code connects to localhost on port 6379. To connect to a different host or port, use a connection string in the format `redis[s]://[[username][:password]@][host][:port][/db-number]`:
```typescript
createClient({
url: 'redis://alice:foobared@awesome.redis.server:6380'
});
```
You can also use discrete parameters, UNIX sockets, and even TLS to connect. Details can be found in the [client configuration guide](./docs/client-configuration.md).
To check if the the client is connected and ready to send commands, use `client.isReady` which returns a boolean. `client.isOpen` is also available. This returns `true` when the client's underlying socket is open, and `false` when it isn't (for example when the client is still connecting or reconnecting after a network error).
### Redis Commands
There is built-in support for all of the [out-of-the-box Redis commands](https://redis.io/commands). They are exposed using the raw Redis command names (`HSET`, `HGETALL`, etc.) and a friendlier camel-cased version (`hSet`, `hGetAll`, etc.):
```typescript
// raw Redis commands
await client.HSET('key', 'field', 'value');
await client.HGETALL('key');
// friendly JavaScript commands
await client.hSet('key', 'field', 'value');
await client.hGetAll('key');
```
Modifiers to commands are specified using a JavaScript object:
```typescript
await client.set('key', 'value', {
EX: 10,
NX: true
});
```
Replies will be transformed into useful data structures:
```typescript
await client.hGetAll('key'); // { field1: 'value1', field2: 'value2' }
await client.hVals('key'); // ['value1', 'value2']
```
`Buffer`s are supported as well:
```typescript
await client.hSet('key', 'field', Buffer.from('value')); // 'OK'
await client.hGetAll(
commandOptions({ returnBuffers: true }),
'key'
); // { field: <Buffer 76 61 6c 75 65> }
```
### Unsupported Redis Commands
If you want to run commands and/or use arguments that Node Redis doesn't know about (yet!) use `.sendCommand()`:
```typescript
await client.sendCommand(['SET', 'key', 'value', 'NX']); // 'OK'
await client.sendCommand(['HGETALL', 'key']); // ['key1', 'field1', 'key2', 'field2']
```
### Transactions (Multi/Exec)
Start a [transaction](https://redis.io/topics/transactions) by calling `.multi()`, then chaining your commands. When you're done, call `.exec()` and you'll get an array back with your results:
```typescript
await client.set('another-key', 'another-value');
const [setKeyReply, otherKeyValue] = await client
.multi()
.set('key', 'value')
.get('another-key')
.exec(); // ['OK', 'another-value']
```
You can also [watch](https://redis.io/topics/transactions#optimistic-locking-using-check-and-set) keys by calling `.watch()`. Your transaction will abort if any of the watched keys change.
To dig deeper into transactions, check out the [Isolated Execution Guide](./docs/isolated-execution.md).
### Blocking Commands
Any command can be run on a new connection by specifying the `isolated` option. The newly created connection is closed when the command's `Promise` is fulfilled.
This pattern works especially well for blocking commands—such as `BLPOP` and `BLMOVE`:
```typescript
import { commandOptions } from 'redis';
const blPopPromise = client.blPop(
commandOptions({ isolated: true }),
'key',
0
);
await client.lPush('key', ['1', '2']);
await blPopPromise; // '2'
```
To learn more about isolated execution, check out the [guide](./docs/isolated-execution.md).
### Pub/Sub
See the [Pub/Sub overview](./docs/pub-sub.md).
### Scan Iterator
[`SCAN`](https://redis.io/commands/scan) results can be looped over using [async iterators](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Symbol/asyncIterator):
```typescript
for await (const key of client.scanIterator()) {
// use the key!
await client.get(key);
}
```
This works with `HSCAN`, `SSCAN`, and `ZSCAN` too:
```typescript
for await (const { field, value } of client.hScanIterator('hash')) {}
for await (const member of client.sScanIterator('set')) {}
for await (const { score, value } of client.zScanIterator('sorted-set')) {}
```
You can override the default options by providing a configuration object:
```typescript
client.scanIterator({
TYPE: 'string', // `SCAN` only
MATCH: 'patter*',
COUNT: 100
});
```
### [Programmability](https://redis.io/docs/manual/programmability/)
Redis provides a programming interface allowing code execution on the redis server.
#### [Functions](https://redis.io/docs/manual/programmability/functions-intro/)
The following example retrieves a key in redis, returning the value of the key, incremented by an integer. For example, if your key _foo_ has the value _17_ and we run `add('foo', 25)`, it returns the answer to Life, the Universe and Everything.
```lua
#!lua name=library
redis.register_function {
function_name = 'add',
callback = function(keys, args) return redis.call('GET', keys[1]) + args[1] end,
flags = { 'no-writes' }
}
```
Here is the same example, but in a format that can be pasted into the `redis-cli`.
