@keyv/redis

What is @keyv/redis?

@keyv/redis is an npm package that provides a Redis storage adapter for Keyv, a simple key-value storage library. It allows you to use Redis as a backend for storing key-value pairs, making it easy to integrate Redis into your Node.js applications.

What are @keyv/redis's main functionalities?

Basic Key-Value Storage

This feature allows you to store and retrieve basic key-value pairs using Redis as the backend. The code sample demonstrates how to set and get a value from the Redis store.

const Keyv = require('keyv');
const keyv = new Keyv('redis://user:pass@localhost:6379');

(async () => {
  await keyv.set('foo', 'bar');
  const value = await keyv.get('foo');
  console.log(value); // 'bar'
})();

Expiration of Keys

This feature allows you to set an expiration time for keys. The code sample demonstrates how to set a key with an expiration time and shows that the key is no longer available after the specified time.

const Keyv = require('keyv');
const keyv = new Keyv('redis://user:pass@localhost:6379');

(async () => {
  await keyv.set('foo', 'bar', 1000); // Expires in 1 second
  setTimeout(async () => {
    const value = await keyv.get('foo');
    console.log(value); // undefined
  }, 1500);
})();

Namespace Support

This feature allows you to use namespaces to avoid key collisions. The code sample demonstrates how to set and get a value within a specific namespace.

const Keyv = require('keyv');
const keyv = new Keyv({ uri: 'redis://user:pass@localhost:6379', namespace: 'myapp' });

(async () => {
  await keyv.set('foo', 'bar');
  const value = await keyv.get('foo');
  console.log(value); // 'bar'
})();

Other packages similar to @keyv/redis

ioredis

ioredis is a robust, full-featured Redis client for Node.js. It supports advanced Redis features like clustering, sentinel, and pipelining. Compared to @keyv/redis, ioredis offers more direct control over Redis commands and is suitable for more complex use cases.

redis

redis is the official Node.js client for Redis. It provides a straightforward API for interacting with Redis and supports all Redis commands. While @keyv/redis focuses on key-value storage with a simple API, redis offers more granular control and flexibility.

node-cache

node-cache is an in-memory caching module for Node.js. It provides a simple API for storing key-value pairs with optional expiration times. Unlike @keyv/redis, node-cache does not use Redis as a backend and is suitable for use cases where in-memory storage is sufficient.

README

@keyv/redis

Redis storage adapter for Keyv

Redis storage adapter for Keyv.

Features

• Built on top of redis.
• TTL is handled directly by Redis.
• Supports Redis Clusters.
• Url connection string support or pass in your Redis Options
• Easily add in your own Redis client.
• Namespace support for key management.
• Unlink as default delete method for performance.
• Access to the Redis client for advanced use cases.
• Keyv and Redis Libraries are exported for advanced use cases.
• createKeyv function for easy creation of Keyv instances.
• jsDoc comments for easy documentation.
• CJS / ESM and TypeScript supported out of the box.

Table of Contents

• Usage
• Namespaces
• Performance Considerations
• High Memory Usage on Redis Server
• Using Cacheable with Redis
• Clustering and TLS Support
• API
• Migrating from v3 to v4
• About Redis Sets and its Support in v4
• License

Usage

Here is a standard use case where we implement Keyv and @keyv/redis:

import Keyv from 'keyv';
import KeyvRedis from '@keyv/redis';

const keyv = new Keyv(new KeyvRedis('redis://user:pass@localhost:6379'));
keyv.on('error', handleConnectionError);

Here is the same example but with the Keyv instance created with the createKeyv function:

import { createKeyv } from '@keyv/redis';

const keyv = createKeyv('redis://user:pass@localhost:6379', { namespace: 'my-namespace' });

You only have to import the @keyv/redis library if you are using the createKeyv function. 🎉 Otherwise, you can import Keyv and @keyv/redis independently.

