From: Luca Toscano Date: Sat, 8 Feb 2020 17:26:11 +0000 (+0000) Subject: documentation rebuild [skip ci] X-Git-Tag: 2.4.42~113 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=67631dfae067aa1363424b28b13e79cfaa849627;p=thirdparty%2Fapache%2Fhttpd.git documentation rebuild [skip ci] git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1873802 13f79535-47bb-0310-9956-ffa450edef68 --- diff --git a/docs/man/fcgistarter.8 b/docs/man/fcgistarter.8 index 20e791659ca..7440fd7dd16 100644 --- a/docs/man/fcgistarter.8 +++ b/docs/man/fcgistarter.8 @@ -19,7 +19,7 @@ .el .ne 3 .IP "\\$1" \\$2 .. -.TH "FCGISTARTER" 8 "2018-07-06" "Apache HTTP Server" "fcgistarter" +.TH "FCGISTARTER" 8 "2020-02-08" "Apache HTTP Server" "fcgistarter" .SH NAME fcgistarter \- Start a FastCGI program @@ -46,7 +46,7 @@ Currently only works on Unix systems\&. .TP \fB-c \fIcommand\fR\fR -FastCGI program +Absolute path of the FastCGI program .TP \fB-p \fIport\fR\fR Port which the program will listen on diff --git a/docs/manual/developer/modguide.html.en b/docs/manual/developer/modguide.html.en index eb8f4b811b2..a3839f4fbcb 100644 --- a/docs/manual/developer/modguide.html.en +++ b/docs/manual/developer/modguide.html.en @@ -182,7 +182,7 @@ the server based on the value of this tag.

Hooking into httpd

-To begin with, we only want to create a simple handler, that replies to the +To begin with, we only want to create a simple handler that replies to the client browser when a specific URL is requested, so we won't bother setting up configuration handlers and directives just yet. Our initial module definition will look like this:

@@ -210,7 +210,7 @@ just want to hook onto the requests and possibly handle some of them.

is the name of a function we will create to manage how we hook onto the request process. In this example module, the function has just one purpose; To create a simple hook that gets called after all the rewrites, access -control etc has been handled. Thus, we will let the server know, that we want +control etc has been handled. Thus, we will let the server know that we want to hook into its process as one of the last modules:

diff --git a/docs/manual/index.html.en b/docs/manual/index.html.en index 53289422995..60e00ccadb2 100644 --- a/docs/manual/index.html.en +++ b/docs/manual/index.html.en @@ -38,7 +38,7 @@ Documentation  tr  |  zh-cn 

-

+

+ persist across internal redirects. A read-only lua table suitable for iteration is available as r:err_headers_out_table(). @@ -493,13 +493,13 @@ end + User-Agent, Referer and so on. A read-only lua table suitable for iteration is available as r:headers_in_table(). - + @@ -541,7 +541,7 @@ end - + @@ -608,7 +608,7 @@ end - + diff --git a/docs/manual/mod/mod_status.html.en b/docs/manual/mod/mod_status.html.en index 77570a7c5a0..537536e611d 100644 --- a/docs/manual/mod/mod_status.html.en +++ b/docs/manual/mod/mod_status.html.en @@ -49,9 +49,9 @@ performance

The details given are:

