From: Luca Toscano Date: Thu, 18 Feb 2016 13:49:31 +0000 (+0000) Subject: Documentation rebuild. X-Git-Tag: 2.5.0-alpha~2047 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=36dc711fa165223313e1e98fb75e342419324563;p=thirdparty%2Fapache%2Fhttpd.git Documentation rebuild. git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1731075 13f79535-47bb-0310-9956-ffa450edef68 --- diff --git a/docs/manual/mod/mod_http2.html.en b/docs/manual/mod/mod_http2.html.en index 667eb5909df..8d72da30fbb 100644 --- a/docs/manual/mod/mod_http2.html.en +++ b/docs/manual/mod/mod_http2.html.en @@ -35,8 +35,8 @@ Compatibility:Available in version 2.4.17 and later

Summary

-

This module provides HTTP/2 (RFC 7540) support for the Apache - HTTP Server.

+

This module provides HTTP/2 (RFC 7540) + support for the Apache HTTP Server.

This module relies on libnghttp2 to provide the core http/2 engine.

@@ -57,9 +57,7 @@

Topics

Directives

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-

Environment Variables

-

- This module can be configured to provide HTTP/2 related information - as additional environment variables to the SSI and CGI namespace. -

- - - - - - - - - - -
Variable Name:Value Type:Description:
HTTP2flagHTTP/2 is being used.
H2PUSHflagHTTP/2 Server Push is enabled for this request and also supported by the client.
-
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-
-

HTTP/2 Dimensioning

+

How it works

+ +

HTTP/2 Dimensioning

Enabling HTTP/2 on your Apache Server has impact on the resource consumption and if you have a busy site, you may need to consider @@ -121,8 +103,8 @@ workers, or shorter H2Workers, will not show up in mod_status. They are also not counted against directives such as ThreadsPerChild. However they take ThreadsPerChild as default if you have not configured something - else via <H2MinWorkers> and - <H2MaxWorkers>. + else via H2MinWorkers and + H2MaxWorkers.

Another thing to watch out for is is memory consumption. Since HTTP/2 @@ -130,12 +112,12 @@ for and dependencies between them, it will always need more memory than HTTP/1.1 processing. There are three directives which steer the memory footprint of a HTTP/2 connection: - <H2MaxSessionStreams>, - <H2WindowSize> and - <H2StreamMaxMemSize>. + H2MaxSessionStreams, + H2WindowSize and + H2StreamMaxMemSize.

- <H2MaxSessionStreams> limits the + H2MaxSessionStreams limits the number of parallel requests that a client can make on a HTTP/2 connection. It depends on your site how many you should allow. The default is 100 which is plenty and unless you run into memory problems, I would keep it this @@ -143,14 +125,14 @@ use up only a little bit of memory until the actual processing starts.

- <H2WindowSize> controls how much + H2WindowSize controls how much the client is allowed to send as body of a request, before it waits for the server to encourage more. Or, the other way around, it is the amount of request body data the server needs to be able to buffer. This is per request.

- And last, but not least, <H2StreamMaxMemSize> + And last, but not least, H2StreamMaxMemSize controls how much response data shall be buffered. The request sits in a H2Worker thread and is producing data, the HTTP/2 connection tries to send this to the client. If the client does not read fast enough, @@ -158,7 +140,7 @@ H2Worker.

- If you serve a lot of static files, <H2SessionExtraFiles> + If you serve a lot of static files, H2SessionExtraFiles is of interest. This tells the server how many file handles per HTTP/2 connection it is allowed to waste for better performance. Because when a request produces a static file as the response, the file handle @@ -168,9 +150,9 @@ and if too many are used this way, requests may fail under load as the amount of open handles has been exceeded.

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Multiple Hosts and Misdirected Requests

+ + +

Multiple Hosts and Misdirected Requests

Many sites use the same TLS certificate for multiple virtual hosts. The certificate either has a wildcard name, such as '*.example.org' or carries @@ -193,6 +175,26 @@ If you mix things, Apache httpd will detect it and return a special response code, 421 Misidrected Request, to the client.

+ + +

Environment Variables

+

+ This module can be configured to provide HTTP/2 related information + as additional environment variables to the SSI and CGI namespace. +

+ + + + + + + + + + +
Variable Name:Value Type:Description:
HTTP2flagHTTP/2 is being used.
H2PUSHflagHTTP/2 Server Push is enabled for this request and also supported by the client.
+ +
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H2Direct Directive