Symptoms: latency rises sharply with load while CPU stays low, timeouts appear, and health checks fail.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 | # ====================================================================== # Q: What is thread pool starvation? How do you detect and fix it? # # Symptoms: latency rises sharply with load while CPU stays low, timeouts # appear, and health checks fail. Cause: threads that block (.Result, # Thread.Sleep, sync I/O, a lock with long waits). Above the minimum, the pool # adds new threads slowly (about 1-2 per second), so the queue keeps growing. # Fix: async all the way. ThreadPool.SetMinThreads is a patch, not a solution. # If a library only has a sync API, isolate it (a separate worker, a limit on # concurrent calls). # ====================================================================== dotnet-counters monitor -n Shop.Api --counters System.Runtime # ThreadPool Queue Length rising, ThreadPool Thread Count rising slowly → starvation dotnet-stack report -p <pid> # where the threads are "stuck" |
