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When benchmarking comet applications or high-traffic servers, traditional tools like netstat become inefficient at scale. The command:

netstat -ant | grep 8080 | grep EST | wc -l

can take 4-6 minutes to process 100,000-250,000 connections due to:

• Full socket table traversal
• Text parsing overhead
• Multiple process forks (grep/wc)

1. ss (Socket Statistics)

The modern replacement for netstat, using kernel-level counters:

ss -ant sport = :8080 state established | wc -l

Key advantages:

• 5-10x faster than netstat
• Direct kernel socket access
• Supports filter expressions

2. /proc/net/tcp Analysis

For maximum performance on Linux:

awk '$2 ~ /:1F90/ && $4 ~ /06/ {count++} END {print count}' /proc/net/tcp

Where 1F90 is port 8080 in hex (reverse order) and 06 is TCP_ESTABLISHED.

3. eBPF Monitoring

For real-time analytics with minimal overhead:

sudo bpftrace -e 't:syscalls:sys_enter_accept {
  @[args->upeer_sockaddr] = count();
}
END {
  print(@);
}'

For enterprise environments:

• Prometheus + node_exporter: Collects TCP metrics via node_netstat_Tcp_CurrEstab
• Grafana: Visualize connection trends with dashboards
• Conntrack-tools: Netfilter connection tracking

For persistent monitoring with 1-second resolution:

#!/bin/bash
while true; do
  date +%s | tr -d '\n'
  echo " "
  awk 'BEGIN {count=0} $4 == "06" {count++} END {print count}' /proc/net/tcp
  sleep 1
done > connection_count.log

Combine with watch for live terminal viewing:

watch -n1 "awk '\$4 == \"06\" {count++} END {print count}' /proc/net/tcp"

ss -ant sport = :8080 state established | wc -l

# BPFtrace script
bpftrace -e 'tcp:connect {
    @[args->sport, args->dport] = count();
}
interval:s:1 {
    print(@);
    clear(@);
}'

# Install conntrack
sudo apt install conntrack

# Monitor specific port
conntrack -L -p tcp --dport 8080 --state ESTABLISHED | wc -l

#!/bin/bash
watch -n 1 "ss -o state established '( sport = :8080 )' | wc -l"