The answer to using Java Management Extensions(JMX) within Oracle Enterprise Manager Cloud Control is using Metric Extensions. Metric extensions provide you with the ability to extend Oracle’s monitoring capabilities. I will show you how to create an extension to monitor a WebLogic Messaging Bridge. You can use other methods to create metric extensions, for example via the EMCLI. This will not be covered in this blog.
First of all, you have to have sufficient permissions within Cloud Control to be able to create metric extensions. Second is if you want to execute or test the given example you will need to have a JMS server.
Navigate to Cloud Control and login.
Creating a draft.
Navigate via your Enterprise Summary to “Metric Extensions”.
Navigate within the “Actions” pane from “Create” to “Metric Extension”
Because we are going to monitor a messaging bridge, the target type will be set to “Oracle WebLogic Server”. We will use the Java Management Extensions (JMX) adapter to retrieve the attributes and results from the server the extension will be deployed on.
Below the “General Properties” section there is a section regarding the collection schedule to enable data upload and to configure the upload interval.
Selecting columns and thresholds.
In the “Select Target” field, you will have to select a server om which a WebLogic Messaging Bridge is active. This will be the JMS server you are planning to deploy your metric extension on.
We want to retrieve the status of the bridge.
In the “Enter MBean Pattern” field type: “com.bea:Type=MessagingBridgeRuntime,*”
Click on “List MBeans”.
You will see a list of bridges that are deployed on you JMS server. If this is not the case verify you have active bridges in your JMS server configuration.
Scroll down and you will be able to select the attributes you want to retrieve.
Click on the “Select” button and click on “Next” to go to the next page.
Click on the “State” column and click on “Edit”.
Select “Comparison Operator” on value “Matches” and type in “Inactive” in the warning or critical field.
An alert will be triggered based on these values.
The “Number of Occurrences Before Alert” field can be used to set the amount of times the threshold can be breached before an alert is created. Per default this value is set on “1”.
You can also use the “Compute Expression” section to calculate a value for this column based on the values in the other columns. If you would like to use this function I would recommend to create another column in which you can populate the values you have calculated.
Example Compute Expression operation:
(DestinationInfo_Name __contains ‘error’)
This command will check if the “DestinationInfo” column contains a row with the word “error” in it. If this is the case it will return a “1” for that row. If this is not the case it will return a “0” for that row.
Testing your metric extension.
Press “Next” to test your metric on the target.
Add the JMS server to run the test.
As you can see the column “Bridge state” will have the value “Active”.
After testing the metric with success navigate to the last page.
The last page is the “Review” page.
Click “Finish” to create the extension.
Deploying and publishing your metric extension.
Navigate to your metric extension and click on the “Actions” pane and click on “Save as Deployable Draft”. To be able to deploy your metric.
If you do not want to change your metric extension you can publish your metric by clicking on “Publish Metric Extension”.
An example on how this metric would look like on the JMS server:
