@keyv/redis

Redis storage adapter for Keyv

Redis storage adapter for Keyv.

Features

• Built on top of @redis/client.
• 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
• Using Generic Types
• Performance Considerations
• High Memory Usage on Redis Server
• Gracefully Handling Connection Errors, Retries, and Timeouts
• Using Cacheable with Redis
• Clustering and TLS Support
• API
• Using Custom Redis Client Events
• Migrating from v3 to v4
• About Redis Sets and its Support in v4
• License

Installation

1npm install --save keyv @keyv/redis

Usage

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

1import Keyv from 'keyv';
2import KeyvRedis from '@keyv/redis';
3
4const keyv = new Keyv(new KeyvRedis('redis://user:pass@localhost:6379'));
5keyv.on('error', handleConnectionError);

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

1import { createKeyv } from '@keyv/redis';
2
3const keyv = createKeyv('redis://user:pass@localhost:6379');

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:

1import Keyv from 'keyv';
2import KeyvRedis from '@keyv/redis';
3
4const redisOptions = {
5  url: 'redis://localhost:6379', // The Redis server URL (use 'rediss' for TLS)
6  password: 'your_password', // Optional password if Redis has authentication enabled
7
8  socket: {
9    host: 'localhost', // Hostname of the Redis server
10    port: 6379,        // Port number
11    reconnectStrategy: (retries) => Math.min(retries * 50, 2000), // Custom reconnect logic
12
13    tls: false, // Enable TLS if you need to connect over SSL
14    keepAlive: 30000, // Keep-alive timeout (in milliseconds)
15  }
16};
17
18const keyv = new Keyv(new KeyvRedis(redisOptions));

Or you can create a new Redis instance and pass it in with KeyvOptions such as setting the store:

1import Keyv from 'keyv';
2import KeyvRedis, { createClient } from '@keyv/redis';
3
4const redis = createClient('redis://user:pass@localhost:6379');
5const keyvRedis = new KeyvRedis(redis);
6const keyv = new Keyv({ store: keyvRedis});

Keyv Redis Options

You can pass in options to the KeyvRedis constructor. Here are the available options:

1export type KeyvRedisOptions = {
2	/**
3	 * Namespace for the current instance.
4	 */
5	namespace?: string;
6	/**
7	 * Separator to use between namespace and key.
8	 */
9	keyPrefixSeparator?: string;
10	/**
11	 * Number of keys to delete in a single batch.
12	 */
13	clearBatchSize?: number;
14	/**
15	 * Enable Unlink instead of using Del for clearing keys. This is more performant but may not be supported by all Redis versions.
16	 */
17	useUnlink?: boolean;
18
19	/**
20	 * Whether to allow clearing all keys when no namespace is set.
21	 * If set to true and no namespace is set, iterate() will return all keys.
22	 * Defaults to `false`.
23	 */
24	noNamespaceAffectsAll?: boolean;
25
26	/**
27	 * Timeout for connecting to Redis in milliseconds. This is used to prevent hanging indefinitely when connecting to Redis.
28	 * Defaults to `200`.
29	 */
30	connectTimeout?: number;
31};

You can pass these options when creating a new KeyvRedis instance:

1import Keyv from 'keyv';
2import KeyvRedis from '@keyv/redis';
3
4const keyvRedis = new KeyvRedis({
5  namespace: 'my-namespace',
6  keyPrefixSeparator: ':',
7  clearBatchSize: 1000,
8  useUnlink: true,
9  noNamespaceAffectsAll: false,
10  connectTimeout: 200
11});
12
13const keyv = new Keyv({ store: keyvRedis });

You can also set these options after the fact by using the KeyvRedis instance properties:

1import {createKeyv} from '@keyv/redis';
2
3const keyv = createKeyv('redis://user:pass@localhost:6379');
4keyv.store.namespace = 'my-namespace';

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 with the store option:

1import Keyv from 'keyv';
2import KeyvRedis, { createClient } from '@keyv/redis';
3
4const redis = createClient('redis://user:pass@localhost:6379');
5const keyvRedis = new KeyvRedis(redis);
6const keyv = new Keyv({ store: keyvRedis, namespace: 'my-namespace' });

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

1keyv.namespace = 'my-namespace';

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

Using Generic Types

When initializing KeyvRedis, you can specify the type of the values you are storing and you can also specify types when calling methods:

1import Keyv from 'keyv';
2import KeyvRedis, { createClient } from '@keyv/redis';
3
4
5type User {
6  id: number
7  name: string
8}
9
10const redis = createClient('redis://user:pass@localhost:6379');
11
12const keyvRedis = new KeyvRedis<User>(redis);
13const keyv = new Keyv({ store: keyvRedis });
14
15await keyv.set("user:1", { id: 1, name: "Alice" })
16const user = await keyv.get("user:1")
17console.log(user.name) // 'Alice'
18
19// specify types when calling methods
20const user = await keyv.get<User>("user:1")
21console.log(user.name) // 'Alice'

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. If you don't set namespaces, you can enable noNamespaceAffectsAll to clear all keys using the FLUSHDB command which is faster and can be used in production 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. If no namespace is defined and noNamespaceAffectsAll is set to true this option will be ignored and the FLUSHDB command will be used instead.

