Mercurial > hg > nginx-quic
comparison src/http/ngx_http_upstream.h @ 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 | d15a00e6d9e6 |
children | d620f497c50f |
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4384:a8b6d5dee539 | 4385:70ba81827472 |
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163 | 163 |
164 ngx_uint_t cache_min_uses; | 164 ngx_uint_t cache_min_uses; |
165 ngx_uint_t cache_use_stale; | 165 ngx_uint_t cache_use_stale; |
166 ngx_uint_t cache_methods; | 166 ngx_uint_t cache_methods; |
167 | 167 |
168 ngx_flag_t cache_lock; | |
169 ngx_msec_t cache_lock_timeout; | |
170 | |
168 ngx_array_t *cache_valid; | 171 ngx_array_t *cache_valid; |
169 ngx_array_t *cache_bypass; | 172 ngx_array_t *cache_bypass; |
170 ngx_array_t *no_cache; | 173 ngx_array_t *no_cache; |
171 #endif | 174 #endif |
172 | 175 |