svn commit - mysqldoc@docsrva: r11372 - trunk/refman-5.1

[jon]

Author: jstephens
Date: 2008-07-25 07:40:13 +0200 (Fri, 25 Jul 2008)
New Revision: 11372

Log:

Committing recent work on WL#4453 (NDB/Multi-master replication)

(Commented out for now.)



Modified:
   trunk/refman-5.1/mysql-cluster-limitations.xml
   trunk/refman-5.1/mysql-cluster-replication.xml


Modified: trunk/refman-5.1/mysql-cluster-limitations.xml
===================================================================
--- trunk/refman-5.1/mysql-cluster-limitations.xml	2008-07-25 03:44:12 UTC (rev 11371)
+++ trunk/refman-5.1/mysql-cluster-limitations.xml	2008-07-25 05:40:13 UTC (rev 11372)
Changed blocks: 2, Lines Added: 9, Lines Deleted: 0; 927 bytes

@@ -1628,6 +1628,11 @@
 
           </formalpara>
 
+          <remark role="TODO">
+            [js] WL#4453: Change xref in following when publishing new
+            mysql-cluster-replication-multi-master section
+          </remark>
+
           <formalpara>
 
             <title>Circular Replication</title>

@@ -1636,6 +1641,10 @@
               Circular replication is supported for MySQL Cluster
               beginning with MySQL 5.1.18. See
               <xref linkend="mysql-cluster-replication-issues"/>.
+
+<!-- 
+              <xref linkend="mysql-cluster-replication-multi-master"/>. 
+-->
             </para>
 
           </formalpara>


Modified: trunk/refman-5.1/mysql-cluster-replication.xml
===================================================================
--- trunk/refman-5.1/mysql-cluster-replication.xml	2008-07-25 03:44:12 UTC (rev 11371)
+++ trunk/refman-5.1/mysql-cluster-replication.xml	2008-07-25 05:40:13 UTC (rev 11372)
Changed blocks: 3, Lines Added: 183, Lines Deleted: 1; 7132 bytes

@@ -344,6 +344,11 @@
       </listitem>
 
       <listitem>
+        <remark role="TODO">
+          [js] WL#4453: Remove this listitem when publishing new
+          mysql-cluster-replication-multi-master section
+        </remark>
+
         <formalpara>
 
           <title>Circular replication</title>

@@ -2397,7 +2402,7 @@
       or die "Prepare to CHANGE MASTER error: ", $dbhS-&gt;errstr;
 
   $sth-&gt;execute
-       or die "CHNAGE MASTER on slave error: ", $sth-&gt;errstr;
+       or die "CHANGE MASTER on slave error: ", $sth-&gt;errstr;
   $sth-&gt;finish;
   print "\tSlave has been updated. You may now start the slave.\n";
 }

