Mercurial > hg > nginx-quic
diff 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> |
---|---|
date | Mon, 26 Dec 2011 11:15:23 +0000 |
parents | f31146f282fd |
children | d620f497c50f |
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--- a/src/http/ngx_http_upstream.c +++ b/src/http/ngx_http_upstream.c @@ -707,6 +707,9 @@ ngx_http_upstream_cache(ngx_http_request c->body_start = u->conf->buffer_size; c->file_cache = u->conf->cache->data; + c->lock = u->conf->cache_lock; + c->lock_timeout = u->conf->cache_lock_timeout; + u->cache_status = NGX_HTTP_CACHE_MISS; }