HLD-121·Coordination & IDs
Easy · 500 ptsMicroservice Health-Check & Service Discovery Registry
Design a Consul / Netflix Eureka-style service registry handling continuous pod heartbeats and high-QPS endpoint discovery lookups across thousands of microservices.
Max p99
≤ 32 ms
Availability
≥ 99.5%
Budget
≤ $2,500
Functional Requirements
- FR-1POST /registry/{service_name}/heartbeat — Renews pod lease TTL and health status.
- FR-2GET /registry/{service_name}/endpoints — Returns healthy pod IP:port list to sidecar proxies.
- FR-3DELETE /registry/{service_name}/heartbeat — Releases canceled or expired leases/holds atomically and immediately refreshes cached availability.
- FR-4Sidecar discovery reads must remain available when a primary registry shard crashes.
Workload Profile
Steady Mesh Traffic20,000 Lookup RPS / 4,500 Heartbeat Write RPS
Cluster Rollout Surge56,000 Lookup RPS / 12,000 Heartbeat RPS
Active Working Set6 GB live pod endpoint leases
Traffic DistributionHeavy read fan-out on core auth/gateway service_name
Consistency Model
AP-first bounded eventual discovery (< 3s stale endpoint window acceptable with client health retries).
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