Revision Notes/System Design Concepts
Field Entry - System Design Concepts
Content Delivery Network (CDN)
A globally distributed network of servers that caches and delivers static content to users from the nearest geographic location.
Field Note - Real-world Analogy
“Like a franchise fast food chain. The "main kitchen" (origin server) is in one city. But instead of every customer driving to that one kitchen, there are hundreds of local restaurants (edge nodes) in every city. Local customers get their food from the local branch — fast. The main kitchen only handles new recipes (dynamic content) and keeps the branches supplied.”
Field Observations - Key Topics Covered
Without a CDN, all users — whether they're in Mumbai or New York — send requests to your single origin server. A user in Mumbai requesting content from a New York server experiences high latency because the data travels across the planet (typically 100-200ms just for the network round trip).
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