15.1 Introduction to Monitoring the OC4J Environment

The Oracle Enterprise Manager 10g Application Server Control console is a JMX-compliant, web-based user interface that allows you to monitor applications within OC4J. Monitoring involves understanding your OC4J environment, monitoring the OC4J instances in that environment, and monitoring the applications you have deployed. Monitoring OC4J involves understanding your OC4J environment, monitoring the OC4J instances in that environment, and monitoring the applications you have deployed.

Read this chapter to understand:

• How to Monitor an OC4J Instance

• How to Monitor the Cluster Topology

• How to Monitor Deployed Applications

• How to Monitor Web Module and EJB Module Performance

• How to Monitor JVM Metrics

15.1.1 How to Monitor an OC4J Instance

To monitor the performance of a particular OC4J instance, navigate to the OC4J Home page as shown in Figure 15-1.

Figure 15-1 OC4J Home

Description of "Figure 15-1 OC4J Home"

1. Review the Response and Load chart on the OC4J Home page to obtain a glimpse of how many users are accessing the instance and how quickly the instance is responding to requests. Select a refresh rate from the View Data drop-down menu to refr.esh the Response and Load chart automatically over a period of time.

2. Click Performance on the OC4J Home page. Figure 15-2 displays key performance metrics, such as heap usage, Oracle Enterprise Manager JDBC usage, Servlet and JSP performance, and EJB performance within the OC4J instance.

   Figure 15-2 OC4J Home: Performance

   
   Description of "Figure 15-2 OC4J Home: Performance"
   
   

3. From the OC4J Performance page, select a refresh rate from the View Data drop-down menu to refresh the data and analyze the value of the performance metrics over a period of time

For more information about the metrics displayed on this page, see Summary of the OC4J Performance Metrics.

15.1.2 How to Monitor the Cluster Topology

Monitoring begins from the Cluster Topology page as shown in Figure 15-3.

Figure 15-3 Cluster Topology

Description of "Figure 15-3 Cluster Topology"

This page provides you with a high-level overview of your OC4J environment. You can use the Cluster Topology page to see how the Oracle Application Server contains components, such as OC4J and Oracle HTTP Server, and how OC4J contains deployed applications.

You can then use the Cluster Topology page to drill down to a specific OC4J instance home page, or to a specific application Home page.

15.1.3 How to Monitor Deployed Applications

If you are interested in a particular application, click the application name on the Cluster Topology page to drill down directly to the application home page.You can view a list of the applications deployed to a particular OC4J instance by clicking Applications on the OC4J Home page. The Applications page also provides a set of key performance metrics for each application that you can scan for a glimpse of how each application is performing. Click the application name to display the Application Home page. Click Performance on the Application Home page to display a series of performance charts. Select a refresh rate from the View Data drop-down menu to refresh the charts automatically over a period of time. Look for spikes and trends in the performance data.For more information about the metrics displayed on this page, see Summary of the OC4J Performance Metrics.

15.1.4 How to Monitor Web Modules and EJB Module Performance

In addition to monitoring deployed applications, you can also monitor individual web modules.

To monitor web and EJB modules:

1. Navigate to the OC4J Home page.

2. Click Applications to display the Applications page.

3. Select Modules from the View drop-down list.

4. Click the name of the web module or EJB module you want to monitor.

5. Click Performance.

   Oracle Enterprise Manager displays the Performance page as shown in Figure 15-4. This page provides key performance metrics for the selected Web module or EJB module. For more information about the metrics displayed on this page, see Summary of the OC4J Performance Metrics.

   Figure 15-4 EJB Module

   
   Description of "Figure 15-4 EJB Module"
   
   

15.1.5 How to Monitor JVM Metrics

OC4J executes on the Java Virtual Machine (JVM) of the standard Java Development Kit (JDK). From the Application Server Control Console, you can configure an OC4J instance to run on multiple JVMs, and you can monitor and compare the performance of JVMs associated with the OC4J instance

Oracle application Server offers several methods for monitoring the JVM:

• If you have installed OC4J as part of an Oracle Application Server environment, you can monitor JVM performance using the JVM Metrics page and the OC4J JVM performance page.

• In the standalone OC4J environment, and in the Oracle Application Server environment, you can monitor a JDK 5.0 JVM by setting an OC4J Server property.

15.1.5.1 Monitoring JVM Metrics in the Oracle Application Server Environment

If you are running OC4J in an Oracle Application Server environment, then you can monitor a set of Dynamic Monitoring Service (DMS) metrics for each JVM. These metrics are unavailable in the standalone OC4J environment.

To view the DMS JVM Metrics in the Oracle Application Server environment:

1. Navigate to the OC4J Home page.

2. Locate the Virtual Machines field in the General section of the OC4J Home page.

3. Click the number that indicates how many JVMs are configured for the OC4J instance.

   Enterprise Manager displays the JVM Metrics page, which provides a summary of key metrics for all the JVMs configured for the selected OC4J instance. You can use this table to compare the performance of multiple JVMs.

4. For more detailed information, click the name of the JVM you want to monitor.

   Enterprise Manager displays the OC4J JVM page, which provides a set of charts and numeric metrics that give you a detailed picture of how the JVM is performing. Use the View Data drop-down list to select a refresh interval. You can then view the changes in the performance charts over a period of time.

15.1.5.2 Monitoring J2SE 5.0 JVM Metrics

Before you can monitor the J2SE 5.0 JVM metrics from the Application Server Control Console, you must be sure that your system meets the following requirements:

• You must be running OC4J on JDK 5.0.

  The current OC4J release can run on JDK releases 1.4.2 and 5.0. To monitor the JVM metrics, you must be running on JDK 5.0 (1.5).

• You must make sure that the jmxremote system property has been set.

If you are sure your system meets these requirements, you can view the JVM metrics as follows in both the Oracle Application Server environment and in the standalone OC4J environment.

To view the DMS JVM Metrics in the Oracle Application Server environment:

1. Navigate to the OC4J Home page.

2. Locate the Virtual Machines field in the General section of the OC4J Home page.

3. Click the number that indicates how many JVMs are configured for the OC4J instance.

   Enterprise Manager displays the JVM Metrics page.

4. For more detailed information, click the name of the JVM you want to monitor.

   Enterprise Manager displays the OC4J JVM page.

5. Scroll to the Related Links section of the page and click J2SE 5.0 Metrics.

To view the DMS JVM Metrics in the standalone OC4J environment:

1. Navigate to the OC4J Home page.

2. Click Performance to display the OC4J Performance page.

3. Scroll down to the Related Links section of the page and click J2SE 5.0 Metrics.