Apache MPM mpmt

From 8b09ca2ad99ce9eadd7918f03e48bd052856254c Mon Sep 17 00:00:00 2001 From: Joshua Slive Date: Fri, 17 Nov 2000 19:29:59 +0000 Subject: [PATCH] First attempt at MPM documentation. Feedback appreciated. Discussion to follow on apache-docs. git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@86997 13f79535-47bb-0310-9956-ffa450edef68 --- docs/manual/STATUS | 2 + docs/manual/mod/core.html | 403 --------------------------- docs/manual/mod/directives.html | 20 +- docs/manual/mod/index.html | 10 + docs/manual/mod/mpmt_pthread.html | 434 ++++++++++++++++++++++++++++++ 5 files changed, 456 insertions(+), 413 deletions(-) create mode 100644 docs/manual/mod/mpmt_pthread.html diff --git a/docs/manual/STATUS b/docs/manual/STATUS index 1c51832c2b..bc32e1b5cf 100644 --- a/docs/manual/STATUS +++ b/docs/manual/STATUS @@ -13,6 +13,8 @@ apache-docs-subscribe@apache.org on the operation of each MPM. There is also some info in htdocs/manual/mpm.html that will need to be cleaned up, linked up, and updated. + Joshua has committed + an intitial version of mpmt_pthread for discussion. - Merging of changes in 1.3. - There have been many changes in the 1.3 docs which haven't diff --git a/docs/manual/mod/core.html b/docs/manual/mod/core.html index 7119f4dd3f..e222e38d9f 100644 --- a/docs/manual/mod/core.html +++ b/docs/manual/mod/core.html @@ -59,16 +59,10 @@ always available.

ListenBacklog

<LocationMatch> -

LockFile

LogLevel -

MaxClients

MaxKeepAliveRequests -

MaxRequestsPerChild -

MaxSpareServers -

MinSpareServers

NameVirtualHost

Options -

PidFile

Port

Require

ResourceConfig @@ -76,7 +70,6 @@ always available.

RLimitMEM

RLimitNPROC

Satisfy -

ScoreBoardFile

ScriptInterpreterSource

SendBufferSize

ServerAdmin @@ -87,8 +80,6 @@ always available.

TimeOut

UseCanonicalName @@ -517,36 +508,6 @@ CGI scripts, and byte range responses do not have this header.

CoreDumpDirectory directive

- -Syntax: CoreDumpDirectory directory
-Default: the same location as ServerRoot
-Context: server config
-Status: core
-Compatibility: Removed in version 2.0

- -This controls the directory to which Apache attempts to switch before -dumping core. The default is in the ServerRoot -directory, however since this should not be writable by the user -the server runs as, core dumps won't normally get written. If you -want a core dump for debugging, you can use this directive to place -it in a different location.

DefaultType directive

LockFile directive

-Syntax: LockFile filename
-Default: LockFile logs/accept.lock
-Context: server config
-Status: core
-Compatibility: Moved in version 2.0 to the -MPMs.

- -The LockFile directive sets the path to the lockfile used when -Apache is compiled with either USE_FCNTL_SERIALIZED_ACCEPT or -USE_FLOCK_SERIALIZED_ACCEPT. This directive should normally be -left at its default value. The main reason for changing it is if -the logs directory is NFS mounted, since the lockfile -must be stored on a local disk. The PID of the main -server process is automatically appended to the filename.

- -SECURITY: It is best to avoid putting this file in a -world writable directory such as /var/tmp because someone -could create a denial of service attack and prevent the server from -starting by creating a lockfile with the same name as the one the -server will try to create.

- -

LogLevel directive

E.g., when Using a level of at least crit is recommended.

MaxClients directive

- -Syntax: MaxClients number
-Default: MaxClients 256
-Context: server config
-Status: core
-Compatibility: Moved in version 2.0 to the -MPMs.

- -

The MaxClients directive sets the limit on the number of simultaneous -requests that can be supported; not more than this number of child server -processes will be created. To configure more than 256 clients, you must -edit the HARD_SERVER_LIMIT entry in httpd.h and recompile. - -

Any connection attempts over the MaxClients limit will normally -be queued, up to a number based on the -ListenBacklog directive. Once a child process is freed at the -end of a different request, the connection will then be serviced. - -

MaxKeepAliveRequests directive

0", unlimited requests will be allowed. We recommend that this setting be kept to a high value for maximum server performance.

MaxRequestsPerChild directive

- -Syntax: MaxRequestsPerChild number
-Default: MaxRequestsPerChild 0
-Context: server config
-Status: core
-Compatibility: Moved in version 2.0 to the -MPMs.