```
FUNCTION LOAD "#!lua name=library\nredis.register_function{function_name=\"add\", callback=function(keys, args) return redis.call('GET', keys[1])+args[1] end, flags={\"no-writes\"}}"
```
Load the prior redis function on the _redis server_ before running the example below.
```typescript
import { createClient } from 'redis';
const client = createClient({
functions: {
library: {
add: {
NUMBER_OF_KEYS: 1,
transformArguments(key: string, toAdd: number): Array<string> {
return [key, toAdd.toString()];
},
transformReply(reply: number): number {
return reply;
}
}
}
}
});
await client.connect();
await client.set('key', '1');
await client.library.add('key', 2); // 3
```
#### [Lua Scripts](https://redis.io/docs/manual/programmability/eval-intro/)
The following is an end-to-end example of the prior concept.
```typescript
import { createClient, defineScript } from 'redis';
const client = createClient({
scripts: {
add: defineScript({
NUMBER_OF_KEYS: 1,
SCRIPT:
'return redis.call("GET", KEYS[1]) + ARGV[1];',
transformArguments(key: string, toAdd: number): Array<string> {
return [key, toAdd.toString()];
},
transformReply(reply: number): number {
return reply;
}
})
}
});
await client.connect();
await client.set('key', '1');
await client.add('key', 2); // 3
```
### Disconnecting
There are two functions that disconnect a client from the Redis server. In most scenarios you should use `.quit()` to ensure that pending commands are sent to Redis before closing a connection.
#### `.QUIT()`/`.quit()`
Gracefully close a client's connection to Redis, by sending the [`QUIT`](https://redis.io/commands/quit) command to the server. Before quitting, the client executes any remaining commands in its queue, and will receive replies from Redis for each of them.
```typescript
const [ping, get, quit] = await Promise.all([
client.ping(),
client.get('key'),
client.quit()
]); // ['PONG', null, 'OK']
try {
await client.get('key');
} catch (err) {
// ClosedClient Error
}
```
#### `.disconnect()`
Forcibly close a client's connection to Redis immediately. Calling `disconnect` will not send further pending commands to the Redis server, or wait for or parse outstanding responses.
```typescript
await client.disconnect();
```
### Auto-Pipelining
Node Redis will automatically pipeline requests that are made during the same "tick".
```typescript
client.set('Tm9kZSBSZWRpcw==', 'users:1');
client.sAdd('users:1:tokens', 'Tm9kZSBSZWRpcw==');
```
Of course, if you don't do something with your Promises you're certain to get [unhandled Promise exceptions](https://nodejs.org/api/process.html#process_event_unhandledrejection). To take advantage of auto-pipelining and handle your Promises, use `Promise.all()`.
```typescript
await Promise.all([
client.set('Tm9kZSBSZWRpcw==', 'users:1'),
client.sAdd('users:1:tokens', 'Tm9kZSBSZWRpcw==')
]);
```
### Clustering
Check out the [Clustering Guide](./docs/clustering.md) when using Node Redis to connect to a Redis Cluster.
### Events
The Node Redis client class is an Nodejs EventEmitter and it emits an event each time the network status changes:
| Name | When | Listener arguments |
|-------------------------|------------------------------------------------------------------------------------|------------------------------------------------------------|
| `connect` | Initiating a connection to the server | *No arguments* |
| `ready` | Client is ready to use | *No arguments* |
| `end` | Connection has been closed (via `.quit()` or `.disconnect()`) | *No arguments* |
| `error` | An error has occurred—usually a network issue such as "Socket closed unexpectedly" | `(error: Error)` |
| `reconnecting` | Client is trying to reconnect to the server | *No arguments* |
| `sharded-channel-moved` | See [here](./docs/pub-sub.md#sharded-channel-moved-event) | See [here](./docs/pub-sub.md#sharded-channel-moved-event) |
> :warning: You **MUST** listen to `error` events. If a client doesn't have at least one `error` listener registered and an `error` occurs, that error will be thrown and the Node.js process will exit. See the [`EventEmitter` docs](https://nodejs.org/api/events.html#events_error_events) for more details.
> The client will not emit [any other events](./docs/v3-to-v4.md#all-the-removed-events) beyond those listed above.
## Supported Redis versions
Node Redis is supported with the following versions of Redis:
| Version | Supported |
|---------|--------------------|
| 7.0.z | :heavy_check_mark: |
| 6.2.z | :heavy_check_mark: |
| 6.0.z | :heavy_check_mark: |
| 5.0.z | :heavy_check_mark: |
| < 5.0 | :x: |
> Node Redis should work with older versions of Redis, but it is not fully tested and we cannot offer support.
## Contributing
If you'd like to contribute, check out the [contributing guide](CONTRIBUTING.md).
Thank you to all the people who already contributed to Node Redis!
[](https://github.com/redis/node-redis/graphs/contributors)
## License
This repository is licensed under the "MIT" license. See [LICENSE](LICENSE).
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