Set Up High-Availability Open MQ with MySQL Cluster

Version 1.0
Author: Phuong Nguyen
Last edited 07/15/2008

Introduction

This guide shows how to configure Open MQ with two brokers and MySQL Cluster with two storage nodes and one management node that provides high-availability for a minimal hardware configuration. This setup requires four servers.

Server Topology

MySQL Cluster requires a minimum of three servers to provide true redundancy: two MySQL/NDB servers and one management server. As the management server is a light-weight process and does not use many resources, we can also run MQ Broker instance 1 on the same machine. This means that a fourth server is needed for the 2nd Broker instance. This topology is known as the Separate Tier Topology; the Broker instances and the MySQL/NDB nodes are on different machines (hence the name separate tier).

Another variation known as the Co-located Topology, run the Broker instance and MySQL server on the same machine (hence the name co-located) so the NDB node can run by itself on a single server. For simplicity, we'll use the Separate Tier Topology in this setup.

Server 3

Broker Instance 1

Management Node

Server 4

Broker Instance 2

Server 1

MySQL Node 1

NDB Node 1

Server 2

MySQL Node 2

NDB Node 2

Step 1: Download and install MySQL Cluster 6.2

Download the appropriate MySQL Cluster binary distribution for you platform. Download link

Alex Davies has written an excellent writeup on MySQL Cluster: Two webserver setup. Please follow the steps described in his guide to setup MySQL Cluster with two storage nodes. If all goes well, you should have MySQL/NDB node running on both Server 1 and Server 2 with the management node running on Server 3.

Step 2: Download Open MQ 4.2

Download the appropriate Open MQ binary distribution for you platform. Download link

Step 3: Install Open MQ Community Bundles (Compressed Archive)

Do the following to install MQ on both Server 3 and Server 4:

Unzip the binary (.jar) bundle
Edit the file $TOP/mq/etc/imqenv.conf to set IMQ_DEFAULT_JAVAHOME to JDK 1.5 or later version
Generate the instance configuration file by starting the broker:

cd $TOP/mq/bin
./imqbrokerd -tty
Type CTRL-C to shutdown the broker
Edit the broker’s instance configuration file:

$TOP/mq/var/instances/imqbroker/props/config.properties
Set the following JDBC-related properties in the broker’s instance configuration file:

imq.cluster.ha=true
imq.brokerid=broker1
imq.cluster.clusterid=mqcluster
imq.persist.store=jdbc
imq.persist.jdbc.mysql.user=<db_username>
imq.persist.jdbc.mysql.password=<db_user_password>
imq.persist.jdbc.dbVendor=mysql
imq.persist.jdbc.mysql.property.url=jdbc:mysql://<Server_1_hostname>:3306,<Server_2_hostname>:3306/mqdb
imq.persist.jdbc.mysql.tableoption=ENGINE=NDBCLUSTER

Note: We use broker1 as the brokerID for the 1st instance and mqcluster as the clusterID. You'll also need to specify the username and password for the database, and the hostname of Server 1 and Server 2 for the JDBC's URL property of your setup.
Place a copy of MySQL Connector/J JDBC driver in the following directory: Download link
$TOP/mq/lib/ext
Create the database schema needed for MQ persistence:

cd $TOP/mq/bin
./imqdbmgr create tbl

Note: You'll only need to do this step once on either MQ installation (Server 3 or Server 4)

For Server 4, change the brokerID to broker2 in the broker's configuration file.

Step 4: Start the Broker Clusters

Start the broker on both Server 3 and Server 4

cd $TOP/mq/bin
./imqbrokerd -tty
Check the output on the console or the broker's log file for log message B1179 & B1071 to verify that Broker 1 is connected to Broker 2 in an HA cluster; below is a snippet from an actual log file:

...

[15/Jul/2008:15:14:04 PDT] [B1185]: Starting heartbeat to broker2
[15/Jul/2008:15:14:04 PDT] [B1181]: Added heartbeat endpoint /129.145.130.96:7676 [brokerID=broker2, brokerSession=4896287081875276288] (seq#=0, ts=1216160044852, interval=2, len=207)
[15/Jul/2008:15:14:04 PDT] [B1179]: Activated broker
        Address = mq://129.145.130.96:7676/?instName=imqbroker&brokerID=broker2&brokerSessionUID=4896287081875276288&ha=true&storeSessionUID=4896287081875276288
        StartTime = 1216160039901
        ProtocolVersion = 410
        HeartbeatHost = 129.145.130.96
        HeartbeatPort = 7676
[15/Jul/2008:15:14:04 PDT] [B1071]: Established cluster connection to broker mq://129.145.130.96:7676/?instName=imqbroker&brokerID=broker2&brokerSessionUID=4896287081875276288&ha=true&storeSessionUID=4896287081875276288[/129.145.130.96:35654]

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