25B-toy-cdn-wid-failover

README

Go CDN Load Balancer with Monitoring

• Simulates a basic Content Delivery Network (CDN) with load balancing, caching, and monitoring, using Go.
• Includes origin servers and cache servers, with routing requests managed by a central router.
• Monitoring function runs in a separate goroutine, periodically reporting server loads and request distribution.

Excercise

Mimick CDN Failover

1. Configure multiple properties on same CDN under different CDN hostnames
2. Configure same website as origin for it.
3. For a given request, confire that 80% go to origin 1 while 20% goes to origin 2
4. Do this by creating CDN urls in the backend response

                         +-----------+           +------------------+
              |-> Router | CDN HostA |-----> 80% |  Origin Server 1 |
              |          +-----------+           +------------------+
              |             |
              |             |                     +------------------+
              |             |--------------> 20%  |  Origin Server 2 |
              |                                   +------------------+
User Request --
              |         +-----------+           +------------------+
              -> Router | CDN HostB |----> 80%  |  Origin Server 1 |
                        +-----------+           +------------------+
                           |
                           |                     +------------------+
                           |--------------> 20%  |  Origin Server 2 |
                                                 +------------------+

Project Structure

• Router: Routes incoming requests to cache servers in a round-robin manner.
• Cache Servers: Serve cached content if available; otherwise, fetch from origin servers.
• Origin Servers: Store original content and serve it to cache servers on cache misses.
• Monitoring: Tracks the number of requests handled by each server.

Usage

• Run the project with: go run main.go
• Create a folder named ./static with all images and videos.
• Endpoints:
  • The router listens on port :8000 and forwards requests to cache servers.
  • Cache servers listen on ports :8081 and :8082.
  • Origin servers listen on ports :8083 and :8084.

Output

Final Report

----- Monitoring Report -----
Cache Server :8081 - Requests served: 16
Cache Server :8082 - Requests served: 17
Origin Server :8083 - Load: 11
Origin Server :8084 - Load: 2
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