MessageBus

MessageBus is a distributed messaging platform built on top of hornetq, and supports java and ruby client. This project includes a patch to HornetQ, and the java and ruby client that works with it.

Prerequisite:

• java 6 or higher
• maven 2
• ant

 $ ./checkout-hornetq.sh

This step first checks out the Jboss HornetQ project, then applies a patch on top of it. It can take a few minutes depending on your internet speed.

If in Unix/Linux:

 $ cd hornetq
 $ ./build.sh bin-distro

If in OSX:

 $ cd hornetq
 $ ./mac-build.sh bin-distro

The server build is located in hornetq/build/hornetq-2.2.22.SNAPSHOT

hornetq-server/config directory contains several config files that you should be aware of. Refer to Hornetq Config for documentation of each config file. There are several mandatory fields required for a working cluster:

• STOMP connector port. MessageBus uses STOMP protocol for communication between clients and servers, and you need to enable it by:

    <acceptors>
      ...
      <acceptor name="stomp-acceptor">
        <factory-class>org.hornetq.core.remoting.impl.netty.NettyAcceptorFactory</factory-class>
         <param key="host"  value="${hornetq.remoting.netty.host:0.0.0.0}"/>
        <param key="protocol" value="stomp" />
        <param key="port" value="61613" />
        <param key="use-nio" value="true" />
      </acceptor>
    </acceptors>

• Persistence directories in hornetq-configuration.xml. You need to point the server to directories that store your journal, paging and bindings. Default is /var/hornetq/*. You need to create these directories before the server can be started.

   <paging-directory>/var/hornetq/paging</paging-directory>
   <bindings-directory>/var/hornetq/bindings</bindings-directory>
   <journal-directory>/var/hornetq/journal</journal-directory>

• Server log location. This is configured in logging.properties. You need to have the directory created. Default is:

 java.util.logging.FileHandler.pattern=/var/hornetq/log/hornetq.log

• jmx directory. In log4j.properties, defines the file jmx logs to. You need to have the directory created. Default is:

 log4j.appender.jmx.File=/var/hornetq/log/jmx.log

Prerequisite: java 6 or higher.

1. Copy the built server to your broker host. After you complete Build the server section, the directory is located in hornetq/build/hornetq-2.2.22.SNAPSHOT
2. Copy your config file directory to your broker host.
3. Run below. $CONFIG_DIR is the path to the config directory.

 $ hornetq-2.2.22.SNAPSHOT/bin/run.sh $CONFIG_DIR

The publishers and consumers have different visibility of the cluster nodes. This is for operational reason. For example, when you want to add a broker, you want to bring it to consumer list first before directing traffic to the new broker, in order to retain real-time delivery. For more about cluster management see Building a Distributed Messaging System.

You will need a load balancer of your choice to direct traffic to your brokers. The purpose of the load balancer is to provide a single host name to distribute TCP/HTTP connections to your brokers. A10 is a good hardware solution. A good software solution is http://haproxy.1wt.eu/.

MessageBus servers uses below ports, and you need to config your load balancer to direct traffic to each port:

• STOMP connection port: 61613. This port accepts connections for transferring messages between the clients and the servers. This port can be configured in hornetq-configuration.xml.
• JMX page port: 8081. This port provides JMX management through HTTP. If your host name is messagebus-hornetq1, then http://messagebus-hornetq1:8081 returns a list of all java beans for you to monitor and RPC. This port number is currently not configurable.
• Health check port: 8083. If your host name is messagebus-hornetq1, then http://messagebus-hornetq1:8083/health returns either a 200 page or 404 page indicating whether the server is up. It reads bindings-directory/health.txt and returns 200 if exists and 404 otherwise.. rm or touch this file to manually control your load balancer. This port number is currently not configurable.

The consumer calls the server on 8081 port for the list of brokers to consume from. It's a file at bindings-directory/serverlist.txt. If your broker list is messagebus-hornetq1, messagebus-hornetq2, messagebus-hornetq3, and the STOMP port is 61613, create this file and write following:

 messagebus-hornetq1:61613
 messagebus-hornetq2:61613
 messagebus-hornetq3:61613

The consumer is configured by default to get this file once every 5 minutes and refreshes connections. You can change this file and wait this much time and expect your consumers are consuming from the new list.

Java and Ruby clients are currnetly supported, located in java/ and ruby/ directory.

See README.mediawiki in mbus-java/

See README.mediawiki in mbus-ruby/

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