nginx config_error ai_generated true

upstream sent too big header while reading response header

ID: nginx/proxy-buffer-error

Also available as: JSON · Markdown
85%Fix Rate
88%Confidence
3Evidence
2023-01-01First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
1 active — — —

Root Cause

Response headers from upstream exceed proxy buffer size.

generic

Workarounds

  1. 90% success Increase proxy_buffer_size to 8k or 16k for header-heavy responses 
    proxy_buffer_size 16k; proxy_buffers 4 16k;
  2. 85% success Reduce upstream response header size (fewer cookies, shorter tokens)

Dead Ends

Common approaches that don't work:

  1. Set proxy_buffer_size extremely large 72% fail

    Memory waste per connection

  2. Disable proxy buffering entirely 75% fail

    Memory spike on large responses