networking http ai_generated true

HTTP/1.1 408 Request Timeout

ID: networking/http-408-timeout

Also available as: JSON · Markdown
87%Fix Rate
88%Confidence
50Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
any active — — —

Root Cause

The server closed the connection because the client did not send a complete request within the server's timeout period. This commonly occurs with slow clients, large uploads over poor connections, or idle keep-alive connections being reaped.

generic

Workarounds

  1. 88% success Increase the server request timeout to a reasonable value that accommodates expected client latency 
    1. In nginx: client_header_timeout 60s; client_body_timeout 60s;
2. In Apache: Timeout 60; RequestReadTimeout header=20-40,minrate=500 body=20-60,minrate=500
3. Measure typical client request times from access logs
4. Set timeout to 2-3x the 99th percentile request time
5. Reload the server: systemctl reload nginx
  2. 85% success Use chunked transfer encoding for large uploads to keep the connection active 
    1. Configure the client to use chunked transfer encoding: Transfer-Encoding: chunked
2. Send data in smaller chunks so the server sees activity within its timeout window
3. For file uploads, use multipart form data with progress tracking
4. If behind a load balancer, ensure it also supports chunked encoding and has appropriate idle timeouts

Dead Ends

Common approaches that don't work:

  1. Retry the exact same request immediately without checking client-side issues 70% fail

    If the client is genuinely slow (poor network, large payload), immediate retry will hit the same timeout. The underlying cause — slow upload speed, network congestion, or oversized request — must be addressed.

  2. Increase server request timeout to very large values 65% fail

    Very large timeouts allow slow clients to hold connections open indefinitely, consuming server resources. Under load, this can lead to connection pool exhaustion and denial of service for legitimate fast clients.

Error Chain

Leads to:
Preceded by:
Frequently confused with: