Blog | Dec 18, 2012

12c EM Metric Extensions – An Alternate to UDM

12c EM Metric Extensions – An Alternate to UDM

Finally, I decided to join the blogging community. And, what better subject to write on than 12c EM. As some of you may know, 12c EM is the next version of Oracle’s monitoring software. Of particular interest to me is a feature – 12c EM Metric Extensions.

When it came to setting up monitoring of Oracle EBS environments, one of the challenges for us was configuring “out-of-box” monitoring in 10g/11g EM. One option is to configure specialized scripts (SQL/SH) for database and host targets. These type of metrics in 11g/10g EM where known as User Defined Metrics (UDM). UDM is widely used across all clients’ to monitor mainly EBusiness Suite targets like Concurrent Manager, Workflow Managers or Long Running jobs. However, one of the drawbacks of UDMs, in pre 12c EM releases, is that they were only applicable to host and database target types.

Since 12c Metric Extensions (MEs) represents a major improvement over UDMs (User Defined Metrics) -in terms of code maintenance and ability to deploy to large number of targets - I would like to share my knowledge on the subject. Though Metric Extensions do not allow us to customize query for any specific target. 12c EM introduces Metric Extensions for the same goal. Recently, we have deployed the same at a customer as part of their grid upgrade project.

Another major feature here is Metric Extension Library. In EM 11g/10g, there was no central location to store and maintain version control of User Defined Metrics. A User Defined Metric could only be created as a Target related object, which means one has to pick a certain Target (Host or Database) and create a UDM. Then by including your UDM in a Monitoring Template you would be able to deploy the UDM to other Targets.

Prior to 12c EM, there was no support for the Development Lifecycle for metric extensions. 12c EM Metric Extensions supports the following Development and Deployment processes.


  1. Create Metric Extension and test it against a specific Target to make sure it is working correctly
  2. Make any modifications necessary as per its requirements.


  1. Deploy the Metric Extension to any number of Test Targets
  2. Review Metric Data and check for any issues
  3. Configure Alert notification and Test the result from the Metric Extension


  1. Publish the Metric Extension by means of a Monitoring Template so that it is available in Metrics Events list for any target to use it

 Below diagram further describes the Metric Extension Development Lifecycle Steps:

 12c EM Metric Extensions resized 600

This excellent feature eradicates the need for redundant deployment of UDM on each target. It further provides you with the ability to extend Oracle's monitoring capabilities to monitor conditions specific to your IT environment. This provides you with a comprehensive view of your environment. Furthermore, metric extensions allow you to simplify your IT organization's operational processes by leveraging Enterprise Manager as the single central monitoring tool for your entire datacenter instead of relying on other monitoring tools to provide this supplementary monitoring.

I hope readers of this article are able to use this novel feature of 12c EM.