add dnsdist manpage!

ahupowerdns · ahupowerdns · commit 3e4a8caf9480 · 2013-06-28T17:05:37.000+02:00
diff --git a/pdns/dnsdist.cc b/pdns/dnsdist.cc
@@ -331,7 +331,7 @@ void* tcpClientThread(void* p)
 	ds->outstanding++;
 	char query[qlen];
 	readn2(ci.fd, query, qlen);
-	
+	// FIXME: drop AXFR queries here, they confuse us
       retry:; 
 	if(!putMsgLen(dsock, qlen)) {
 	  infolog("Downstream connection to %s died on us, getting a new one!", ds->remote.toStringWithPort());
diff --git a/pdns/docs/dnsdist.1.txt b/pdns/docs/dnsdist.1.txt
@@ -0,0 +1,79 @@
+DNSDIST(1)
+==========
+powerdns.documentation@powerdns.com
+
+NAME
+----
+dnsdist - tool to balance DNS queries over downstream servers
+
+SYNOPSIS
+--------
+'dnsdist' [--help] [--verbose] [--local address] downstream-address downstream-address
+
+DESCRIPTION
+-----------
+dnsdist receives DNS queries and relays them to one or more downstream
+servers. It subsequently sends back responses to the original requestor.
+
+dnsdist operates over TCP and UDP, and strives to deliver very high
+performance over both.
+
+Currently, queries are sent to the downstream server with the least
+outstanding queries. This effectively implies load balancing, making sure
+that slower servers get less queries.
+
+If a reply has not come in after a few seconds, it is removed from the
+queue, but in the short term, timeouts do cause a server to get less
+traffic.
+
+IPv4 and IPv6 operation can be mixed and matched, in other words, queries
+coming in over IPv6 could be forwarded to IPv4 and vice versa.
+
+SCOPE
+-----
+dnsdist does not 'think' about DNS, and does not perform any kind of
+caching, nor is it aware of the quality of the answers it is relaying.
+
+dnsdist assumes that each query leads to exactly one response, which is true
+for all DNS except for AXFR, which is therefore not supported.
+
+The goal for dnsdist is to remain simple. If more powerful loadbalancing is
+required, dedicated hardware or software is recommended. Linux Virtual
+Server for example is often mentioned.
+
+OPTIONS
+-------
+
+--verbose::
+	Be wordy on what the program is doing
+
+--local::
+	Supply as many addresses to listen on as required. Specify IPv4 as
+	0.0.0.0:53 and IPv6 as [::]:53.
+
+--daemon::
+	Daemonize and run in the background
+
+--help::
+	Provide a helpful message
+
+Finally, supply as many downstream addresses as required. Remote port defaults to 53.
+
+BUGS
+----
+Right now, the TCP support has some rather arbitrary limits. 
+
+AUTHOR
+------
+Written by PowerDNS.COM BV, powerdns.documentation@powerdns.com
+
+RESOURCES
+---------
+Website: http://www.powerdns.com
+
+COPYING
+-------
+Copyright (C) 2013 PowerDNS.COM BV. Free use of this software
+is granted under the terms of the GNU General Public License (GPL) version
+2.
+
