node-redis guide (JavaScript) on Docs

Connect to the server

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Basic connection

Connect to localhost on port 6379.

Connect to Azure Managed Redis

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The @redis/entraid package lets you authenticate your app to Azure Managed Redis (AMR) using Microsoft Entra ID. You can authenticate using a system-assigned or user-assigned managed identity, a service principal, an auth code flow, or a DefaultAzureCredential instance. The @redis/entraid code fetches and renews the authentication tokens for you automatically.

Install

Install node-redis and @redis/entraid with the following commands:

Index and query documents

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This example shows how to create a search index for JSON documents and run queries against the index. It then goes on to show the slight differences in the equivalent code for hash documents.

Note:

From v5.0.0 onwards, node-redis uses query dialect 2 by default. Redis query engine methods such as ft.search() will explicitly request this dialect, overriding the default set for the server. See Query dialects for more information.

Initialize

Make sure that you have Redis Open Source or another Redis server available. Also install the node-redis client library if you haven't already done so.

Index and query vectors

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Redis Query Engine lets you index vector fields in hash or JSON objects (see the Vectors reference page for more information).

Vector fields can store text embeddings, which are AI-generated vector representations of text content. The vector distance between two embeddings measures their semantic similarity. When you compare the similarity of a query embedding with stored embeddings, Redis can retrieve documents that closely match the query's meaning.

In the example below, we use the @xenova/transformers library to generate vector embeddings to store and index with Redis Query Engine. The code is first demonstrated for hash documents with a separate section to explain the differences with JSON documents.

Vector set embeddings

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A Redis vector set lets you store a set of unique keys, each with its own associated vector. You can then retrieve keys from the set according to the similarity between their stored vectors and a query vector that you specify.

You can use vector sets to store any type of numeric vector but they are particularly optimized to work with text embedding vectors (see Redis for AI to learn more about text embeddings). The example below shows how to use the @xenova/transformers library to generate vector embeddings and then store and retrieve them using a vector set with node-redis.

Pipelines and transactions

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Redis lets you send a sequence of commands to the server together in a batch. There are two types of batch that you can use:

Pipelines avoid network and processing overhead by sending several commands to the server together in a single communication. The server then sends back a single communication with all the responses. See the Pipelining page for more information.
Transactions guarantee that all the included commands will execute to completion without being interrupted by commands from other clients. See the Transactions page for more information.

Execute a pipeline

There are two ways to execute commands in a pipeline. Firstly, node-redis will automatically pipeline commands that execute within the same "tick" of the event loop. You can ensure that commands happen in the same tick very easily by including them in a Promise.all() call, as shown in the following example. The chained then(...) callback is optional and you can often omit it for commands that write data and only return a status result.

Probabilistic data types

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Redis supports several probabilistic data types that let you calculate values approximately rather than exactly. The types fall into two basic categories:

Set operations: These types let you calculate (approximately) the number of items in a set of distinct values, and whether or not a given value is a member of a set.
Statistics: These types give you an approximation of statistics such as the quantiles, ranks, and frequencies of numeric data points in a list.

To see why these approximate calculations would be useful, consider the task of counting the number of distinct IP addresses that access a website in one day.

Error handling

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node-redis uses promises for error handling. Most Redis JavaScript examples throughout the documentation mainly show the "happy path" and omit error handling for brevity. This page shows how to apply error handling techniques in node-redis for real world code. For an overview of some common general error types and strategies for handling them, see Error handling. See also Production usage for more information on connection management, timeouts, and other aspects of app reliability.

Production usage

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This guide offers recommendations to get the best reliability and performance in your production environment.

Checklist

Each item in the checklist below links to the section for a recommendation. Use the checklist icons to record your progress in implementing the recommendations.

Migrate from ioredis

Mon, 01 Jan 0001 00:00:00 +0000

Redis previously recommended the ioredis client library for development with Node.js, but this library is now deprecated in favor of node-redis. This guide outlines the main similarities and differences between the two libraries. You may find this information useful if you are an ioredis user and you want to start a new Node.js project or migrate an existing ioredis project to node-redis.

Comparison of `ioredis` and `node-redis`

The tables below summarize how ioredis and node-redis implement some key features of Redis. See the following sections for more information about each feature.

node-redis guide (JavaScript) on Docs

Connect to the server

Basic connection

Connect to Azure Managed Redis

Install

Index and query documents

Initialize

Index and query vectors

Vector set embeddings

Pipelines and transactions

Execute a pipeline

Probabilistic data types

Error handling

Production usage

Checklist

Migrate from ioredis

Comparison of ioredis and node-redis

Comparison of `ioredis` and `node-redis`