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    <tt>Hi Andreas,<br>
         NDB requires a minimum of 4 nodes for HA... 2x SQL/mgmnt nodes
      + 2x data nodes.  The SQL/mgmnt nodes could be your tomcat servers
      without problem but the data nodes must be other physical servers.<br>
      <br>
      Regards,<br>
      <br>
      Yves<br>
    </tt><br>
    On 12-01-30 04:46 AM, Stallmann, Andreas wrote:
    <blockquote
cite="mid:EE56AE15B0E72547AF6357C10663B9D712607F53@SHE9EXM502.corp.conet.local"
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        <p class="MsoNormal"><span lang="EN-US">Hi!<o:p></o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US">I’m on the lookout for
            alternatives to our current MySQL “cluster”, which is an
            Active/Standby solution with MySQL on DRBD.<o:p></o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US">With increasing customer
            demand for a faster failover, we want an Active/Passive or
            even an Active/Active cluster.<o:p></o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US">Currently we run a
            Tomcat application, which works in Active/Passive-Mode. The
            applications on the active node communicate it’s status via
            a MySQL database to the passive node. In our current setup,
            both nodes run the tomcat application but only one holds the
            database (due to the setup with DRBD). For faster failovers,
            we’d rather want the database to be active on both nodes.
            It’s not necessary, that it can written on both nodes, but
            read access would be desirable. The thought is, that
            switching the “master status” of a database might be quicker
            than switching DRBD’s master status, unmounting and mounting
            the file system and stopping and starting the database.
            <o:p></o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US">A MySQL/Pacemaker
            cluster with replication as described  in
            <a moz-do-not-send="true"
href="http://www.mysqlperformanceblog.com/2011/11/29/percona-replication-manager-a-solution-for-mysql-high-availability-with-replication-using-pacemaker/">http://www.mysqlperformanceblog.com/2011/11/29/percona-replication-manager-a-solution-for-mysql-high-availability-with-replication-using-pacemaker/</a>
             thus looked very promising, but it seems to be not yet
            mature enough for a production environment. Please do
            correct men if I’m wrong there, I’m really interested in
            your experience with this solution in a real world scenario.
            <o:p></o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US">Are there perhaps other
            howtos describing Pacemaker and MySQL replication?<o:p></o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US">The second idea was
            using the native MySQL NDB clustering with Pacemaker.
            <a moz-do-not-send="true"
href="http://www.mysqlperformanceblog.com/2010/05/19/pacemaker-please-meet-ndb-cluster-or-using-pacemakerheartbeat-to-start-a-ndb-cluster/">http://www.mysqlperformanceblog.com/2010/05/19/pacemaker-please-meet-ndb-cluster-or-using-pacemakerheartbeat-to-start-a-ndb-cluster/</a>
            (from 2010, uses heartbeat and pacemaker) and
            <a moz-do-not-send="true"
              href="http://www.howtoforge.com/loadbalanced_mysql_cluster_debian">http://www.howtoforge.com/loadbalanced_mysql_cluster_debian</a>
            (from 2008, uses pure heartbeat). Are there any more recent
            “howtos” on pacemaker and MySQL NDB 7.x describe this. Can
            you provide me with your opinions and field reports on these
            setups?<o:p></o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US">Looking forward to your
            upcoming mails,<o:p></o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US">Andreas<o:p></o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
        <p class="MsoNormal"><span lang="EN-US"><o:p> </o:p></span></p>
      </div>
      <p class="abd03441-7d3a-47dc-ab5f-8a54a3cc2c8d"> </p>
      <p class="abd03441-7d3a-47dc-ab5f-8a54a3cc2c8d">----------------------------<br>
        CONET Solutions GmbH, Theodor-Heuss-Allee 19, 53773 Hennef.<br>
        Registergericht/Registration Court: Amtsgericht Siegburg (HRB
        Nr. 9136)<br>
        Geschäftsführer/Managing Director: Anke Höfer </p>
      <p class="abd03441-7d3a-47dc-ab5f-8a54a3cc2c8d"> ----------------------------</p>
      <p class="abd03441-7d3a-47dc-ab5f-8a54a3cc2c8d"> </p>
      <pre wrap="">
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_______________________________________________
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Project Home: <a class="moz-txt-link-freetext" href="http://www.clusterlabs.org">http://www.clusterlabs.org</a>
Getting started: <a class="moz-txt-link-freetext" href="http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf">http://www.clusterlabs.org/doc/Cluster_from_Scratch.pdf</a>
Bugs: <a class="moz-txt-link-freetext" href="http://bugs.clusterlabs.org">http://bugs.clusterlabs.org</a>
</pre>
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