Multi Step Processes easy
A 5-step wizard saves the user's progress in the web server's local RAM. If the load balancer sends the user's next request to a different server, what happens?
- A The servers automatically sync their RAM.
- B The user loses their progress because the new server doesn't have the data.
- C The database restores the RAM.
- D The request is rejected.
Answer: B. The user loses their progress because the new server doesn't have the data.
This is why web applications should be 'Stateless' (or store state in an external DB/Cache like Redis). Storing state in local RAM couples the user to a specific server, which breaks when scaling or load balancing.
One system design question a day, with spaced repetition so the ones you miss come back.
Get the appRelated questions
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