Submitted by dave on Mon, 12/05/2016 - 17:55
Why use a Metric Extension?The Metric Extension is the evolution of the User Defined Metric. Regular UDMs can be used to gather and store data from targets. Repository-side Metric Extensions let you define new metrics/alerts based on information that is in the EM SYSMAN repository schema.
Creating a Metric ExtensionIn this example we will create a Metric Extension for Data Guard Lag time. This will be measured at the STANDBY instance and will use CURRENT_SCN timestamp vs the database's systimestamp in order to find out exactly how far behind redo application is at the point where the metric is executed.
Go to Enterprise - Monitoring - Metric Extensions menu.
Select Create - Metric Extension
Verifying Metric Extensions
-- List configured targets for the Metric Extensions SELECT * FROM sysman.gc_metric_columns_target WHERE metric_group_name='ME$DG_LAG_TIME' ORDER BY ENTITY_NAME;
Getting current data for our Metric Extension
-- View successfully collected data, all columns SELECT * FROM SYSMAN.MGMT$METRIC_CURRENT WHERE METRIC_NAME='ME$DG_LAG_TIME'; -- View successfully collected data, prettified SELECT TARGET_NAME, METRIC_NAME, METRIC_COLUMN, COLLECTION_TIMESTAMP, VALUE FROM SYSMAN.MGMT$METRIC_CURRENT WHERE METRIC_NAME='ME$DG_LAG_TIME';