- -The MaxRequestsPerChild directive sets the limit on the number of requests -that an individual child server process will handle. After MaxRequestsPerChild -requests, the child process will die. If MaxRequestsPerChild is 0, then -the process will never expire.

- -Setting MaxRequestsPerChild to a non-zero limit has two beneficial effects: -

it limits the amount of memory that process can consume by (accidental) -memory leakage; -
by giving processes a finite lifetime, it helps reduce the -number of processes when the server load reduces. -

- -

This directive has no effect on Win32. - -

NOTE: For KeepAlive requests, only the first -request is counted towards this limit. In effect, it changes the -behavior to limit the number of connections per child. - -

- -

MaxSpareServers directive

- -Syntax: MaxSpareServers number
-Default: MaxSpareServers 10
-Context: server config
-Status: core
-Compatibility: Moved in version 2.0 to the -MPMs.

- -The MaxSpareServers directive sets the desired maximum number of idle -child server processes. An idle process is one which is not handling -a request. If there are more than MaxSpareServers idle, then the parent -process will kill off the excess processes.

- -Tuning of this parameter should only be necessary on very busy sites. -Setting this parameter to a large number is almost always a bad idea.

- -This directive has no effect when used with the Apache Web server on a -Microsoft Windows platform. - -

- -See also MinSpareServers and -StartServers.

- -

MinSpareServers directive

- -Syntax: MinSpareServers number
-Default: MinSpareServers 5
-Context: server config
-Status: core
-Compatibility: Moved in version 2.0 to the -MPMs.

- -The MinSpareServers directive sets the desired minimum number of idle -child server processes. An idle process is one which is not handling -a request. If there are fewer than MinSpareServers idle, then the parent -process creates new children at a maximum rate of 1 per second.

- -Tuning of this parameter should only be necessary on very busy sites. -Setting this parameter to a large number is almost always a bad idea.

- -This directive has no effect on Microsoft Windows. - -

- -See also MaxSpareServers and -StartServers.

NameVirtualHost directive

The default in the absence of any other settings is All.

PidFile directive

- -Syntax: PidFile filename
-Default: PidFile logs/httpd.pid
-Context: server config
-Status: core
-Compatibility: Removed in version 2.0.

- -The PidFile directive sets the file to which the server records the -process id of the daemon. If the filename does not begin with a slash (/) -then it is assumed to be relative to the ServerRoot. -The PidFile is only used in standalone mode.

-It is often useful to be able to send the server a signal, so that it closes -and then reopens its ErrorLog and TransferLog, and -re-reads its configuration files. This is done by sending a SIGHUP (kill -1) -signal to the process id listed in the PidFile.

- -The PidFile is subject to the same warnings about log file placement and -security. - -

Port directive

@@ -2715,63 +2441,6 @@ See also Require and

ScoreBoardFile directive

- -Syntax: ScoreBoardFile filename
-Default: ScoreBoardFile logs/apache_status -
-Context: server config
-Status: core
-Compatibility: Moved in version 2.0 to the -MPMs.

- -The ScoreBoardFile directive is required on some architectures to place -a file that the server will use to communicate between its children and -the parent. The easiest way to find out if your architecture requires -a scoreboard file is to run Apache and see if it creates the file named -by the directive. If your architecture requires it then you must ensure -that this file is not used at the same time by more than one invocation -of Apache.

- -If you have to 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.

- -Apache 1.2 and above:

- -Linux 1.x users might be able to add --DHAVE_SHMGET -DUSE_SHMGET_SCOREBOARD to -the EXTRA_CFLAGS in your Configuration. This -might work with some 1.x installations, but won't work with all of -them. (Prior to 1.3b4, HAVE_SHMGET would have sufficed.)

- -SVR4 users should consider adding --DHAVE_SHMGET -DUSE_SHMGET_SCOREBOARD to the -EXTRA_CFLAGS in your Configuration. This -is believed to work, but we were unable to test it in time for 1.2 -release. (Prior to 1.3b4, HAVE_SHMGET would have sufficed.)

- -See Also: -Stopping and Restarting Apache

- -

ScriptInterpreterSource directive

StartServers directive

- -Syntax: StartServers number
-Default: StartServers 5
-Context: server config
-Status: core
-Compatibility: Moved in version 2.0 to the -MPMs.

- -The StartServers directive sets the number of child server processes created -on startup. As the number of processes is dynamically controlled depending -on the load, there is usually little reason to adjust this parameter.

