3 posts
Clients time out, tcpdump shows SYNs (sometimes even SYN-ACK), yet your app logs nothing. The culprit is often the Linux listen/accept queues overflowing under load or CPU starvation.
Small API responses work, large ones hang forever. The cause: ICMP 'Fragmentation Needed' messages filtered by firewalls, breaking Path MTU Discovery in overlay networks.
Service can't connect to database - 'cannot assign requested address'. The cause: ephemeral ports exhausted by thousands of sockets stuck in TIME_WAIT state.