Release Notes

  • New features with Apache 2.3/2.4
  • New features with Apache 2.1/2.2
    • diff --git a/docs/manual/mod/allmodules.xml b/docs/manual/mod/allmodules.xml index b0e65d9e3ce..8fdd483eaa5 100644 --- a/docs/manual/mod/allmodules.xml +++ b/docs/manual/mod/allmodules.xml @@ -118,6 +118,7 @@ mod_status.xml mod_substitute.xml mod_suexec.xml + mod_systemd.xml mod_unique_id.xml mod_unixd.xml mod_userdir.xml diff --git a/docs/manual/mod/allmodules.xml.de b/docs/manual/mod/allmodules.xml.de index 5fa1c419549..fc9a3aecc33 100644 --- a/docs/manual/mod/allmodules.xml.de +++ b/docs/manual/mod/allmodules.xml.de @@ -118,6 +118,7 @@ mod_status.xml mod_substitute.xml mod_suexec.xml + mod_systemd.xml mod_unique_id.xml mod_unixd.xml mod_userdir.xml diff --git a/docs/manual/mod/allmodules.xml.es b/docs/manual/mod/allmodules.xml.es index fbc7a76d187..db82b11cb50 100644 --- a/docs/manual/mod/allmodules.xml.es +++ b/docs/manual/mod/allmodules.xml.es @@ -118,6 +118,7 @@ mod_status.xml mod_substitute.xml mod_suexec.xml + mod_systemd.xml mod_unique_id.xml mod_unixd.xml mod_userdir.xml diff --git a/docs/manual/mod/allmodules.xml.fr b/docs/manual/mod/allmodules.xml.fr index b0d16b4e204..71c021f0f24 100644 --- a/docs/manual/mod/allmodules.xml.fr +++ b/docs/manual/mod/allmodules.xml.fr @@ -118,6 +118,7 @@ mod_status.xml.fr mod_substitute.xml.fr mod_suexec.xml.fr + mod_systemd.xml.fr mod_unique_id.xml.fr mod_unixd.xml.fr mod_userdir.xml.fr diff --git a/docs/manual/mod/allmodules.xml.ja b/docs/manual/mod/allmodules.xml.ja index 223e9bd7bfd..50afa31691d 100644 --- a/docs/manual/mod/allmodules.xml.ja +++ b/docs/manual/mod/allmodules.xml.ja @@ -118,6 +118,7 @@ mod_status.xml.ja mod_substitute.xml mod_suexec.xml.ja + mod_systemd.xml mod_unique_id.xml.ja mod_unixd.xml mod_userdir.xml.ja diff --git a/docs/manual/mod/allmodules.xml.ko b/docs/manual/mod/allmodules.xml.ko index 224514242a0..c811120a4b6 100644 --- a/docs/manual/mod/allmodules.xml.ko +++ b/docs/manual/mod/allmodules.xml.ko @@ -118,6 +118,7 @@ mod_status.xml.ko mod_substitute.xml mod_suexec.xml.ko + mod_systemd.xml mod_unique_id.xml.ko mod_unixd.xml mod_userdir.xml.ko diff --git a/docs/manual/mod/allmodules.xml.tr b/docs/manual/mod/allmodules.xml.tr index dc392d216fb..d94c89f1aad 100644 --- a/docs/manual/mod/allmodules.xml.tr +++ b/docs/manual/mod/allmodules.xml.tr @@ -118,6 +118,7 @@ mod_status.xml.tr mod_substitute.xml mod_suexec.xml.tr + mod_systemd.xml mod_unique_id.xml mod_unixd.xml.tr mod_userdir.xml.tr diff --git a/docs/manual/mod/allmodules.xml.zh-cn b/docs/manual/mod/allmodules.xml.zh-cn index b0e65d9e3ce..8fdd483eaa5 100644 --- a/docs/manual/mod/allmodules.xml.zh-cn +++ b/docs/manual/mod/allmodules.xml.zh-cn @@ -118,6 +118,7 @@ mod_status.xml mod_substitute.xml mod_suexec.xml + mod_systemd.xml mod_unique_id.xml mod_unixd.xml mod_userdir.xml diff --git a/docs/manual/mod/event.html.en b/docs/manual/mod/event.html.en index e6c7661bdeb..cc8205723ab 100644 --- a/docs/manual/mod/event.html.en +++ b/docs/manual/mod/event.html.en @@ -118,24 +118,29 @@ of the AsyncRequestWorkerFactor.

    The status page of mod_status shows new columns under the Async connections section:

    Writing
    -
    While sending the response to the client, it might happen that the TCP write buffer fills up because the connection is too slow. Usually in this case a write() to the socket returns EWOULDBLOCK or EAGAIN, to become writable again after an idle time. The worker holding the socket might be able to offload the waiting task to the listener thread, that in turn will re-assign it to the first idle worker thread available once an event will be raised for the socket (for example, "the socket is now writable"). Please check the Limitations section for more information. +
    While sending the response to the client, it might happen that the TCP write buffer fills up because the connection is too slow. + Usually in this case, a write() to the socket returns EWOULDBLOCK or EAGAIN to become writable again after an idle time. + The worker holding the socket might be able to offload the waiting task to the listener thread, that in turn will re-assign it to the first idle worker thread available once an event will be raised for the socket (for example, "the socket is now writable"). + Please check the Limitations section for more information.
    Keep-alive
    Keep Alive handling is the most basic improvement from the worker MPM. Once a worker thread finishes to flush the response to the client, it can offload the - socket handling to the listener thread, that in turns will wait for any event from the + socket handling to the listener thread, that in turn will wait for any event from the OS, like "the socket is readable". If any new request comes from the client, then the listener will forward it to the first worker thread available. Conversely, if the KeepAliveTimeout occurs then the socket will be - closed by the listener. In this way the worker threads are not responsible for idle - sockets and they can be re-used to serve other requests.
    + closed by the listener. In this way, the worker threads are not responsible for idle + sockets, and they can be re-used to serve other requests.
    Closing
    Sometimes the MPM needs to perform a lingering close, namely sending back an early error to the client while it is still transmitting data to httpd. Sending the response and then closing the connection immediately is not the correct thing to do since the client (still trying to send the rest of the - request) would get a connection reset and could not read the httpd's response. The lingering close is time bounded but it can take relatively long - time, so it's offloaded to a worker thread (including the shutdown hooks and real socket close). From 2.4.28 onward this is also the + request) would get a connection reset and could not read the httpd's response. + The lingering close is time-bounded, but it can take a relatively long + time, so it's offloaded to a worker thread (including the shutdown hooks and real socket close). + From 2.4.28 onward, this is also the case when connections finally timeout (the listener thread never handles connections besides waiting for and dispatching their events).
    @@ -145,33 +150,33 @@ of the AsyncRequestWorkerFactor.

