mubsub-nbb

library1.6.1jsnpmunverified

Mubsub is a pub/sub implementation for Node.js using MongoDB capped collections and tailable cursors. This fork (mubsub-nbb, published as @nodebb/mubsub) updates the original package for compatibility with mongodb 3.x driver. Version 1.6.1 is the latest stable release, maintained sporadically by NodeBB. It allows publishing events as documents into capped collections and supports event filtering via MongoDB queries. Key differentiators: leverages MongoDB's native tailable cursors for real-time notifications, supports flexible channel configuration (size, max, retry interval), and does not require additional infrastructure beyond MongoDB.

database

npm install mubsub-nbb

github ↗package ↗homepage ↗

INSTALL

IMPORT

SIG · MUBSUB-NBB

mubsub-nbb

databasejavascriptv1.6.1

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

mubsub

✓ import mubsub from '@nodebb/mubsub';

✗ const mubsub = require('mubsub');

Use the scoped @nodebb/mubsub package. The old mubsub package is deprecated.

Client

✓ const client = mubsub(uri, options); // returns a Client instance

✗ const client = new mubsub(uri);

mubsub is a factory function, not a constructor.

Channel

✓ const channel = client.channel(name, options); // returns a Channel instance

✗ const channel = mubsub.channel(name);

Call channel() on a client instance, not on the mubsub function.

Demonstrates creating a client, subscribing to events, publishing messages, and closing the connection.

import mubsub from '@nodebb/mubsub'; const client = mubsub('mongodb://localhost:27017/mubsub_example'); client.on('error', (err) => console.error('Client error:', err)); const channel = client.channel('test'); channel.on('error', (err) => console.error('Channel error:', err)); channel.subscribe('bar', (message) => { console.log(message.foo); // 'bar' }); channel.subscribe('baz', (message) => { console.log(message); // 'baz' }); setTimeout(() => { channel.publish('bar', { foo: 'bar' }); channel.publish('baz', 'baz'); }, 1000); setTimeout(() => { client.close(); }, 3000);

Debug

Known issues

breakingThe package name changed from 'mubsub' to '@nodebb/mubsub'. Install the scoped package.

fix

npm install @nodebb/mubsub

affects: >=1.0

deprecatedThe 'mubsub' package (original) is unmaintained. Use '@nodebb/mubsub' for mongodb 3.x compatibility.

fix

Switch to '@nodebb/mubsub'.

affects: <1.0

gotchaDo not remove capped collections while publishers are active; mongod may recreate it as an uncapped collection, breaking subscriptions.

fix

Ensure channels are only deleted when no publishers are active.

affects: *

gotchaCreating many channels (capped collections) is expensive; each channel maintains a tailable cursor polling loop.

fix

Limit the number of channels to avoid performance degradation.

affects: *

Errors

Common errors & fixes

TypeError: mubsub is not a function

Using the old 'mubsub' package (unscoped) or importing incorrectly.

fix

Run: npm install @nodebb/mubsub and import using: import mubsub from '@nodebb/mubsub';

MongoError: can't find collection

The capped collection for the channel was dropped or never created.

fix

Ensure the MongoDB connection URI points to a database that exists and has write permissions.

Error: Client is not connected to MongoDB

Calling channel() or publish() before the client connection is established.

fix

Wait for the client 'connect' event or ensure MongoDB is reachable.

Upgrade

Version history

1.6.1latest on npm

Audit

Dependencies

mongodbrequiredrequires mongodb driver (3.x compatible)

Agent activity

2 hits · last 30 days

node

Resources

githubgit://github.com/NodeBB/mubsub ↗

packagemubsub-nbb ↗

homepagehttps://github.com/NodeBB/mubsub ↗