Networking & Firewall (Ss/Netstat/Iptables/Curl)

Stop ignoring the queue when your web server drops traffic

🧩 The Challenge

Dealing with a service that randomly drops connections during spikes is a special kind of hell. You’ll check the app logs and see nothing, but your monitoring is screaming about timeouts.

💡 The Fix

Check your socket listen queues to see if the kernel is actually backing up because your app can’t keep up with the incoming rate. If that Send-Q is hitting the Limit, your application isn’t accepting connections fast enough.

ss -tln | grep :80

⚙️ Why It Works

That Recv-Q column shows the number of connections waiting to be accepted by the application, while the Send-Q shows the max backlog limit configured for that socket. When they match, you’re officially dropping packets at the kernel level before the app even sees them.

🚀 Pro-Tip: Increase net.core.somaxconn in sysctl if you find your queue is consistently maxed out under load.

Linux Tips & Tricks | © ngelinux.com | 11/7/2026