    Graceful process termination and Scoreboard usage

    -

    This mpm showed some scalability bottlenecks in the past leading to the following +

    This mpm showed some scalability bottlenecks in the past, leading to the following error: "scoreboard is full, not at MaxRequestWorkers". MaxRequestWorkers limits the number of simultaneous requests that will be served at any given time and also the number of allowed processes (MaxRequestWorkers - / ThreadsPerChild), meanwhile + / ThreadsPerChild); meanwhile, the Scoreboard is a representation of all the running processes and the status of their worker threads. If the scoreboard is full (so all the threads have a state that is not idle) but the number of active requests served is not MaxRequestWorkers, it means that some of them are blocking new requests that could be served but that are queued instead (up to the limit imposed by - ListenBacklog). Most of the times + ListenBacklog). Most of the time, the threads are stuck in the Graceful state, namely they are waiting to finish their work with a TCP connection to safely terminate and free up a - scoreboard slot (for example handling long running requests, slow clients + scoreboard slot (for example, handling long-running requests, slow clients or connections with keep-alive enabled). Two scenarios are very common:

      -
    • During a graceful restart. - The parent process signals all its children to complete +
    • During a graceful restart, + the parent process signals all its children to complete their work and terminate, while it reloads the config and forks new processes. If the old children keep running for a while before stopping, the scoreboard will be partially occupied until their slots are freed.
      • -
    • When the server load goes down in a way that causes httpd to - stop some processes (for example due to +
    • The server load goes down in a way that causes httpd to + stop some processes (for example, due to MaxSpareThreads). This is particularly problematic because when the load increases again, httpd will try to start new processes. @@ -187,7 +192,7 @@ of the AsyncRequestWorkerFactor.

      ServerLimit. MaxRequestWorkers and ThreadsPerChild are used - to limit the amount of active processes, meanwhile + to limit the amount of active processes; meanwhile, ServerLimit takes also into account the ones doing a graceful close to allow extra slots when needed. The idea is to use @@ -200,7 +205,7 @@ of the AsyncRequestWorkerFactor.

    • During graceful shutdown, if there are more running worker threads than open connections for a given process, terminate these threads to free resources faster (which may be needed for new processes).
      • -
    • If the scoreboard is full, prevent more processes to finish +
    • If the scoreboard is full, prevent more processes from finishing gracefully due to reduced load until old processes have terminated (otherwise the situation would get worse once the load increases again).
    @@ -224,14 +229,14 @@ of the AsyncRequestWorkerFactor.

    data, and the amount of data produced by the filter is too big to be buffered in memory, the thread used for the request is not freed while httpd waits until the pending data is sent to the client.
    - To illustrate this point we can think about the following two situations: + To illustrate this point, we can think about the following two situations: serving a static asset (like a CSS file) versus serving content retrieved from FCGI/CGI or a proxied server. The former is predictable, namely the event MPM has full visibility on the end of the content and it can use events: the worker thread serving the response content can flush the first bytes until EWOULDBLOCK or EAGAIN is returned, delegating the rest to the listener. This one in turn - waits for an event on the socket, and delegates the work to flush the rest of the content - to the first idle worker thread. Meanwhile in the latter example (FCGI/CGI/proxied content) + waits for an event on the socket and delegates the work to flush the rest of the content + to the first idle worker thread. Meanwhile in the latter example (FCGI/CGI/proxied content), the MPM can't predict the end of the response and a worker thread has to finish its work before returning the control to the listener. The only alternative is to buffer the response in memory, but it wouldn't be the safest option for the sake of the @@ -249,7 +254,7 @@ of the AsyncRequestWorkerFactor.

