your HTTP request connection start duration too long

发布于:2025-02-26 ⋅ 阅读:(14) ⋅ 点赞:(0)

If your HTTP request connection start duration is taking more than 7 seconds, here are some possible causes and troubleshooting steps:

Possible Causes:

  1. Network Latency – Slow internet or network congestion.
  2. DNS Resolution Delay – Slow DNS lookup affecting the connection initiation.
  3. Proxy or VPN Issues – Additional routing causing delays.
  4. Server Response Delay – The destination server is slow to respond.
  5. TCP Handshake Delay – Slow three-way handshake due to network or server issues.
  6. TLS/SSL Handshake Delay – Issues with SSL negotiation.
  7. High System Load – If the client machine is overloaded, connections may take longer.
  8. Firewall or Security Software – Could be inspecting or delaying the request.

Troubleshooting Steps:

1. Check Network Latency

Run the following command to check latency to the target server:

ping <server-ip>

If response times are high, network congestion or routing issues could be the cause.

2. Perform a Traceroute

To check where the delay occurs:

traceroute <server-ip> # Linux/macOS tracert <server-ip> # Windows

This helps identify if the issue is at the client, ISP, or server level.

3. Measure DNS Resolution Time

Test DNS lookup speed:

nslookup <server-url>

or

dig <server-url>

If it's slow, try using a faster DNS provider like Google (8.8.8.8) or Cloudflare (1.1.1.1).

4. Test Connection Time with curl

Check how long each phase of the request takes:

curl -o /dev/null -s -w "DNS Lookup: %{time_namelookup}\nTCP Handshake: %{time_connect}\nSSL Handshake: %{time_appconnect}\nTransfer Start: %{time_starttransfer}\nTotal Time: %{time_total}\n" https://your-url.com

This will help you pinpoint whether the delay is in DNS, TCP, SSL, or response time.

5. Check for Proxy or VPN Issues
  • If using a proxy or VPN, disable it and test again.
  • If behind a corporate proxy, check its logs for delays.
6. Optimize TLS/SSL Handshake
  • If using HTTPS, check SSL negotiation time with:

    openssl s_client -connect <server-url>:443 -debug

  • Ensure the server supports modern ciphers and TLS 1.2+ for faster handshakes.
7. Increase Connection Pooling (for Java, Spring, etc.)

If you're using a Java application, enable HTTP connection pooling to reduce repeated handshakes:

PoolingHttpClientConnectionManager cm = new PoolingHttpClientConnectionManager(); cm.setMaxTotal(100); // Set max connections CloseableHttpClient httpClient = HttpClients.custom().setConnectionManager(cm).build();

8. Debug with Wireshark or TCPDump

Capture packets to analyze network delays:

tcpdump -i eth0 host <server-ip>

Or use Wireshark to inspect TCP handshake and SSL negotiation.


Next Steps:

  • If the issue is with the server, optimize server response times.
  • If network-related, switch networks (e.g., mobile hotspot) and test again.
  • If using a cloud service (e.g., AWS, Azure), check their status pages for outages.