Mercurial > hg > nginx-quic
comparison src/http/ngx_http_upstream.c @ 4385:70ba81827472
Cache locks initial implementation.
New directives: proxy_cache_lock on/off, proxy_cache_lock_timeout. With
proxy_cache_lock set to on, only one request will be allowed to go to
upstream for a particular cache item. Others will wait for a response
to appear in cache (or cache lock released) up to proxy_cache_lock_timeout.
Waiting requests will recheck if they have cached response ready (or are
allowed to run) every 500ms.
Note: we intentionally don't intercept NGX_DECLINED possibly returned by
ngx_http_file_cache_read(). This needs more work (possibly safe, but needs
further investigation). Anyway, it's exceptional situation.
Note: probably there should be a way to disable caching of responses
if there is already one request fetching resource to cache (without waiting
at all). Two possible ways include another cache lock option ("no_cache")
or using proxy_no_cache with some supplied variable.
Note: probably there should be a way to lock updating requests as well. For
now "proxy_cache_use_stale updating" is available.
author | Maxim Dounin <mdounin@mdounin.ru> |
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date | Mon, 26 Dec 2011 11:15:23 +0000 |
parents | f31146f282fd |
children | d620f497c50f |
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4384:a8b6d5dee539 | 4385:70ba81827472 |
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705 | 705 |
706 c->min_uses = u->conf->cache_min_uses; | 706 c->min_uses = u->conf->cache_min_uses; |
707 c->body_start = u->conf->buffer_size; | 707 c->body_start = u->conf->buffer_size; |
708 c->file_cache = u->conf->cache->data; | 708 c->file_cache = u->conf->cache->data; |
709 | 709 |
710 c->lock = u->conf->cache_lock; | |
711 c->lock_timeout = u->conf->cache_lock_timeout; | |
712 | |
710 u->cache_status = NGX_HTTP_CACHE_MISS; | 713 u->cache_status = NGX_HTTP_CACHE_MISS; |
711 } | 714 } |
712 | 715 |
713 rc = ngx_http_file_cache_open(r); | 716 rc = ngx_http_file_cache_open(r); |
714 | 717 |