Monitoring in JBoss

While at a client site or within a testing environment, have you ever started to wonder how many users are on the application? How is your application running with regards to memory (heap size)? Are you close to using all of the database connections in the connection pool? For answers to some questions, maybe your application container provides a status (tomcat) or monitoring screen (WebLogic).

To facilitate recording of these statistics when using JBoss, JBoss has included the ability to log/monitor JMX Mbean values. And it's not difficult to install. Once values are being logged, you no longer have to continue refreshing the JMX console to see the values updated.

For installing and monitoring of your web application(s), perform the following steps:

1. Copy monitor XML files into $JBOSS/server/server_name/deploy
2. Copy $JBOSS/docs/examples/jmx/logging-monitor/lib/logging-monitor.jar into $JBOSS/server/server_name/lib
3. Create monitor XML files to monitor JMX MBeans (samples below)

And there you have statistics being saved in a log file...ready for you to parse and create pretty little graphs for the rest of the world to read and understand. For our deployments, we used these logs to track & monitor the following items. As a side affect of monitoring, you also get to see the peak usage times and potentially performance / memory related issues.

• DB connections
• In use
• Available
• Max Connections In Use
• JVM activity
• Heap size
• Threads

For additional reading or research on monitoring within JBoss, check out the following links:

• JBoss Monitoring
• Managing and Monitoring JBoss

DB Connection Monitoring Sample
Here's the XML necessary to monitor a JDBC connection pool (XML comments omitted)

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE server PUBLIC
"-//JBoss//DTD MBean Service 4.0//EN"
"http://www.jboss.org/j2ee/dtd/jboss-service_4_0.dtd">

<server>
<mbean code="org.jboss.services.loggingmonitor.LoggingMonitor"
      name="jboss.monitor:type=LoggingMonitor,name=MY-DSMonitor">

  <attribute name="Filename">${jboss.server.home.dir}/log/my-ds.log</attribute>

  <attribute name="AppendToFile">false</attribute>

  <attribute name="RolloverPeriod">DAY</attribute>

  <attribute name="MonitorPeriod">10000</attribute>

   <attribute name="MonitoredObjects">
      <configuration>
         <monitoredmbean name="jboss.jca:name=MY-DS,service=ManagedConnectionPool"
                         logger="jca.my-ds">
            <attribute>InUseConnectionCount</attribute>
            <attribute>AvailableConnectionCount</attribute>
            <attribute>ConnectionCreatedCount</attribute>
            <attribute>ConnectionDestroyedCount</attribute>
            <attribute>MaxConnectionsInUseCount</attribute>
         </monitoredmbean>
      </configuration>
   </attribute>

  <depends>jboss.jca:name=MY-DS,service=ManagedConnectionPool</depends>
</mbean>

</server>