Have people use sysctl to adjust somaxconn

instead of the bogus and incorrect method we suggested before


git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@81412 13f79535-47bb-0310-9956-ffa450edef68

docs/manual/platform/perf-bsd44.html

@@ -112,7 +112,6 @@ your own values in the kernel configuration file:
 # Network options. NMBCLUSTERS defines the number of mbuf clusters and
 # defaults to 256. This machine is a server that handles lots of traffic,
 # so we crank that value.
-options         SOMAXCONN=256           # max pending connects
 options         NMBCLUSTERS=4096        # mbuf clusters at 4096
 
 #
@@ -122,10 +121,6 @@ options         CHILD_MAX=512           # maximum number of child processes
 options         OPEN_MAX=512            # maximum fds (breaks RPC svcs)
 </PRE>
 
-SOMAXCONN is not derived from maxusers, so you'll always need to increase
-that yourself. We used a value guaranteed to be larger than Apache's
-default for the listen() of 128, currently.
-
 <P>
 
 In many cases, NMBCLUSTERS must be set much larger than would appear
@@ -163,6 +158,27 @@ value derived from maxusers proved sufficient for our load.
 
 <P>
 
+To increase the size of the <CODE>listen()</CODE> queue, you need to
+adjust the value of SOMAXCONN. SOMAXCONN is not derived from maxusers,
+so you'll always need to increase that yourself. We use a value guaranteed
+to be larger than Apache's default for the listen() of 128, currently.
+The actual value for SOMAXCONN is set in <CODE>sys/socket.h</CODE>.
+The best way to adjust this parameter is run-time, rather than changing
+it in this header file and thus hardcoding a value in the kernel and
+elsewhere.  To do this, edit <CODE>/etc/rc.local</CODE> and add the
+following line:
+<PRE>
+    /usr/sbin/sysctl -w kern.somaxconn=256
+</PRE>
+
+<P>
+
+We used <CODE>256</CODE> but you can tune it for your own setup. In
+many cases, however, even the default value of <CODE>128</CODE> (for
+later versions of FreeBSD) is OK.
+
+<P>
+
 <STRONG>Caveats</STRONG>
 
 <P>