5xx Server Error

HTTP 504 Gateway Timeout

The server, while acting as a gateway or proxy, did not get a response in time from the upstream server. The backend took too long to respond, and the gateway gave up waiting.

Common Causes

  • Backend server is too slow to respond
  • Long-running database query or computation
  • Network latency between proxy and backend
  • Upstream server is deadlocked or hung

How to Fix

  1. 1Increase gateway/proxy timeout settings
  2. 2Optimize slow backend operations and database queries
  3. 3Add caching to reduce backend load
  4. 4Break long operations into async jobs returning 202

Example

HTTP 504 Gateway Timeout
GET /api/report HTTP/1.1 → Nginx (proxy, 30s timeout)
→ Backend takes 60s to generate report
→ 504 Gateway Timeout

Related Server Error Codes