Questions
1 of 4
1Explain the replication handshake and partial resync (PSYNC2).
2How does Redis Sentinel work, and what are its failure scenarios?
3In Redis Cluster, explain how keys are distributed and what happens during a resharding.
4What is the CAP tradeoff in Redis Cluster, and how does it handle network partitions?
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01 / 04

Explain the replication handshake and partial resync (PSYNC2).

On connect, replica sends PSYNC <replid> <offset>. If the master's backlog contains that offset, it sends only the delta (partial resync). Otherwise, it triggers a full resync (BGSAVE + stream). Redis 4's PSYNC2 allows partial resync after failover using secondary replication IDs.