@opentelemetry/instrumentation-redis

What is @opentelemetry/instrumentation-redis?

@opentelemetry/instrumentation-redis is an npm package that provides automatic tracing and monitoring for Redis operations using the OpenTelemetry framework. It helps developers gain insights into the performance and behavior of their Redis interactions by capturing and exporting telemetry data.

What are @opentelemetry/instrumentation-redis's main functionalities?

Automatic Tracing

This feature allows you to automatically trace Redis operations. By registering the RedisInstrumentation with the OpenTelemetry tracer provider, all Redis commands will be traced and telemetry data will be collected.

const { NodeTracerProvider } = require('@opentelemetry/node');
const { registerInstrumentations } = require('@opentelemetry/instrumentation');
const { RedisInstrumentation } = require('@opentelemetry/instrumentation-redis');

const provider = new NodeTracerProvider();
provider.register();

registerInstrumentations({
  instrumentations: [
    new RedisInstrumentation(),
  ],
  tracerProvider: provider,
});

Custom Span Attributes

This feature allows you to add custom attributes to the spans created for Redis operations. By using the responseHook option, you can capture additional information from the Redis response and add it to the span.

const { RedisInstrumentation } = require('@opentelemetry/instrumentation-redis');

const redisInstrumentation = new RedisInstrumentation({
  responseHook: (span, cmdName, cmdArgs, response) => {
    span.setAttribute('redis.response', response);
  },
});

Error Handling

This feature allows you to handle errors in Redis operations and record them in the span. By checking if the response is an instance of Error, you can set the span status to indicate an error occurred.

const { RedisInstrumentation } = require('@opentelemetry/instrumentation-redis');

const redisInstrumentation = new RedisInstrumentation({
  responseHook: (span, cmdName, cmdArgs, response) => {
    if (response instanceof Error) {
      span.setStatus({ code: 2, message: response.message });
    }
  },
});

Other packages similar to @opentelemetry/instrumentation-redis

redis

The 'redis' package is a popular Redis client for Node.js. While it provides the basic functionality to interact with Redis, it does not offer built-in tracing or telemetry capabilities like @opentelemetry/instrumentation-redis. Developers would need to manually instrument their code to collect telemetry data.

ioredis

The 'ioredis' package is another widely-used Redis client for Node.js, known for its support of advanced Redis features and high performance. Similar to the 'redis' package, it does not include automatic tracing or telemetry features. Developers would need to integrate it with OpenTelemetry manually to achieve similar functionality to @opentelemetry/instrumentation-redis.

README

OpenTelemetry redis Instrumentation for Node.js

This module provides automatic instrumentation for the redis module versions >=2.6.0 <4, which may be loaded using the @opentelemetry/sdk-trace-node package and is included in the @opentelemetry/auto-instrumentations-node bundle.

If total installation size is not constrained, it is recommended to use the @opentelemetry/auto-instrumentations-node bundle with @opentelemetry/sdk-node for the most seamless instrumentation experience.

Compatible with OpenTelemetry JS API and SDK 1.0+.

Installation

npm install --save @opentelemetry/instrumentation-redis

Supported Versions

• redis versions >=2.6.0 <4

For versions redis@^4.0.0, please use @opentelemetry/instrumentation-redis-4

Usage

OpenTelemetry Redis Instrumentation allows the user to automatically collect trace data and export them to the backend of choice, to give observability to distributed systems when working with redis.

To load a specific instrumentation (redis in this case), specify it in the registerInstrumentations' configuration

const { NodeTracerProvider } = require('@opentelemetry/sdk-trace-node');
const { RedisInstrumentation } = require('@opentelemetry/instrumentation-redis');
const { registerInstrumentations } = require('@opentelemetry/instrumentation');

const provider = new NodeTracerProvider();
provider.register();

registerInstrumentations({
  instrumentations: [
    new RedisInstrumentation(),
  ],
})

See examples/redis for a short example.

Redis Instrumentation Options

Redis instrumentation has a few options available to choose from. You can set the following:

Options	Type	Description
dbStatementSerializer	DbStatementSerializer (function)	Redis instrumentation will serialize the command to the db.statement attribute using the specified function.
responseHook	RedisResponseCustomAttributeFunction (function)	Function for adding custom attributes on db response. Receives params: span, moduleVersion, cmdName, cmdArgs
requireParentSpan	boolean	Require parent to create redis span, default when unset is false.

Custom db.statement Serializer

The instrumentation serializes the command into a Span attribute called db.statement. The standard serialization format attempts to be as informative as possible while avoiding the export of potentially sensitive data. The number of serialized arguments depends on the specific command, see the configuration list in @opentelemetry/redis-common.

It is also possible to define a custom serialization function. The function will receive the command name and arguments and must return a string.

Here is a simple example to serialize the command name and all command arguments. Notice that it might capture sensitive data and big payloads:

const { RedisInstrumentation } = require('@opentelemetry/instrumentation-redis');

const redisInstrumentation = new RedisInstrumentation({
  dbStatementSerializer: function (cmdName, cmdArgs) {
    return [cmdName, ...cmdArgs].join(" ");
  },
});

Semantic Conventions

This package uses @opentelemetry/semantic-conventions version 1.22+, which implements Semantic Convention Version 1.7.0

Attributes collected:

Attribute	Short Description
db.connection_string	URL to Redis server address, of the form redis://host:port
db.statement	Executed Redis statement
db.system	Database identifier; always redis
net.peer.name	Hostname or IP of the connected Redis server
net.peer.port	Port of the connected Redis server

Useful links

• For more information on OpenTelemetry, visit: https://opentelemetry.io/
• For more about OpenTelemetry JavaScript: https://github.com/open-telemetry/opentelemetry-js
• For help or feedback on this project, join us in GitHub Discussions

License

Apache 2.0 - See LICENSE for more information.