HLD-406·Storage & Caching
Expert · 2,000 ptsPartitioned Quorum Key-Value Store (Dynamo / Cassandra)
Design a planet-scale consistent-hashed Key-Value storage engine supporting `R + W > N` quorum consistency, hot-partition splitting/salting, and sub-second node crash recovery.
Max p99
≤ 75 ms
Availability
≥ 99.5%
Budget
≤ $11,600
Functional Requirements
- FR-1PUT /kv/{partition_key} — Commits versioned mutation across `W` quorum replicas with WAL durability.
- FR-2GET /kv/{partition_key} — Executes `R` quorum read/cache lookup returning latest committed version.
- FR-3DELETE /kv/{partition_key} — Releases canceled or expired leases/holds atomically and immediately refreshes cached availability.
- FR-4Must guarantee linearizable/quorum read-after-write and zero data loss across storage node crashes at 240k RPS.
Workload Profile
Baseline Cluster Load82,000 Read RPS / 14,000 Quorum Write RPS
Hot-Partition Storm210,000 Read RPS / 34,000 Quorum Write RPS
Active Working Set56 GB hot LSM memtables & block/row caches
Consistency GateStrict R+W>N quorum consistency + RPO = 0 failover
Consistency Model
Strict quorum (`R + W > N`) + atomic version CAS so concurrent writers never clobber or serve stale values.
Solutions Locked
Sign in and either achieve AC or complete 3 official submissions on this question to inspect community diagrams and writeups.
Loading solutions...
Submission History (0)Select to replay
No submissions yet
Click Submit in the top bar to evaluate against all 7 judge cases and save each run here.
Design Write-up
0 boxes · 0 edges
0 words