Instrumenting Redis for Structural Leak Detection: A jemalloc Deep Dive

Instrumented Redis 7.2 with drainability profiling to measure jemalloc slab fragmentation. Found critical asymmetric accounting bug, fixed with symmetric fastpath instrumentation. Final result: deleting 50% of keys freed 195K objects but achieved 0% drainability - genuine structural fragmentation detected and validated.

February 20, 2026 · map[name:Blackwell Systems]