Interview Questions/Troubleshooting Scenarios/Thread Pool Exhaustion Causing Latency
IntermediateScenario
10 min

Thread Pool Exhaustion Causing Latency

PerformanceConcurrencyAPIs
Advertisement
Interview Question

Sudden latency spikes correlate with saturated server thread pools. How do you diagnose and remediate safely?

Key Points to Cover
  • Instrument busy/queued threads, queue length, and wait times
  • Identify blocking operations and synchronous I/O
  • Right-size pools; introduce async/IO multiplexing where safe
  • Apply backpressure/timeouts to avoid unbounded queues
  • Load test and validate new pool sizes under peak patterns
Evaluation Rubric
Uses the right thread/queue metrics30% weight
Finds blocking operations30% weight
Balances pool sizing and backpressure20% weight
Verifies with representative load20% weight
Hints
  • 💡Beware of deadlocks after pool changes.
Potential Follow-up Questions
  • How to avoid priority inversion?
  • What about CPU vs IO-bound pools?
Advertisement