changeset 7702:7015f26aef90

Cache: ignore stale-if-error for 4xx and 5xx codes. Previously the stale-if-error extension of the Cache-Control upstream header triggered the return of a stale response for all error conditions that can be specified in the proxy_cache_use_stale directive. The list of these errors includes both network/timeout/format errors, as well as some HTTP codes like 503, 504, 403, 429 etc. The latter prevented a cache entry from being updated by a response with any of these HTTP codes during the stale-if-error period. Now stale-if-error only works for network/timeout/format errors and ignores the upstream HTTP code. The return of a stale response for certain HTTP codes is still possible using the proxy_cache_use_stale directive. This change also applies to the stale-while-revalidate extension of the Cache-Control header, which triggers stale-if-error if it is missing. Reported at
author Roman Arutyunyan <>
date Wed, 29 Jul 2020 13:28:04 +0300
parents 8ca47f094d5b
children da5e3f5b1673
files src/http/ngx_http_upstream.c
diffstat 1 files changed, 1 insertions(+), 1 deletions(-) [+]
line wrap: on
line diff
--- a/src/http/ngx_http_upstream.c	Fri Aug 14 12:45:52 2020 +0300
+++ b/src/http/ngx_http_upstream.c	Wed Jul 29 13:28:04 2020 +0300
@@ -2473,7 +2473,7 @@
         if (u->cache_status == NGX_HTTP_CACHE_EXPIRED
-            && ((u->conf->cache_use_stale & un->mask) || r->cache->stale_error))
+            && (u->conf->cache_use_stale & un->mask))
             ngx_int_t  rc;