From: Stefan Eissing Date: Thu, 18 Feb 2016 09:38:40 +0000 (+0000) Subject: doc patch by luca X-Git-Tag: 2.5.0-alpha~2049 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2c43ef0470b936e240974bd9b4eba92a57b37682;p=thirdparty%2Fapache%2Fhttpd.git doc patch by luca git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1731028 13f79535-47bb-0310-9956-ffa450edef68 --- diff --git a/docs/manual/mod/mod_http2.xml b/docs/manual/mod/mod_http2.xml index 6eeb1b013a9..fc249fd327e 100644 --- a/docs/manual/mod/mod_http2.xml +++ b/docs/manual/mod/mod_http2.xml @@ -30,8 +30,8 @@ Available in version 2.4.17 and later -

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.

@@ -53,24 +53,7 @@ -
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.
-
+
How it works
HTTP/2 Dimensioning

@@ -93,8 +76,8 @@ 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 @@ -102,12 +85,12 @@ 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 @@ -115,14 +98,14 @@ 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, @@ -130,7 +113,7 @@ 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 @@ -166,7 +149,28 @@ 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.
+
+
+ H2Direct H2 Direct Protocol Switch