• 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.

1const keyv = new Keyv(new KeyvRedis('redis://user:pass@localhost:6379', { useUnlink: false }));
2// Or
3keyv.useUnlink = false;

Gracefully Handling Connection Errors, Retries, and Timeouts

When using @keyv/redis, it is important to handle connection errors gracefully. You can do this by listening to the error event on the KeyvRedis instance. Here is an example of how to do that:

1import Keyv from 'keyv';
2import KeyvRedis from '@keyv/redis';
3const keyv = new Keyv(new KeyvRedis('redis://user:pass@localhost:6379'));
4keyv.on('error', (error) => {
5  console.error('error', error);
6});

We also attempt to connect to Redis and have a connectTimeout option that defaults to 200ms. If the connection is not established within this time, it will emit an error. You can catch this error and handle it accordingly.

On get, getMany, set, setMany, delete, deleteMany, and clear methods, if the connection is lost, it will emit an error and return a no-op value. You can catch this error and handle it accordingly. This is important to ensure that your application does not crash due to a lost connection to Redis.

If you pass in just a uri connection string we will automatically create a Redis client for you with the following reconnect strategy:

1export const defaultReconnectStrategy = (attempts: number): number | Error => {
2	// Exponential backoff base: double each time, capped at 2s.
3	// Parentheses make it clear we do (2 ** attempts) first, then * 100
4	const backoff = Math.min((2 ** attempts) * 100, 2000);
5
6	// Add random jitter of up to ±50ms to avoid thundering herds:
7	const jitter = (Math.random() - 0.5) * 100;
8
9	return backoff + jitter;
10};

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:

1import KeyvRedis from '@keyv/redis';
2import Cacheable from 'cacheable';
3
4const secondary = new KeyvRedis('redis://user:pass@localhost:6379');
5
6const cache = new Cacheable( { secondary } );

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

1const 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:

1import Keyv from 'keyv';
2import KeyvRedis, { createCluster } from '@keyv/redis';
3
4const cluster = createCluster({
5    rootNodes: [
6      {
7        url: 'redis://127.0.0.1:7000',
8      },
9      {
10        url: 'redis://127.0.0.1:7001',
11      },
12      {
13        url: 'redis://127.0.0.1:7002',
14      },
15    ],
16});
17
18const keyv = new Keyv({ store: new KeyvRedis(cluster) });

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:

1import Keyv from 'keyv';
2import KeyvRedis from '@keyv/redis';
3
4const tlsOptions = {
5    socket: {
6      host: 'localhost',
7      port: 6379,
8      tls: true,  // Enable TLS connection
9      rejectUnauthorized: false,  // Ignore self-signed certificate errors (for testing)
10      
11      // Alternatively, provide CA, key, and cert for mutual authentication
12      ca: fs.readFileSync('/path/to/ca-cert.pem'),
13      cert: fs.readFileSync('/path/to/client-cert.pem'),  // Optional for client auth
14      key: fs.readFileSync('/path/to/client-key.pem'),    // Optional for client auth
15    }
16};
17
18const 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. It can be set to a blank string.
• clearBatchSize - The number of keys to delete in a single batch. Has to be greater than 0. Default is 1000.
• useUnlink - Use the UNLINK command for deleting keys isntead of DEL.
• noNamespaceAffectsAll: Whether to allow clearing all keys when no namespace is set (default is false).
• 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 in the namespace. If the namespace is not set it will clear all keys that are not prefixed with a namespace unless noNamespaceAffectsAll is set to true.
• disconnect - Disconnect from the Redis server using Quit command. If you set force to true it will force the disconnect.
• iterator - Create a new iterator for the keys. If the namespace is not set it will iterate over all keys that are not prefixed with a namespace unless noNamespaceAffectsAll is set to true.

Using Custom Redis Client Events

Keyv by default supports the error event across all storage adapters. If you want to listen to other events you can do so by accessing the client property of the KeyvRedis instance. Here is an example of how to do that:

1import {createKeyv} from '@keyv/redis';
2
3const keyv = createKeyv('redis://user:pass@localhost:6379');
4const redisClient = keyv.store.client;
5
6redisClient.on('connect', () => {
7  console.log('Redis client connected');
8});
9
10redisClient.on('reconnecting', () => {
11  console.log('Redis client reconnecting');
12});
13
14redisClient.on('end', () => {
15  console.log('Redis client disconnected');
16});

Here are some of the events you can listen to: https://www.npmjs.com/package/redis#events

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/valkey
• 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:

1import Keyv from 'keyv';
2import KeyvRedis from '@keyv/redis';
3
4const redis = new KeyvRedis('redis://user:pass@localhost:6379');
5const 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