Why architecture matters here

Rendezvous fails on wrong hash choice + weighted math bugs. Architecture matters because simplicity is the value.

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The architecture: every piece explained

The top strip is the algorithm. Key K + nodes. Hash(K, N_i). Argmax. Replication top-K nodes.

The middle row is properties. Add / remove node minimal remap. Memory O(1). Skeleton variant. Weighted.

The lower rows are practice. vs consistent hashing. Use cases. Ops — hash + weighting.

Rendezvous hashing — highest random weight + minimal remap + vs consistentno ring, just pick the maxKey K + nodescandidate setHash(K, N_i)per nodeArgmaxhighest weight winsReplicationtop-K nodesAdd / remove nodeminimal keys moveMemory O(1)no ring stateSkeleton variantlog-time selectionWeightedcapacity awarevs consistent hashingsimpler / more computeUse casescache LB + shard selectOps — hash choice + weighting + testsreshufflecheapscalecapacitycompareapplyapplyoperateoperate
Rendezvous hashing: hash(key, node), argmax, top-K.
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End-to-end flow

End-to-end: cache LB uses rendezvous. Each request keyed by user_id; hash(user_id, node_i) computed for all N nodes; top-2 selected for primary + backup. Adding a node moves 1/N of keys.