Here you can pass in the Redis options directly:

import Keyv from 'keyv';
import KeyvRedis from '@keyv/redis';

const redisOptions = {
  url: 'redis://localhost:6379', // The Redis server URL (use 'rediss' for TLS)
  password: 'your_password', // Optional password if Redis has authentication enabled

  socket: {
    host: 'localhost', // Hostname of the Redis server
    port: 6379,        // Port number
    reconnectStrategy: (retries) => Math.min(retries * 50, 2000), // Custom reconnect logic

    tls: false, // Enable TLS if you need to connect over SSL
    keepAlive: 30000, // Keep-alive timeout (in milliseconds)
  }
};

const keyv = new Keyv(new KeyvRedis(redisOptions));

Or you can create a new Redis instance and pass it in with KeyvOptions:

import Keyv from 'keyv';
import KeyvRedis, { createClient } from '@keyv/redis';

const redis = createClient('redis://user:pass@localhost:6379', { namespace: 'my-namespace'});
const keyvRedis = new KeyvRedis(redis);
const keyv = new Keyv({ store: keyvRedis });

Namespaces

You can set a namespace for your keys. This is useful if you want to manage your keys in a more organized way. Here is an example of how to set a namespace:

import Keyv from 'keyv';
import KeyvRedis from '@keyv/redis';

const keyv = new Keyv(new KeyvRedis('redis://user:pass@localhost:6379', { namespace: 'my-namespace' }));

This will prefix all keys with my-namespace:. You can also set the namespace after the fact:

keyv.namespace = 'my-namespace';

NOTE: If you plan to do many clears or deletes, it is recommended to read the Performance Considerations section.

Performance Considerations

With namespaces being prefix based it is critical to understand some of the performance considerations we have made:

• clear() - We use the SCAN command to iterate over keys. This is a non-blocking command that is more efficient than KEYS. In addition we are using UNLINK by default instead of DEL. Even with that if you are iterating over a large dataset it can still be slow. It is highly recommended to use the namespace option to limit the keys that are being cleared and if possible to not use the clear() method in high performance environments.

• delete() - By default we are now using UNLINK instead of DEL for deleting keys. This is a non-blocking command that is more efficient than DEL. If you are deleting a large number of keys it is recommended to use the deleteMany() method instead of delete().

• clearBatchSize - The clearBatchSize option is set to 1000 by default. This is because Redis has a limit of 1000 keys that can be deleted in a single batch.

• useUnlink - This option is set to true by default. This is because UNLINK is a non-blocking command that is more efficient than DEL. If you are not using UNLINK and are doing a lot of deletes it is recommended to set this option to true.

• setMany, getMany, deleteMany - These methods are more efficient than their singular counterparts. These will be used by default in the Keyv library such as when using keyv.delete(string[]) it will use deleteMany().

If you want to see even better performance please see the Using Cacheable with Redis section as it has non-blocking and in-memory primary caching that goes along well with this library and Keyv.

High Memory Usage on Redis Server

This is because we are using UNLINK by default instead of DEL. This is a non-blocking command that is more efficient than DEL but will slowly remove the memory allocation.

If you are deleting or clearing a large number of keys you can disable this by setting the useUnlink option to false. This will use DEL instead of UNLINK and should reduce the memory usage.

const keyv = new Keyv(new KeyvRedis('redis://user:pass@localhost:6379', { useUnlink: false }));
// Or
keyv.useUnlink = false;

Using Cacheable with Redis

If you are wanting to see even better performance with Redis, you can use Cacheable which is a multi-layered cache library that has in-memory primary caching and non-blocking secondary caching. Here is an example of how to use it with Redis:

import KeyvRedis from '@keyv/redis';
import Cacheable from 'cacheable';

const secondary = new KeyvRedis('redis://user:pass@localhost:6379');

const cache = new Cacheable( { secondary } );

For even higher performance you can set the nonBlocking option to true:

const cache = new Cacheable( { secondary, nonBlocking: true } );

