A CONNACK alone reset the backoff ladder, so a flapping broker (accepts
then drops within seconds) retried at the 10 s rung forever - each
attempt a full ~40 KB TLS session alloc/free on internal heap, a known
fragmentation driver. The ladder now clears only after the connection
survives 2 minutes (at least one 75 s keepalive round-trip); flapping
endpoints degrade to the 300 s rung and then the existing 30-minute
circuit-breaker probes, and recover automatically once stable.
agessaman
c119ad2ab9