Changeset 1203

Timestamp:

06/16/08 22:26:07 (2 years ago)

Author:

ahu

Message:

update documentation so it now mentions 1) the geo backend 2) the exact conditions needed to benefit from supermaster notifications

Files:

• trunk/pdns/pdns/docs/pdns.sgml (modified) (6 diffs)

trunk/pdns/pdns/docs/pdns.sgml

@@ -8234 +8234 @@
   if qtype ~= pdns.A then return -1, ret end  --  only A records
   if not string.find(domain, "^www.") then return -1, ret end  -- only things that start with www.
-  if not matchnetmask(ip, "10.0.0.0/8")  then return -1, ret end -- only interfere with local queries
+  if not matchnetmask(ip, "10.0.0.0/8", "192.168.0.0/16")  then return -1, ret end -- only interfere with local queries
   ret[1]={qtype=pdns.A, content="127.1.2.3"}    -- add IN A 127.1.2.3
   ret[2]={qtype=pdns.A, content="127.3.2.1"}    -- add IN A 127.3.2.1
@@ -8319 +8319 @@
             </para>
           </warning>
+        </para>
+        <para>
+          Finally, the function <function>matchnetmask(ip, netmask1, netmask2..)</function> is available to match incoming queries against
+          a number of netmasks. If any of these matches, the function returns true.
         </para>
       </sect2>
@@ -8635 +8639 @@
         multiple masters, for SQL based backends, list all master servers separated by commas in the 'master' field of the domains table.
       </para>
-      <sect2 id=supermaster><title>Supermaster automatic provisioning of slaves</title>
+      <sect2 id="supermaster"><title>Supermaster automatic provisioning of slaves</title>
         <para>
           PDNS can recognize so called 'supermasters'. A supermaster is a host which is master for domains and for which we are to be a slave. When
@@ -8646 +8650 @@
         </para>
         <para>
-          To enable this feature, a backend needs to know about the IP address of the supermaster, and how PDNS will be listed in the set of
-          NS records remotely, and the 'account' name of your supermaster. There is no need to fill this out but it does help keep track of
+          Before a supermaster notification succeeds, the following conditions must be met:
+          <itemizedlist>
+            <listitem><para>
+                The supermaster must carry a SOA record for the notified domain
+            </para></listitem>
+            <listitem><para>
+                The supermaster IP must be present in the 'supermaster' table
+            </para></listitem>
+            <listitem><para>
+                The set of NS records for the domain, as retrieved by the slave from the supermaster, must include the name that 
+                goes with the IP address in the supermaster table
+            </para></listitem>
+          </itemizedlist>
+        </para>
+        <para>
+          So, to benefit from this feature, a backend needs to know about the IP address of the supermaster, and how PDNS will be listed in the set of
+          NS records remotely, and the 'account' name of your supermaster. There is no need to fill the account name out but it does help keep track of
           where a domain comes from.
         </para>
@@ -11967 +11986 @@
     <sect1 id="xdbbackend"><Title>XDB Backend</title>
       <para>
-        Special purpose backend for grandiose performance. Can talk to Tridge's Trivial Database, or to regular *db tables on disk. Currently only sparsely
-        documented. Very useful if you need to do &gt;50.000 queries/second, which we actually measured on the .ORG zone.
-      </para>
-      <para>
-        More documentation will follow.
+        No longer part of PowerDNS.
       </para>
     </sect1>
@@ -12033 +12048 @@
       </para>
     </sect1>
+    <sect1 id="geo"><Title>Geo backend</title>
+      <para>
+        <warning>
+          <para>
+            This section is a subset of the full documentation which can be found in <filename>modules/geobackend/README</filename> of
+            the PowerDNS distribution.
+          </para>
+        </warning>
+      </para>
+      <para>
+        The main author for this module is Mark Bergsma.
+      </para>
+      <para>
+        <table>
+          <title>Geo backend capabilities</title>
+          <tgroup cols=2>
+            <tbody>
+              <row><entry>Native</entry><entry>Partial</entry></row>
+              <row><entry>Master</entry><entry>No</entry></row>
+              <row><entry>Slave</entry><entry>No</entry></row>
+              <row><entry>Superslave</entry><entry>No</entry></row>
+              <row><entry>Autoserial</entry><entry>No</entry></row>
+            </tbody>
+          </tgroup>
+        </table>
+      </para>
+      <para>
+        The Geo Backend can be used to distribute queries globally using an IP-address/country mapping table, several of which are freely available
+        online or can be acquired for a small fee.
+      </para>
+      <para>
+        This allows visitors to be sent to a server close to them, with no appreciable delay, as would otherwise be incurred with a protocol level redirect.
+        Additionally, the Geo Backend can be used to provide service over several clusters, any of which can be taken out of use easily, for example 
+        for maintenance purposes.
+      </para>
+      <para>
+        The Geo Backend is in wide use, for example by the Wikimedia foundation, which uses it to power the Wikipedia global load balancing.
+      </para>
+      <para>
+        More details can be found <ulink url="http://wiki.powerdns.com/cgi-bin/trac.fcgi/browser/trunk/pdns/modules/geobackend/README">here</ulink>, or in
+        <filename>modules/geobackend/README</filename>, part of the PowerDNS Authoritative Server distribution.
+      </para>
+    </sect1>
+
   </appendix>
 <appendix id="pdns-internals"><title>PDNS internals</title>