Building a Scalable Go-Based Instant Messaging System: Architecture & Deployment Guide

This article introduces a simple Go‑based instant messaging (IM) system.

Overview

The IM system is implemented entirely in Go, with three independent layers that communicate via RPC, support clustering, and are available on GitHub at github.com/Terry-Ye/im_api . It draws inspiration from goim.

Comet (user connection layer) – multiple nodes can be deployed, each with a unique serverId defined in comet.toml.

Logic (business logic layer) – stateless, communicates with other layers via RPC, and offers an HTTP interface for receiving messages.

Job (task push layer) – uses Redis pub/sub to push messages to the Comet layer.

System Architecture Diagram

Sequence Diagram

The Comet, Logic, and Job layers can each be scaled horizontally.

Features

Distributed, topology‑aware architecture.

Supports both single‑user and room‑based push.

Heartbeat support (built into gorilla/websocket).

Message pushing based on Redis.

Lightweight.

Continuous iteration.

Deployment

Installation:

go get -u github.com/Terry-Ye/im
mv $GOPATH/src/github.com/Terry-Ye/im $GOPATH/src/im
cd $GOPATH/src/im
go get ./...

If golang.org/x/net/ipv4 cannot be fetched, clone it manually:

package golang.org/x/net/ipv4: unrecognized import path "golang.org/x/net/ipv4" (https fetch: Get https://golang.org/x/net/ipv4?go-get=1: dial tcp 216.239.37.1:443: i/o timeout)

Clone and move the repository:

git clone https://github.com/golang/net.git
mkdir -p golang.org/x/
mv net $GOPATH/src/golang.org/x/

Deploy the IM system:

cd $GOPATH/src/im/comet
go install
cd ../logic/
go install
cd ../job
go install

nohup $GOPATH/bin/logic -d $GOPATH/src/im/logic/ 2>&1 > /data/log/im/logic.log &
nohup $GOPATH/bin/comet -d $GOPATH/src/im/comet/ 2>&1 > /data/log/im/comet.log &
nohup $GOPATH/bin/job -d $GOPATH/src/im/job/ 2>&1 > /data/log/im/job.log &

The im_api interface requires the full deployment to run the demo.

Deployment Considerations

Ensure firewall ports required by each layer are open on the server.

Demo

Chatroom URL: http://www.texixi.com:1999/

Used Packages

log: github.com/sirupsen/logrus rpc: github.com/smallnest/rpcx websocket: github.com/gorilla/websocket configuration:

github.com/spf13/viper

Future Plans

Online user list.

Support for WSS (secure WebSocket).

Chatbot integration.

Original source: www.ancii.com/awugjp68e/