This will make it so that the secondary does not block the primary cache and will be very fast. 🚀

Clustering and TLS Support

If you are using a Redis Cluster or need to use TLS, you can pass in the redisOptions directly. Here is an example of how to do that:

import Keyv from 'keyv';
import KeyvRedis, { createCluster } from '@keyv/redis';

const cluster = createCluster({
    rootNodes: [
      {
        url: 'redis://127.0.0.1:7000',
      },
      {
        url: 'redis://127.0.0.1:7001',
      },
      {
        url: 'redis://127.0.0.1:7002',
      },
    ],
});

const keyv = new Keyv({ store: new KeyvRedis(cluster) });

There are some features that are not supported in clustering such as clear() and iterator(). This is because the SCAN command is not supported in clustering. If you need to clear or delete keys you can use the deleteMany() method.

You can learn more about the createCluster function in the documentation at https://github.com/redis/node-redis/tree/master/docs.

Here is an example of how to use TLS:

import Keyv from 'keyv';
import KeyvRedis from '@keyv/redis';

const tlsOptions = {
    socket: {
      host: 'localhost',
      port: 6379,
      tls: true,  // Enable TLS connection
      rejectUnauthorized: false,  // Ignore self-signed certificate errors (for testing)
      
      // Alternatively, provide CA, key, and cert for mutual authentication
      ca: fs.readFileSync('/path/to/ca-cert.pem'),
      cert: fs.readFileSync('/path/to/client-cert.pem'),  // Optional for client auth
      key: fs.readFileSync('/path/to/client-key.pem'),    // Optional for client auth
    }
};

const keyv = new Keyv({ store: new KeyvRedis(tlsOptions) });

API

• constructor([connection], [options])
• namespace - The namespace to use for the keys.
• client - The Redis client instance.
• keyPrefixSeparator - The separator to use between the namespace and key.
• clearBatchSize - The number of keys to delete in a single batch.
• useUnlink - Use the UNLINK command for deleting keys isntead of DEL.
• set - Set a key.
• setMany - Set multiple keys.
• get - Get a key.
• getMany - Get multiple keys.
• has - Check if a key exists.
• hasMany - Check if multiple keys exist.
• delete - Delete a key.
• deleteMany - Delete multiple keys.
• clear - Clear all keys. If the namespace is set it will only clear keys with that namespace.
• disconnect - Disconnect from the Redis server.
• iterator - Create a new iterator for the keys.

Migrating from v3 to v4

Overall the API is the same as v3 with additional options and performance improvements. Here are the main changes:

• The ioredis library has been removed in favor of the redis aka node-redis library. If you want to use ioredis you can use @keyv/keyval
• The useUnlink option has been added to use UNLINK instead of DEL and set to true by default.
• The clearBatchSize option has been added to set the number of keys to delete in a single batch.
• The clear() and delete() methods now use UNLINK instead of DEL. If you want to use DEL you can set the useUnlink option to false.
• BREAKING: We no longer support redis sets. This is due to the fact that it caused significant performance issues and was not a good fit for the library.
• BREAKING: YOUR PREVIOUS KEYS WILL NOT BE VALID. This is because of the fixe of the namespace support and how it is handled. Now, when using keyv with @keyv/redis as the storage adapter you can do the following:

import Keyv from 'keyv';
import KeyvRedis from '@keyv/redis';

const redis = new KeyvRedis('redis://user:pass@localhost:6379');
const keyv = new Keyv({ store: redis, namespace: 'my-namespace', useKeyPrefix: false });

This will make it so the storage adapter @keyv/redis will handle the namespace and not the keyv instance. If you leave it on it will just look duplicated like my-namespace:my-namespace:key.

About Redis Sets and its Support in v4

We no longer support redis sets. This is due to the fact that it caused significant performance issues and was not a good fit for the library.

License

MIT © Jared Wray