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Chapter IV: Distributed System Concerns

Stateful vs Stateless

Keeping session state on the server vs. externalizing it for easy scaling.

In short

Stateful servers remember client session data; stateless servers keep none, making them easy to scale.

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Key takeaways

  • Stateless servers are interchangeable, so they scale and fail over easily.
  • Externalize state to Redis/a DB or carry it in client tokens (JWT).
  • Stateless avoids sticky sessions; state still lives somewhere shared.