EM 12c, EM 13c: How to Prevent Alerts from the Server Adaptive Threshold Metric (Server_Adaptive_Threshold_Metric) Starting with Enterprise Manager 126.96.36.199 Cloud Control
Last updated on MAY 06, 2017
Applies to:Enterprise Manager for Oracle Database - Version 188.8.131.52.0 and later
Information in this document applies to any platform.
To prevent alerts from the 'Server Adaptive Threshold' metric in Enterprise Manager 184.108.40.206 and later versions of Cloud Control.
An example of an email alert from the server_adaptive_threshold_metric:
Target type=Database Instance
Message=Metrics "Physical Writes Per Sec" is at 2.449
Event reported time=Sep 23, 2014 2:23:01 PM BST
Associated Incident Id=7262
Associated Incident Status=New
Associated Incident Owner=
Associated Incident Acknowledged By Owner=No
Associated Incident Priority=None
Associated Incident Escalation Level=0
Event Type=Metric Alert
Metric=Physical Writes Per Sec
Metrics "Physical Writes Per Sec" is at 2.449
Incident created by rule (Name = Incident management rule set for all targets, Create incident for critical metric alerts [System generated rule]).
An example of the alert in incident manager:
There have been some changes to the way that metrics are evaluated in Cloud Control 220.127.116.11 (when used in conjunction with the 18.104.22.168 or higher database plug-in). The biggest change is that most metrics which were previously evaluated by the server generated alert system (in older versions of Enterprise Manager) will now be evaluated purely by the agent. In 22.214.171.124 and higher the new behaviour is that all metrics where it is possible to set a threshold (via the 'metric and collection settings' screen) will be evaluated by the agent and the server generated alert system is no longer relied on. See <Note:1680788.1> "EM 12c, EM 13c: Changes to Oracle Database Monitoring in Enterprise Manager Cloud Control 126.96.36.199 and later with DB-Plugin 188.8.131.52 and later" which explains this further.
The 'server adaptive threshold' metric is *not* one of the metrics which uses the 'new behaviour'. It is not possible to set thresholds for the 'server adaptive threshold metric' in Enterprise Manager's 'metric and collection settings' screen nor is it possible to disable this metric via the EM interface. This means that the 'server adaptive threshold' metric will still be evaluated via the server generated alert system and will generate an alert according to the thresholds which are set in sys.dba_thresholds on the database.
Please note that the server adaptive threshold metric has been provided for backwards compatibility only for customers who need to continue to utilize the server generated alert system for database adaptive threshold metrics. However, EM 184.108.40.206 and higher also provides a new "Adaptive Threshold" mechanism, which is controlled by the Enterprise Manager metric alert subsystem and which does not rely on the server generated alert system or the settings in sys.dba_thresholds. This is the preferred method to be used when working with adaptive thresholds (thresholds which are not set statically but which self modify over time according to user specifications). These new adaptive thresholds features can be found under Advanced Threshold Management and can be accessed as follows:
- Database Home Page Oracle Database pull-down menu
- Monitoring /Metric and Collection Settings
- scroll down to Related Links/Advanced Threshold Management
The 'server adaptive threshold' metric will fire when the thresholds are crossed which are set on the database itself (in sys.dba_thresholds). This means that if any of the following metrics, have thresholds set in sys.dba_thresholds, the server adaptive threshold metric could fire if the thresholds are crossed:-
For a database which is newly added to EM 220.127.116.11 Cloud Control (or higher) it is likely that the thresholds will not be set on the database in sys.dba_thresholds for these metrics. This is because EM 18.104.22.168 (and higher) provides a different set of metrics (mostly under 'Throughput') For example:
Throughput/Average Active Sessions
Throughput/Physical Reads Per Sec
To see the full list, go to
- Database home page
- Oracle Database (drop down menu)
- Monitoring/metric and collection settings/Choose "All metrics"
- Go to database home page/performance/adaptive thresholds
- locate the metric, click on Edit Thresholds
- Setting the thresholds in this way, will update sys.dba_thresholds.
How this metric can be influenced by older Enterprise Manager products
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