- -

When running under Microsoft Windows, this directive has no effect. - There is always one child which handles all requests. Within the - child requests are handled by separate threads. The - ThreadsPerChild directive controls - the maximum number of child threads handling requests, which will - have a similar effect to the setting of StartServers - on Unix. - -

- -See also MinSpareServers and -MaxSpareServers.

- -

ThreadsPerChild

-Syntax: ThreadsPerChild number
-Default: ThreadsPerChild 50
-Context: server config
-Status: core (Windows, NetWare)
-Compatibility: Available only with Apache 1.3 and later -with Windows. Moved in version 2.0 to the MPMs. - -

This directive tells the server how many threads it should use. This - is the maximum number of connections the server can handle at once; be - sure and set this number high enough for your site if you get a lot of - hits. - -

This directive has no effect on Unix systems. Unix users should look - at StartServers and MaxRequestsPerChild.

- -

ThreadStackSize

CookieLog (mod_cookies)

CookieLog (mod_log_config)

Dav

DavDepthInfinity @@ -152,25 +152,25 @@ of the terms used in their descriptions available.

MaxKeepAliveRequests -

MaxRequestsPerChild -

MaxSpareServers +

MaxRequestsPerChild +

MetaDir

NoCache

Options

Order

PassEnv -

PidFile +

PidFile

Port

ProxyBlock

ProxyDomain @@ -203,7 +203,7 @@ of the terms used in their descriptions available.

Satisfy -

Script

ScriptAliasMatch @@ -224,8 +224,8 @@ of the terms used in their descriptions available.

TimeOut

TypesConfig diff --git a/docs/manual/mod/index.html b/docs/manual/mod/index.html index 2e831bdac9..81f79d7d75 100644 --- a/docs/manual/mod/index.html +++ b/docs/manual/mod/index.html @@ -24,9 +24,19 @@ directives.

Core Features and Multi-Processing Modules

Core: Core Apache features. +
mpmt_pthread +: Multi-Processing Model with Threading via Pthreads; Variable number +of processes, constant number of threads/child +

