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Posted to cvs@httpd.apache.org by tr...@apache.org on 2009/09/26 15:02:45 UTC
svn commit: r819129 - /httpd/mod_fcgid/trunk/docs/manual/mod/mod_fcgid.xml
Author: trawick
Date: Sat Sep 26 13:02:45 2009
New Revision: 819129
URL: http://svn.apache.org/viewvc?rev=819129&view=rev
Log:
rework the spawn rate documentation
provide a list of concept->directive mappings in the process management overview
Modified:
httpd/mod_fcgid/trunk/docs/manual/mod/mod_fcgid.xml
Modified: httpd/mod_fcgid/trunk/docs/manual/mod/mod_fcgid.xml
URL: http://svn.apache.org/viewvc/httpd/mod_fcgid/trunk/docs/manual/mod/mod_fcgid.xml?rev=819129&r1=819128&r2=819129&view=diff
==============================================================================
--- httpd/mod_fcgid/trunk/docs/manual/mod/mod_fcgid.xml (original)
+++ httpd/mod_fcgid/trunk/docs/manual/mod/mod_fcgid.xml Sat Sep 26 13:02:45 2009
@@ -345,7 +345,44 @@
<section id="process-mgmt">
<title>Process Management</title>
- <p>TODO</p>
+ <p>mod_fcgid has several types of controls which affect the creation
+ of additional application processes:</p>
+
+ <table border="1" style="zebra">
+ <tr><th>Type of control</th><th>Directive</th></tr>
+ <tr>
+ <td>global limit on number of processes</td>
+ <td><directive module="mod_fcgid">FCGIDMaxProcessCount</directive></td>
+ </tr>
+ <tr>
+ <td>limit on number of processes per application</td>
+ <td><directive module="mod_fcgid">FCGIDMaxClassProcessCount</directive></td>
+ </tr>
+ <tr>
+ <td>limit on rate of spawning new application processes</td>
+ <td><directive module="mod_fcgid">FCGIDSpawnScoreUpLimit</directive> and
+ other score-related directives</td>
+ </tr>
+ </table>
+
+ <p>mod_fcgid has several types of controls which affect the termination
+ of existing application processes:</p>
+
+ <table border="1" style="zebra">
+ <tr><th>Type of control</th><th>Directive</th></tr>
+ <tr>
+ <td>termination after an idle period</td>
+ <td><directive module="mod_fcgid">FCGIDIdleTimeout</directive></td>
+ </tr>
+ <tr>
+ <td>termination after it handles a certain number of requests</td>
+ <td><directive module="mod_fcgid">FCGIDMaxRequestsPerProcess</directive></td>
+ </tr>
+ <tr>
+ <td>termination after a certain lifetime</td>
+ <td><directive module="mod_fcgid">FCGIDProcessLifetime</directive></td>
+ </tr>
+ </table>
<note type="hint"><title>Note</title>
<p>Certain settings or other concepts that depend on the virtual host,
@@ -856,6 +893,8 @@
<default>FCGIDSpawnScore 1</default>
<contextlist><context>server config</context></contextlist>
<usage>
+ <p>Lower values of this directive increase the allowed spawn rate.</p>
+
<p>Refer to the <directive module="mod_fcgid">FCGIDSpawnScoreUpLimit</directive>
directive for more information.</p>
</usage>
@@ -869,19 +908,30 @@
<default>FCGIDSpawnScoreUpLimit 10</default>
<contextlist><context>server config</context></contextlist>
<usage>
- <p>The module maintains a process activity score for each FastCGI
- application which represents process activity; it uses that score to
- determine if more instances of the FastCGI application can be spawned
- (started). If the current score is higher than the value of this
- directive, a new instance of the FastCGI application cannot yet be
- started.</p>
-
- <p>The <directive module="mod_fcgid">FCGIDSpawnScore</directive> directive
- determines how much is added to the score for every spawned application
- process. The <directive module="mod_fcgid">FCGIDTerminationScore</directive>
- directive determines how much is added to the score for every terminated
- application process. The <directive module="mod_fcgid">FCGIDTimeScore</directive>
- directive determines how much is subtracted from the score every second.</p>
+ <p>A process activity score is maintained for each FastCGI application;
+ the score is used to control the rate of spawning in order to avoid
+ placing too much load on the system, particularly for applications that
+ are repeatedly exiting abnormally.</p>
+
+ <p>The value of <directive module="mod_fcgid">FCGIDSpawnScore</directive>
+ is added to the score for every spawned application process. The value of
+ <directive module="mod_fcgid">FCGIDTerminationScore</directive> is added
+ to the score for every terminated application process. The value of
+ <directive module="mod_fcgid">FCGIDTimeScore</directive> is subtracted
+ from the score every second.</p>
+
+ <p>When the current score is higher than the value of
+ <directive>FCGIDSpawnScoreUpLimit</directive>, no additional application
+ processes will be spawned; subsequent requests must wait until an existing
+ process is free or until the score decreases below the limit.</p>
+
+ <p>If the limit is reached under normal load, it may not be sufficient to
+ simply increase the limit, as that would only delay the amount of time
+ before the limit is reached again. Decrease the value of
+ <directive module="mod_fcgid">FCGIDSpawnScore</directive> and/or
+ <directive module="mod_fcgid">FCGIDTerminationScore</directive>, or
+ increase the value of <directive module="mod_fcgid">FCGIDTimeScore</directive>,
+ to allow a higher rate of spawning.</p>
</usage>
</directivesynopsis>
@@ -893,6 +943,10 @@
<default>FCGIDTerminationScore 2</default>
<contextlist><context>server config</context></contextlist>
<usage>
+ <p>Lower values of this directive increase the allowed spawn rate. Negative
+ values can be useful in some circumstances, such as allowing process
+ replacement without increasing the score.</p>
+
<p>Refer to the <directive module="mod_fcgid">FCGIDSpawnScoreUpLimit</directive>
directive for more information.</p>
</usage>
@@ -906,6 +960,8 @@
<default>FCGIDTimeScore 1</default>
<contextlist><context>server config</context></contextlist>
<usage>
+ <p>Higher values of this directive increase the allowed spawn rate.</p>
+
<p>Refer to the <directive module="mod_fcgid">FCGIDSpawnScoreUpLimit</directive>
directive for more information.</p>
</usage>