Raft3D - Distributed 3D Printer Management System

This project implements a distributed 3D printer management system using the Raft consensus algorithm. Nodes communicate via HTTP APIs and maintain a consistent replicated state across the cluster.

Installation

Install project dependencies:

go mod download
go mod tidy

Running Nodes

Start a node:

go run . --node_id=<NODE_ID> --raft_addr=127.0.0.1:900X --data_dir=<DATA_DIR> --http_port=<HTTP_PORT>

Note: Use the --bootstrap flag to create a new cluster with the first node.

Example Commands

Start a new leader node:

go run . --bootstrap --node_id=node1 --raft_addr=127.0.0.1:9001 --data_dir=node1_data --http_port=8081

Start additional follower nodes:

go run . --node_id=node2 --raft_addr=127.0.0.1:9002 --data_dir=node2_data --http_port=8082

go run . --node_id=node3 --raft_addr=127.0.0.1:9003 --data_dir=node3_data --http_port=8083

Joining Nodes to the Cluster

Join a node to the existing cluster by making a POST request to the leader node:

# Join node2 to the cluster
curl -X POST "http://localhost:8081/join?node_id=node2&addr=127.0.0.1:9002"

# Join node3 to the cluster
curl -X POST "http://localhost:8081/join?node_id=node3&addr=127.0.0.1:9003"

Checking Node Status

Check if a node is a Leader or Follower:

# Check node1 status
curl "http://localhost:8081/raft/state"

# Check node2 status
curl "http://localhost:8082/raft/state"

# Check node3 status
curl "http://localhost:8083/raft/state"

A leader node will return "Leader".

Follower nodes will return "Follower".

REST API Endpoints

Important: Always send API requests to the Leader node.

Printers

Add a printer:

curl -X POST http://localhost:8081/api/v1/printers -H "Content-Type: application/json" -d '{"id":"printer1","company":"HP","model":"L12"}'

Get all printers:

curl -X GET http://localhost:8081/api/v1/printers

Filaments

Add a filament:

curl -X POST http://localhost:8081/api/v1/filaments -H "Content-Type: application/json" -d '{"id":"f1","type":"PVC","color":"Black","total_weight_in_grams":100,"remaining_weight_in_grams":100}'

Get all filaments:

curl -X GET http://localhost:8081/api/v1/filaments

Print Jobs

Create a new print job:

curl -X POST http://localhost:8081/api/v1/print_jobs -H "Content-Type: application/json" -d '{"job_id":"job1","printer_id":"printer1","filament_id":"f1","print_weight_in_grams":50,"status":"Queued","details":"mountain"}'

Get all print jobs:

curl -X GET http://localhost:8081/api/v1/print_jobs

Updating Print Job Status

Allowed state transitions:

• Queued → Running → Done
• Queued → Cancelled
• Queued → Running → Cancelled

Example - Update job1 status to Running:

curl -X PUT "http://localhost:8081/api/v1/print_jobs/job1/status?status=Running"

Restarting a Node

To restart a previously stopped node:

go run . --node_id=node1 --raft_addr=127.0.0.1:9001 --data_dir=node1_data --http_port=8081

If the cluster is already running, the restarted node will rejoin as a Follower automatically.