Socket.IO Postgres adapter

The @socket.io/postgres-adapter package allows broadcasting packets between multiple Socket.IO servers.

Table of contents

• Supported features
• Installation
• Usage
  • Standalone
  • With Node.js cluster
• Options
• License

Supported features

Feature	socket.io version	Support
Socket management	4.0.0	✅ YES (since version 0.1.0)
Inter-server communication	4.1.0	✅ YES (since version 0.1.0)
Broadcast with acknowledgements	4.5.0	✅ YES (since version 0.3.0)
Connection state recovery	4.6.0	❌ NO

Installation

npm install @socket.io/postgres-adapter

Usage

Standalone

import{Server}from"socket.io";import{createAdapter}from"@socket.io/postgres-adapter";importpgfrom"pg";constio=newServer();constpool=newpg.Pool({user: "postgres",host: "localhost",database: "postgres",password: "changeit",port: 5432,});pool.query(` CREATE TABLE IF NOT EXISTS socket_io_attachments ( id bigserial UNIQUE, created_at timestamptz DEFAULT NOW(), payload bytea );`);pool.on("error",(err)=>{console.error("Postgres error",err);});io.adapter(createAdapter(pool));io.listen(3000);

With Node.js cluster

importclusterfrom"node:cluster";import{createServer}from"node:http";import{availableParallelism}from"node:os";import{Server}from"socket.io";import{setupPrimary}from"@socket.io/postgres-adapter"import{createAdapter}from"@socket.io/cluster-adapter";importpgfrom"pg";if(cluster.isPrimary){constpool=newpg.Pool({user: "postgres",password: "changeit",});awaitpool.query(` CREATE TABLE IF NOT EXISTS socket_io_attachments ( id bigserial UNIQUE, created_at timestamptz DEFAULT NOW(), payload bytea ); `);setupPrimary(pool);for(leti=0;i<availableParallelism();i++){cluster.fork();}}else{constio=newServer({adapter: createAdapter(),});io.on("connection",(socket)=>{/* ... */});io.listen(3000);}

Options

Name	Description	Default value
channelPrefix	The prefix of the notification channel.	socket.io
tableName	The name of the table for payloads over the 8000 bytes limit or containing binary data.	socket_io_attachments
payloadThreshold	The threshold for the payload size in bytes (see https://www.postgresql.org/docs/current/sql-notify.html).	8_000
cleanupInterval	Number of ms between two cleanup queries.	30_000
heartbeatInterval	The number of ms between two heartbeats.	5_000
heartbeatTimeout	The number of ms without heartbeat before we consider a node down.	10_000

License

MIT