diagnostics_channel

diagnostics_channel-polyfill

Exposes a polyfill for the Node.js module diagnostics_channel.

As of now, the Node.js module diagnostics_channel is only available in Node ^14.17.0 || >=15.1.0. This aim to allow using the same API on older versions of Node.

Install

npm i diagnostics_channel

Usage

Refer to the official documentation: https://nodejs.org/api/diagnostics_channel.html

Notes

• This module and the one included in Node core do NOT share the same channels, they live independently.
• Since WeakReference is not available, channels will NOT be garbage collected when no reference is held in user-land. An additional function is provided to do manual cleanup if needed: dc.deleteChannel(). This should not be needed in a typical scenario. Only use this method if you know why you are doing it.

const dc = require('diagnostics_channel');

const a = dc.channel('test');
const b = dc.channel('test');

// channel is memoized
console.log(a === b); // true

dc.deleteChannel('test');

const c = dc.channel('test');

// memoized channel was deleted and a new instance was memoized
console.log(a === c); // false

• Since ERR_INVALID_ARG_TYPE is not available, a simplfied copy of this error is included.
• Since triggerUncaughtException() is not available, if an exception is thrown in a subscriber, the polyfill will instead simply re-throw the error inside a process.nextTick(), which has a similar behavior except when the process crashes because of that exception: the crash message will point to this polyfill instead of where the error was created (ie: in the subscriber).

Similar packages

Other packages similar to diagnostics_channel

eventemitter3

EventEmitter3 is a high-performance event emitter. It offers similar publish/subscribe functionality but is not specifically designed for diagnostics or monitoring purposes. It is more general-purpose.

debug

The debug package allows you to create debug instances that can be turned on and off based on environment variables. It is similar in that it is used for diagnostics, but it does not provide a channel-based publish/subscribe mechanism.

bunyan

Bunyan is a JSON logging library for Node.js services. It provides detailed logs and includes mechanisms for streams and serializers. While it is used for diagnostics, it is more focused on logging than the publish/subscribe pattern.

winston

Winston is another logging library for Node.js. Similar to Bunyan, it is used for diagnostics and monitoring but is focused on logging with multiple transports, rather than a channel-based communication system.