Before these new APIs where made available, the traditional select and poll APIs had to be used. Those APIs get slow if used to handle many connections or if the set of connections rate of change is high. - The new APIs allow to monitor much more connections and they perform way better when the set of connections to monitor changes frequently. So these APIs made it possible to write the event MPM, that scales much better with the typical HTTP pattern of many idle connections.

+ The new APIs allow to monitor many more connections, and they perform way better when the set of connections to monitor changes frequently. So these APIs made it possible to write the event MPM, that scales much better with the typical HTTP pattern of many idle connections.

The MPM assumes that the underlying apr_pollset implementation is reasonably threadsafe. This enables the MPM to @@ -279,7 +284,7 @@ of the AsyncRequestWorkerFactor.

  • To use this MPM on FreeBSD, FreeBSD 5.3 or higher is recommended. - However, it is possible to run this MPM on FreeBSD 5.2.1, if you + However, it is possible to run this MPM on FreeBSD 5.2.1 if you use libkse (see man libmap.conf).
  • For NetBSD, at least version 2.0 is recommended.
    • @@ -310,9 +315,9 @@ of the AsyncRequestWorkerFactor.

    To mitigate this problem, the event MPM does two things:

      -
    • it limits the number of connections accepted per process, depending on the +
    • It limits the number of connections accepted per process, depending on the number of idle request workers;
      • -
    • if all workers are busy, it will +
    • If all workers are busy, it will close connections in keep-alive state even if the keep-alive timeout has not expired. This allows the respective clients to reconnect to a different process which may still have worker threads available.
      • diff --git a/docs/manual/mod/index.html.en b/docs/manual/mod/index.html.en index d9cdc556e19..c12340dded5 100644 --- a/docs/manual/mod/index.html.en +++ b/docs/manual/mod/index.html.en @@ -241,6 +241,7 @@ performance
      mod_substitute
      Perform search and replace operations on response bodies
      mod_suexec
      Allows CGI scripts to run as a specified user and Group
      +
      mod_systemd
      Provides better support for systemd integration
      mod_unique_id
      Provides an environment variable with a unique identifier for each request
      mod_unixd
      Basic (required) security for Unix-family platforms.
      diff --git a/docs/manual/mod/mod_lua.html.en b/docs/manual/mod/mod_lua.html.en index 09d85200c1e..1ab66d33a46 100644 --- a/docs/manual/mod/mod_lua.html.en +++ b/docs/manual/mod/mod_lua.html.en @@ -467,7 +467,7 @@ end
table no MIME header environment for the response, printed even on errors and - persist across internal redirects
filename table yes MIME header environment from the request. This contains headers such as Host, - User-Agent, Referer and so on.
headers_out table yesMIME header environment for the response.MIME header environment for the response. A read-only lua table suitable for iteration is available as r:headers_out_table().
hostname notes table yesA list of notes that can be passed on from one module to another.A list of notes that can be passed on from one module to another. A read-only lua table suitable for iteration is available as r:notes_table().
options subprocess_env table yesThe environment variables set for this request.The environment variables set for this request. A read-only lua table suitable for iteration is available as r:subprocess_env_table().
started
+ + + +
Description:Provides better support for systemd integration
Status:Extension
Module Identifier:systemd_module
Source File:mod_systemd.c
Compatibility:Available in Apache 2.4.42 and later
+

Summary

+ +

This module provides support for systemd integration. It allows + httpd to be used in a service with the systemd + Type=notify (see systemd.service(5) + for more information). The module is activated if loaded.

+ +

ExtendedStatus is + enabled by default if the module is loaded. If ExtendedStatus is not disabled in + the configuration, run-time load and request statistics are made + available in the systemctl status output.

+ +
Support Apache!

Directives

+

This module provides no + directives.

+

Bugfix checklist

See also

+
+ + +
+

Available Languages:  en  | + fr 

+
top

Comments

Notice:
This is not a Q&A section. Comments placed here should be pointed towards suggestions on improving the documentation or server, and may be removed by our moderators if they are either implemented or considered invalid/off-topic. Questions on how to manage the Apache HTTP Server should be directed at either our IRC channel, #httpd, on Freenode, or sent to our mailing lists.
+
+ \ No newline at end of file diff --git a/docs/manual/mod/mod_systemd.xml.meta b/docs/manual/mod/mod_systemd.xml.meta new file mode 100644 index 00000000000..edb0b7cbc9b --- /dev/null +++ b/docs/manual/mod/mod_systemd.xml.meta @@ -0,0 +1,13 @@ + + + + + mod_systemd + /mod/ + .. + + + en + fr + + diff --git a/docs/manual/mod/mpm_common.html.en b/docs/manual/mod/mpm_common.html.en index 66b0e913a5f..6b6316e66cf 100644 --- a/docs/manual/mod/mpm_common.html.en +++ b/docs/manual/mod/mpm_common.html.en @@ -255,8 +255,8 @@ including other causes. Module:event, worker, prefork, mpm_winnt, mpm_netware, mpmt_os2

