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comparison xml/en/docs/http/ngx_http_proxy_module.xml @ 1912:ec4af97e4403

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Split off header options from parameters in proxy_cache_use_stale and friends.
author Yaroslav Zhuravlev <yar@nginx.com>
date Tue, 21 Feb 2017 21:23:53 +0300
parents 41cf2c2d8c5c
children 66a30a380fba
comparison
equal deleted inserted replaced
1911:f024ac0ec5c7 1912:ec4af97e4403
8 <!DOCTYPE module SYSTEM "../../../../dtd/module.dtd"> 8 <!DOCTYPE module SYSTEM "../../../../dtd/module.dtd">
9 9
10 <module name="Module ngx_http_proxy_module" 10 <module name="Module ngx_http_proxy_module"
11 link="/en/docs/http/ngx_http_proxy_module.html" 11 link="/en/docs/http/ngx_http_proxy_module.html"
12 lang="en" 12 lang="en"
13 rev="56"> 13 rev="57">
14 14
15 <section id="summary"> 15 <section id="summary">
16 16
17 <para> 17 <para>
18 The <literal>ngx_http_proxy_module</literal> module allows passing 18 The <literal>ngx_http_proxy_module</literal> module allows passing
647 647
648 <para> 648 <para>
649 The <literal>error</literal> parameter also permits 649 The <literal>error</literal> parameter also permits
650 using a stale cached response if a proxied server to process a request 650 using a stale cached response if a proxied server to process a request
651 cannot be selected. 651 cannot be selected.
652 The same behavior can be enabled with the
653 “<link url="https://tools.ietf.org/html/rfc5861#section-4">stale-if-error</link>”
654 extension of the <header>Cache-Control</header> response header field (1.11.10)
655 for a specified number of seconds after the response became stale,
656 however, this has lower priority than using the directive parameter.
657 </para> 652 </para>
658 653
659 <para id="proxy_cache_use_stale_updating"> 654 <para id="proxy_cache_use_stale_updating">
660 Additionally, the <literal>updating</literal> parameter permits 655 Additionally, the <literal>updating</literal> parameter permits
661 using a stale cached response if it is currently being updated. 656 using a stale cached response if it is currently being updated.
662 This allows minimizing the number of accesses to proxied servers 657 This allows minimizing the number of accesses to proxied servers
663 when updating cached data. 658 when updating cached data.
664 The same behavior can be enabled with the 659 </para>
660
661 <para>
662 Using a stale cached response
663 can also be enabled directly in the response header
664 for a specified number of seconds after the response became stale (1.11.10).
665 This has lower priority than using the directive parameters.
666 <list type="bullet" compact="no">
667
668 <listitem>
669 The
665 “<link url="https://tools.ietf.org/html/rfc5861#section-3">stale-while-revalidate</link>” 670 “<link url="https://tools.ietf.org/html/rfc5861#section-3">stale-while-revalidate</link>”
666 extension of the <header>Cache-Control</header> response header field (1.11.10) 671 extension of the <header>Cache-Control</header> header field permits
667 for a specified number of seconds after the response became stale, 672 using a stale cached response if it is currently being updated.
668 however, this has lower priority than using the directive parameter. 673 </listitem>
674
675 <listitem>
676 The
677 “<link url="https://tools.ietf.org/html/rfc5861#section-4">stale-if-error</link>”
678 extension of the <header>Cache-Control</header> header field permits
679 using a stale cached response in case of an error.
680 </listitem>
681
682 </list>
669 </para> 683 </para>
670 684
671 <para> 685 <para>
672 To minimize the number of accesses to proxied servers when 686 To minimize the number of accesses to proxied servers when
673 populating a new cache element, the <link id="proxy_cache_lock"/> 687 populating a new cache element, the <link id="proxy_cache_lock"/>