Distributed Systems & System Design
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10 questions
Clear filtersReplication, Consistency & Consensus · Principal
The region failed over. Which promises survived?Local transaction atomicity does not imply regional survival. Acknowledgment, promotion authority, and consequential publication must protect the same business decision.
Replication, Consistency & Consensus · Staff
The follower has the commit record. Why is the read still old?Distinguish WAL receive, durable flush and replay visibility, and gate reads on a reliable apply boundary.
Replication, Consistency & Consensus · Senior
The profile saved. Why does your laptop still show the old name?Define scope of read-your-writes and design client or account-level consistency tokens with fallback behavior.
Replication, Consistency & Consensus · Staff
Two of three replicas agreed. Why did a later read return older data?Distinguish quorum intersection from monotonic reads and linearizability under partially applied or concurrent writes.
Replication, Consistency & Consensus · Staff
We added twenty read replicas. Why did the primary get slower?Diagnose write-history fanout, WAL-retention pressure, standby feedback and alternative read architectures.
Replication, Consistency & Consensus · Staff
The old leader is alive. Why won't the cluster accept its writes?Explain minority behavior, term-based elections, candidate freshness and the scope of reads under a network partition.
Replication, Consistency & Consensus · Staff
Three servers have the log entry. Why won't Raft commit it?Distinguish log replication from commitment of prior-term entries, and connect Raft terms, election restriction and current-term commitment.
Replication, Consistency & Consensus · Staff
The lease expired. Why can its previous owner still write?Distinguish lease expiration from the physical ability to write, and enforce non-regression with destination-side fencing.
Replication, Consistency & Consensus · Staff
The leader has applied every entry. Why might its read still be stale?Establish linearizable read authority using a quorum-confirmed read barrier and state-machine application, separate from local replay lag.
Replication, Consistency & Consensus · Principal
We added two voters. How could a routine change split the cluster?Prove overlapping authority across reconfiguration and plan learner promotion, joint consensus or sequential membership operations with failure recovery.