Mercurial > hg > nginx
comparison src/http/ngx_http_cache.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 | d10bcb07d9d4 |
children | d620f497c50f |
comparison
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4384:a8b6d5dee539 | 4385:70ba81827472 |
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77 ngx_buf_t *buf; | 77 ngx_buf_t *buf; |
78 | 78 |
79 ngx_http_file_cache_t *file_cache; | 79 ngx_http_file_cache_t *file_cache; |
80 ngx_http_file_cache_node_t *node; | 80 ngx_http_file_cache_node_t *node; |
81 | 81 |
82 ngx_msec_t lock_timeout; | |
83 ngx_msec_t wait_time; | |
84 | |
85 ngx_event_t wait_event; | |
86 | |
87 unsigned lock:1; | |
88 unsigned waiting:1; | |
89 | |
82 unsigned updated:1; | 90 unsigned updated:1; |
83 unsigned updating:1; | 91 unsigned updating:1; |
84 unsigned exists:1; | 92 unsigned exists:1; |
85 unsigned temp_file:1; | 93 unsigned temp_file:1; |
86 }; | 94 }; |