activemq-artemis

History
Martyn Taylor 150c5d87aa [maven-release-plugin] prepare release 1.2.0		2016-01-04 09:19:35 +00:00
..
src/main	Remove redundant type arguments	2015-12-07 22:55:05 +02:00
pom.xml	[maven-release-plugin] prepare release 1.2.0	2016-01-04 09:19:35 +00:00
readme.html	renaming broker-features -> features on examples	2015-08-13 00:11:56 -04:00
readme.html

<!--
Licensed to the Apache Software Foundation (ASF) under one
or more contributor license agreements.  See the NOTICE file
distributed with this work for additional information
regarding copyright ownership.  The ASF licenses this file
to you under the Apache License, Version 2.0 (the
"License"); you may not use this file except in compliance
with the License.  You may obtain a copy of the License at

  http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing,
software distributed under the License is distributed on an
"AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
KIND, either express or implied.  See the License for the
specific language governing permissions and limitations
under the License.
-->

<html>
  <head>
    <title>ActiveMQ Artemis JMS Colocated Failover Scale Down Example</title>
    <link rel="stylesheet" type="text/css" href="../../../common/common.css" />
    <link rel="stylesheet" type="text/css" href="../../../common/prettify.css" />
    <script type="text/javascript" src="../../../common/prettify.js"></script>
  </head>
  <body onload="prettyPrint()">
     <h1>JMS Colocated Failover Recover Only Example</h1>
     <pre>To run the example, simply type <b>mvn verify</b> from this directory. This example will always spawn and stop multiple servers.</pre>


     <p>This example demonstrates how you can colocate live and backup servers in the same VM. We do this by creating an
         HA Policy that is colocated. colocated means that backup servers can be created and maintained by live servers on behalf
         of other requesting live servers. In this example we create a colocated shared store server that will scale down.
         That is it will not become live but scale down the journal to the colocated live server.
     <p>This example starts 2 live servers each will request the other to create a backup.</p>
     <p>The first live server will be killed and the backup in the second will recover the journal and recreate its state
         in the live server it shares its VM with.</p>
     <p>The following shows how to configure the backup, the slave is configured <b>&lt;scale-down/></b> which means
         that the backup server will not fully start on fail over, instead it will just recover the journal and write it
     to its parent live server.</p>
     <pre class="prettyprint">
     <code>&lt;ha-policy>
         &lt;shared-store>
             &lt;colocated>
                 &lt;backup-port-offset>100&lt;/backup-port-offset>
                 &lt;backup-request-retries>-1&lt;/backup-request-retries>
                 &lt;backup-request-retry-interval>2000&lt;/backup-request-retry-interval>
                 &lt;max-backups>1&lt;/max-backups>
                 &lt;request-backup>true&lt;/request-backup>
                 &lt;master/>
                 &lt;slave>
                     &lt;scale-down/>
                 &lt;/slave>
             &lt;/colocated>
         &lt;/shared-store>
     &lt;/ha-policy>
     </code>
     </pre>
     <p>Notice that we dont need to specify a scale down connector as it will use most appropriate
     from the list of available connectors which in  this case is the first INVM connector</p>
     <p> One other thing to notice is that the cluster connection has its reconnect attempts set to 5, this is so it will
         disconnect instead of trying to reconnect to a backup that doesn't exist.</p>
  </body>
</html>