Merge r1770771 from trunk:

Describe new behavior of ServerLimit

This has changed a bit after the fix for PR 53555. Better wording is welcome.

Submitted by: sf
Reviewed/backported by: jim

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/branches/2.4.x@1772336 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/docs/manual/mod/mpm_common.xml b/docs/manual/mod/mpm_common.xml
index 08e7def271058984e1f5b51b3a46042007af738f..1da81bcd5e3b908981e1dcef07fe716f9232594b 100644 (file)
--- a/docs/manual/mod/mpm_common.xml
+++ b/docs/manual/mod/mpm_common.xml
@@ -617,10 +617,12 @@ Apache HTTP Server</a></seealso>
     module="mpm_common">ThreadLimit</directive> sets
     the maximum configured value for <directive
     module="mpm_common">MaxRequestWorkers</directive> for the lifetime of the
-    Apache httpd process. Any attempts to change this directive during a
-    restart will be ignored, but <directive
-    module="mpm_common">MaxRequestWorkers</directive> can be modified during
-    a restart.</p>
+    Apache httpd process. For the <module>event</module> MPM, this directive
+    also defines how many old server processes may keep running and finish processing
+    open connections.
+    Any attempts to change this directive during a restart will be ignored, but
+    <directive module="mpm_common">MaxRequestWorkers</directive> can be modified
+    during a restart.</p>
 
     <p>Special care must be taken when using this directive.  If
     <directive>ServerLimit</directive> is set to a value much higher
@@ -637,8 +639,8 @@ Apache HTTP Server</a></seealso>
     might want to set <directive
     module="mpm_common">MaxRequestWorkers</directive> to.</p>
 
-    <p>With <module>worker</module> and <module>event</module>, use this
-    directive only if your <directive module="mpm_common">MaxRequestWorkers
+    <p>With <module>worker</module>, use this directive only if your
+    <directive module="mpm_common">MaxRequestWorkers
     </directive> and <directive module="mpm_common">ThreadsPerChild</directive>
     settings require more than 16 server processes (default). Do not set
     the value of this directive any higher than the number of server
@@ -646,6 +648,13 @@ Apache HTTP Server</a></seealso>
     module="mpm_common">MaxRequestWorkers </directive> and <directive
     module="mpm_common">ThreadsPerChild</directive>.</p>
 
+    <p>With <module>event</module>, increase this directive if the process
+    number defined by your <directive
+    module="mpm_common">MaxRequestWorkers</directive> and <directive
+    module="mpm_common">ThreadsPerChild</directive> settings, plus the
+    number of gracefully shutting down processes, is more than 16 server
+    processes (default).</p>
+
     <note><title>Note</title>
       <p>There is a hard limit of <code>ServerLimit 20000</code> compiled
       into the server (for the <module>prefork</module> MPM 200000). This is