Distributed Task Scheduler

A robust distributed task scheduling system built with Go, gRPC, and PostgreSQL, designed to efficiently manage and execute distributed tasks across multiple workers.

Architecture

flowchart TB
    subgraph Client["Client Applications"]
        C1[Client 1]
        C2[Client 2]
        C3[Client N]
    end

    subgraph Core["Core Components"]
        S[Scheduler]
        CO[Coordinator]
        DB[(PostgreSQL DB)]
    end

    subgraph Workers["Worker Pool"]
        W1[Worker 1]
        W2[Worker 2]
        W3[Worker N]
    end

    subgraph Tasks["Worker Tasks"]
        T1[HTTP Server 1]
        T2[HTTP Server 2]
        T3[HTTP Server N]
    end

    C1 & C2 & C3 --> S
    S --> DB
    CO --> DB
    CO <--> W1 & W2 & W3
    W1 --> T1
    W2 --> T2
    W3 --> T3

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System Components

Scheduler

• Handles task scheduling and management
• Stores task definitions and schedules in PostgreSQL
• Provides API for task submission and management

Coordinator

• Manages worker pool and task distribution
• Performs periodic database scans for pending tasks
• Implements Round-Robin task assignment algorithm
• Monitors worker health and status through regular heartbeat.
• Handles worker failover and task reassignment

Workers

• Execute assigned tasks independently
• Run HTTP servers for task-specific operations
• Implement health check endpoints
• Maintain persistent connection with coordinator
• Support automatic restart mechanisms

PostgreSQL Database

• Stores task definitions and schedules
• Maintains worker and task state
• Ensures data persistence and reliability
• Handles concurrent access efficiently

Features

• Distributed Task Execution: Efficiently distribute tasks across multiple workers
• Health Monitoring: Comprehensive health check system
  • Worker connectivity status
  • Task processing state
  • Database connection health
  • Server availability checks
• Automatic Recovery: Self-healing mechanisms for worker failures
• Scalable Architecture: Easy to scale by adding more workers
• Docker Support: Containerized deployment with Docker Compose
• gRPC Communication: High-performance inter-service communication

Getting Started

Prerequisites

• Go 1.19 or higher
• PostgreSQL 13 or higher
• Docker and Docker Compose
• Prisma CLI

Installation

1. Clone the repository:

git clone https://github.com/yourusername/distributed-task-scheduler.git
cd distributed-task-scheduler

3. Start the services:

docker-compose build
docker-compose up --scale worker=3

This will start 3 worker images.

Configuration

Key configuration options in .env:

DATABASE_URL="postgresql://postgres:admin@postgres:5432/postgres?schema=public"

COORDINATOR_ADDRESS="http://localhost:8081"