The maximum length of the queue of pending connections. - Generally no tuning is needed or desired, however on some - systems it is desirable to increase this when under a TCP SYN + Generally no tuning is needed or desired; however on some + systems, it is desirable to increase this when under a TCP SYN flood attack. See the backlog parameter to the listen(2) system call.

@@ -360,7 +360,7 @@ will handle during its life 0, then the process will never expire.

Setting MaxConnectionsPerChild to a - non-zero value limits the amount of memory that process can consume + non-zero value limits the amount of memory that a process can consume by (accidental) memory leakage.

@@ -408,9 +408,9 @@ simultaneously ServerLimit.

For threaded and hybrid servers (e.g. event - or worker) MaxRequestWorkers restricts + or worker), MaxRequestWorkers restricts the total number of threads that will be available to serve clients. - For hybrid MPMs the default value is 16 (ServerLimit) multiplied by the value of + For hybrid MPMs, the default value is 16 (ServerLimit) multiplied by the value of 25 (ThreadsPerChild). Therefore, to increase MaxRequestWorkers to a value that requires more than 16 processes, you must also raise ServerLimit.

@@ -435,7 +435,7 @@ simultaneously

For worker and event, the default is MaxSpareThreads 250. These MPMs deal with idle threads on a server-wide basis. If there are too many idle threads in the - server then child processes are killed until the number of idle + server, then child processes are killed until the number of idle threads is less than this number. Additional processes/threads might be created if ListenCoresBucketsRatio is enabled.

@@ -486,7 +486,7 @@ spikes

worker and event use a default of MinSpareThreads 75 and deal with idle threads on a server-wide - basis. If there aren't enough idle threads in the server then child + basis. If there aren't enough idle threads in the server, then child processes are created until the number of idle threads is greater than number. Additional processes/threads might be created if ListenCoresBucketsRatio @@ -494,7 +494,7 @@ spikes

mpm_netware uses a default of MinSpareThreads 10 and, since it is a single-process - MPM, tracks this on a server-wide bases.

+ MPM, tracks this on a server-wide basis.

mpmt_os2 works similar to mpm_netware. For @@ -520,7 +520,7 @@ of the daemon

The PidFile directive sets the file to which the server records the process id of the daemon. If the - filename is not absolute then it is assumed to be relative to the + filename is not absolute, then it is assumed to be relative to the ServerRoot.

Example

PidFile /var/run/apache.pid
@@ -583,7 +583,7 @@ the child processes

File-based shared memory is useful for third-party applications that require direct access to the scoreboard.

-

If you use a ScoreBoardFile then +

If you use a ScoreBoardFile, then you may see improved speed by placing it on a RAM disk. But be careful that you heed the same warnings about log file placement and security.

@@ -838,7 +838,7 @@ client connections will be achievable if ThreadStackSize is set to a value lower than the operating system default. This type of adjustment should only be made in a test environment which allows - the full set of web server processing can be exercised, as there + the full set of web server processing to be exercised, as there may be infrequent requests which require more stack to process. The minimum required stack size strongly depends on the modules used, but any change in the web server configuration can invalidate diff --git a/docs/manual/new_features_2_4.html.en b/docs/manual/new_features_2_4.html.en index 6bf3c0afa1d..2ae7c7d7ff2 100644 --- a/docs/manual/new_features_2_4.html.en +++ b/docs/manual/new_features_2_4.html.en @@ -208,6 +208,10 @@
mod_socache_redis (available since 2.4.39)
Support Redis based shared object cache provider.
+
mod_systemd (available since 2.4.42)
+
systemd integration. It allows httpd to be used in a service with the systemd + Type=notify.
+
top
diff --git a/docs/manual/new_features_2_4.xml.fr b/docs/manual/new_features_2_4.xml.fr index ac77bf787bc..3271a76c3ce 100644 --- a/docs/manual/new_features_2_4.xml.fr +++ b/docs/manual/new_features_2_4.xml.fr @@ -3,7 +3,7 @@ - + +