+ +

Other Modules

+ +

mod_access: Access control based on client hostname or IP address.
mod_actions diff --git a/docs/manual/mod/mpmt_pthread.html b/docs/manual/mod/mpmt_pthread.html new file mode 100644 index 0000000000..da3e8241d9 --- /dev/null +++ b/docs/manual/mod/mpmt_pthread.html @@ -0,0 +1,434 @@ + + + +Apache MPM mpmt_pthread + + + + + + +
Mulit-Processing Module mpmt_pthread
+
+This Multi-Processing Module controls process and thread creation +using the pthread interface. +
+ +
Status: MPM +
+Source File: mpmt_pthread.c +
+Module Identifier: mpm_mpmt_pthread_module +
+ +
Summary
+ +
This Multi-Processing Module (MPM) is the default for most unix-like +operating systems. It uses pthread system calls to create a hybrid +multi-process multi-threaded server. Each process has a fixed number +of threads. The server adjusts to handle load by increasing or +decreasing the number of processes.
+ + +
Directives
+
+
CoreDumpDirectory
+
PidFile
+
LockFile
+
MaxClients
+
MaxRequestsPerChild
+
MaxSpareThreads
+
MinSpareThreads
+
ScoreBoardFile
+
StartServers
+
ThreadsPerChild
+
+
+ +
CoreDumpDirectory directive
+ +
Syntax: CoreDumpDirectory directory
+Default: the same location as ServerRoot
+Context: server config
+Status: Base
+Module: mpmt_pthread
+ +
This controls the directory to which Apache attempts to switch +before dumping core. The default is in the ServerRoot directory, however since +this should not be writable by the user the server runs as, core dumps +won't normally get written. If you want a core dump for debugging, +you can use this directive to place it in a different location.
+ +
PidFile directive
+ +
Syntax: PidFile filename
+Default: PidFile logs/httpd.pid
+Context: server config
+Status: Base
+Module: mpmt_pthread
+ +
The PidFile directive sets the file to which the server records the +process id of the daemon. If the filename does not begin with a slash +(/) then it is assumed to be relative to the ServerRoot.
+ +
It is often useful to be able to send the server a signal, so that +it closes and then reopens its ErrorLog and TransferLog, and re-reads +its configuration files. This is done by sending a SIGHUP (kill -1) +signal to the process id listed in the PidFile.
+ +
The PidFile is subject to the same warnings about log file placement and +security.
+ + +
+ + +
LockFile directive
+
Syntax: LockFile filename
+Default: LockFile logs/accept.lock
+Context: server config
+Status: Base
+Module: mpmt_pthread
+ +
The LockFile directive sets the path to the lockfile used when +Apache is compiled with either USE_FCNTL_SERIALIZED_ACCEPT or +USE_FLOCK_SERIALIZED_ACCEPT. This directive should normally be +left at its default value. The main reason for changing it is if +the logs directory is NFS mounted, since the lockfile +must be stored on a local disk. The PID of the main +server process is automatically appended to the filename.
+ +
SECURITY: It is best to avoid putting this file in a +world writable directory such as /var/tmp because someone +could create a denial of service attack and prevent the server from +starting by creating a lockfile with the same name as the one the +server will try to create.
+ +
+ +
MaxClients directive
+ +
Syntax: MaxClients number
+Default: MaxClients 8 (with threads) +MaxClients 256 (no threads)
+Context: server config
+Status: core
+Module: mpmt_pthread
+ +
The MaxClients directive sets the limit on the number of child +processes that will be created to serve requests. When the server is +built without threading, no more than this number of clients can be +served simultaneously. To configure more than 256 clients, you must +edit the HARD_SERVER_LIMIT entry in +mpm_default.h and recompile. + +
Any connection attempts over the MaxClients limit will normally +be queued, up to a number based on the +ListenBacklog directive. Once a child process is freed at the +end of a different request, the connection will then be serviced.
+ +
When the server is compiled with threading, then the maximum number +of simultaneous requests that can be served is obtained from the value +of this directive multiplied by ThreadsPerChild.
+ +
+ +
MaxRequestsPerChild directive
+ +
Syntax: MaxRequestsPerChild number
+Default: MaxRequestsPerChild 10000
+Context: server config
+Status: core
+Module: mpmt_pthread
+ +
The MaxRequestsPerChild directive sets the limit on the number of requests +that an individual child server process will handle. After MaxRequestsPerChild +requests, the child process will die. If MaxRequestsPerChild is 0, then +the process will never expire.
+ +Setting MaxRequestsPerChild to a non-zero limit has two beneficial effects: +
+
it limits the amount of memory that process can consume by (accidental) +memory leakage; +
by giving processes a finite lifetime, it helps reduce the +number of processes when the server load reduces. +
+ +
NOTE: For KeepAlive requests, only the first +request is counted towards this limit. In effect, it changes the +behavior to limit the number of connections per child. + +
+ + +
MaxSpareThreads directive
+ +
Syntax: MaxSpareThreads number
+Default: MaxSpareThreads ??
+Context: server config
+Status: core
+Module: mpmt_pthread
+ +
Content needed here!
+ +
See also MinSpareThreads and +StartServers. + +
+ +
MinSpareThreads directive
+ +
Syntax: MinSpareServers number
+Default: MinSpareServers ???
+Context: server config
+Status: core
+Module: mpmt_pthread
+ +
fix me
+ +
The MinSpareServers directive sets the desired minimum number of idle +child server processes. An idle process is one which is not handling +a request. If there are fewer than MinSpareServers idle, then the parent +process creates new children at a maximum rate of 1 per second.
+ +Tuning of this parameter should only be necessary on very busy sites. +Setting this parameter to a large number is almost always a bad idea.
+ +This directive has no effect on Microsoft Windows. + +
+ +See also MaxSpareThreads and +StartServers.
+ + +
ScoreBoardFile directive
+ +
Syntax: ScoreBoardFile filename
+Default: ScoreBoardFile logs/apache_status +
+Context: server config
+Status: Base
+ +Module: mpmt_pthread
+ +
The ScoreBoardFile directive is required on some architectures to place +a file that the server will use to communicate between its children and +the parent. The easiest way to find out if your architecture requires +a scoreboard file is to run Apache and see if it creates the file named +by the directive. If your architecture requires it then you must ensure +that this file is not used at the same time by more than one invocation +of Apache.
+ +
If you have to 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.
+ +
See Also: +Stopping and Restarting Apache
+ + +
+ +
StartServers directive
+ +
Syntax: StartServers number
+Default: StartServers 5
+Context: server config
+Status: core
+Module: mpmt_pthread
+ +
The StartServers directive sets the number of child server processes created +on startup. As the number of processes is dynamically controlled depending +on the load, there is usually little reason to adjust this parameter.
+ +
See also MinSpareThreads and +MaxSpareThreads.
+ +
ThreadsPerChild
+
Syntax: ThreadsPerChild number
+Default: ThreadsPerChild 50
+Context: server config
+Status: Base
+Module: mpmt_pthread
+ +
This directive sets the number of threads created by each child +process.
+ + + + + -- 2.50.1

Core Features and Multi-Processing Modules

Other Modules

Mulit-Processing Module mpmt_pthread

Summary

Directives