@@ -2409,6 +2414,183 @@
 
   </section>
 
+<!--
+    <remark role="TODO">
+      [js] WL#4453: Uncomment this section
+    </remark>
+  
+    <section id="mysql-cluster-replication-multi-master">
+
+    <title>Multi-Master and Circular Replication</title>
+
+    <para>
+      Beginning with MySQL 5.1.18, it is possible to use MySQL Cluster
+      in multi-master replication, including circular replication
+      between a number of MySQL Clusters.
+    </para>
+
+    <note>
+      <para>
+        Prior to MySQL 5.1.18, multi-master replication including
+        circular replication was not supported with MySQL Cluster
+        replication. This was because log events created in a particular
+        MySQL Cluster were wrongly tagged with the server ID of the
+        master rather than the server ID of the originating server.
+      </para>
+    </note>
+
+    <formalpara>
+
+      <title>Circular replication example</title>
+
+      <para>
+        In the next few paragraphs we consider the example of a
+        replication setup involving three MySQL Clusters numbered 1, 2,
+        and 3, in which Cluster 1 acts as the replication master for
+        Cluster 2, Cluster 2 acts as the master for Cluster 3, and
+        Cluster 3 acts as the master for Cluster 1. Each cluster has two
+        SQL nodes, with SQL nodes A and B belonging to Cluster 1, SQL
+        nodes C and D belonging to Cluster 2, and SQL nodes E and F
+        belonging to Cluster 3.
+      </para>
+
+    </formalpara>
+
+    <para>
+      Circular replication using these clusters is supported as long as:
+
+      <itemizedlist>
+
+        <listitem>
+          <para>
+            The SQL nodes on all masters and slaves are the same
+          </para>
+        </listitem>
+
+        <listitem>
+          <para>
+            All SQL nodes acting as replication masters and slaves are
+            started using the <option>&ddash;log-slave-updates</option>
+            option
+          </para>
+        </listitem>
+
+      </itemizedlist>
+
+      This type of circular replication setup is shown in the following
+      diagram:
+
+      <mediaobject>
+        <imageobject>
+          <imagedata
fileref="../refman-common/images/published/cluster-circular-replication-1.png"
format="PNG"/>
+        </imageobject>
+        <textobject>
+          <phrase lang="en">Cluster circular replication scheme in which
+          all master SQL nodes are also slaves.</phrase>
+        </textobject>
+      </mediaobject>
+
+      In this scenario, SQL node A in Cluster 1 replicates to SQL node C
+      in Cluster 2; SQL node C replicates to SQL node E in Cluster 3;
+      SQL node E replicates to SQL node A. In other words, the
+      replication line (indicated by the red arrows in the diagram)
+      directly connects all SQL nodes used as replication masters and
+      slaves.
+    </para>
+
+    <para>
+      It should also be possible to set up circular replication in which
+      not all master SQL nodes are also slaves, as shown here:
+
+      <mediaobject>
+        <imageobject>
+          <imagedata
fileref="../refman-common/images/published/cluster-circular-replication-2.png"
format="PNG"/>
+        </imageobject>
+        <textobject>
+          <phrase lang="en">Cluster circular replication scheme in which
+          all master SQL nodes are not also necessarily slaves.</phrase>
+        </textobject>
+      </mediaobject>
+
+      In this case, different SQL nodes in each cluster are used as
+      replication masters and slaves. However, you must
+      <emphasis>not</emphasis> start any of the SQL nodes using
+      <option>&ddash;log-slave-updates</option> (see the
+      <link linkend="option_mysqld_log-slave-updates">description of
+      this option</link> for more information). This type of circular
+      replication scheme for MySQL Cluster, in which the line of
+      replication (again indicated by the red arrows in the diagram) is
+      discontinuous, should be possible, but it should be noted that it
+      has not yet been thoroughly tested and must therefore still be
+      considered experimental.
+    </para>
+
+    <important>
+      <para>
+        Beginning with MySQL 5.1.24, you should execute the following
+        statement before starting circular replication:
+
+<programlisting>
+mysql&gt; <userinput>SET GLOBAL SLAVE_EXEC_MODE =
'IDEMPOTENT';</userinput>
+</programlisting>
+
+        This is necessary to suppress duplicate-key and other errors
+        that otherwise break circular replication of MySQL Cluster.
+        <literal>IDEMPOTENT</literal> mode is also required for
+        multi-master replication when using MySQL Cluster. (Bug #31609)
+      </para>
+
+      <para>
+        See
+        <link
linkend="option_mysqld_slave_exec_mode"><literal>Slave_exec_mode</literal></link>,
+        for more information.
+      </para>
+    </important>
+
+    <formalpara>
+
+      <title>Multi-master failover example</title>
+
+      <para>
+        In this section, we discuss failing over in a multi-master MySQL Cluster
+        replication setup such as that shown here:
+
+        <mediaobject>
+          <imageobject>
+            <imagedata
fileref="../refman-common/images/published/cluster-replication-multi-master.png"
format="PNG"/>
+          </imageobject>
+          <textobject>
+            <phrase lang="EN">Multi-master MySQL Cluster replication
+            setup, with three MySQL Clusters</phrase>
+          </textobject>
+        </mediaobject>
+      </para>
+
+    </formalpara>
+
+    <para>
+      <mediaobject>
+        <imageobject>
+          <imagedata
fileref="../refman-common/images/published/cluster-replication-log-slave-updates.png"
format="PNG"/>
+        </imageobject>
+        <textobject>
+          <phrase lang="EN">Multi-master MySQL Cluster replication
+          setup, detail with MySQL Servers</phrase>
+        </textobject>
+      </mediaobject>
+    </para>
+
+    <note>
+      <para>
+        Replication slaves must be run with the
+        <option>&ddash;log-slave-updates</option> option. Using this
option
+        has no effect on servers not being run as replication slaves.
+      </para>
+    </note>
+
+  </section>
+-->
+
   <section id="mysql-cluster-replication-conflict-resolution">
 
     <title>MySQL Cluster Replication Conflict Resolution</title>