This document lists all the Middleware target metrics that Enterprise Manager monitors.
This preface describes:
This manual contains a chapter for each Middleware target for which there are metrics.
The metrics in each chapter are in alphabetical order according to category.
The information for each metric comprises a description, summary of the metric's "vital statistics", data source (if available), and user action. The following list provides greater detail:
Description
Explanation following the metric name. This text defines the metric and, when available, provides additional information pertinent to the metric.
Metric Summary
Explains in table format the target version, default collection frequency, upload frequency, default warning threshold, default critical threshold, and alert text for the metric.
Data Source
How the metric is calculated. In some metrics, data source information is not available.
User Action
Suggestions of how to solve the problem causing the alert.
This section provides examples of Metric Summary tables that you will see in this document.
When default thresholds are not defined for a metric, only the target version and default collection frequency are available.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 15 Minutes |
The following table provides descriptions of the terminology used with metrics.
| Column Header | Column Definition |
|---|---|
| Target Version | Version of the target, for example, 11g and 12c. |
| Evaluation and Collection Frequency | The rate at which the metric is collected and evaluated to determine whether it has crossed its threshold. The evaluation frequency is the same as the collection frequency. |
| Server Evaluation Frequency | The rate at which the metric is evaluated to determine whether it has crossed its threshold. For server-generated alerts, the evaluation frequency is determined by Oracle Database internals. For example, if the evaluation frequency is 10 minutes, then when the Average File Write Time degrades to the point an alert should trigger, it could be almost 10 minutes before Enterprise Manager receives indication of the alert. This column is present in the Metric Collection Summary table only for Oracle Database 10g metrics. |
| Collection Frequency | The rate at which the Management Agent collects data. The collection frequency for a metric comes from the Enterprise Manager default collection file for that target type. |
| Upload Frequency | The rate at which the Management Agent moves data to the Management Repository. For example, upload every nth collection. The upload frequency for a metric comes from the Enterprise Manager default collection file for that target type. This column is present in the Metric Collection Summary table only when the Upload Frequency is different from the Collection Frequency. |
| Default Warning Threshold | Value that indicates whether a warning alert should be initiated. If the evaluation of the warning threshold value returns a result of TRUE for the specified number of consecutive occurrences defined for the metric, an alert triggers at the warning severity level. |
| Default Critical Threshold | Value that indicates whether a critical alert should be initiated. If the evaluation of the critical threshold value returns a result of TRUE for the specified number of consecutive occurrences defined for the metric, an alert triggers at the critical severity level. |
| Alert Text | Message indicating why the alert was generated. Words that display between percent signs (%) denote variables. For example, Disk Utilization for %keyValue% is %value%% could translate to Disk Utilization for d0 is 80%. |
A metric is a unit of measurement used to determine the health of a target. It is through the use of metrics and associated thresholds that Enterprise Manager sends out alerts notifying you of problems with the target.
Thresholds are boundary values against which monitored metric values are compared. For example, for each disk device associated with the Disk Utilization (%) metric, you can define a different warning and critical threshold. Some of the thresholds are predefined by Oracle.
When a threshold is reached, Enterprise Manager generates an alert. An alert is an indicator signifying that a particular condition has been encountered and is triggered when one of the following conditions is true:
A threshold is reached.
An alert has been cleared.
The availability of a monitored service changes. For example, the availability of an application server changes from up to down.
A specific condition occurs. For example, an alert is triggered whenever an error message is written to a database alert log file.
Alerts are detected through a polling-based mechanism by checking for the monitored condition from a separate process at regular, predefined intervals.
See Also:
See the Oracle Enterprise Manager Concepts manual and the Enterprise Manager online help for additional information about metrics, thresholds, and alertsTo access metrics from the Cloud Control Console, use the All Metrics page:
From the Cloud Control Console, choose the target.
From the target's home page, select the target type name, then Monitoring, and then All Metrics.
Out of the box, Enterprise Manager comes with thresholds for critical metrics. Warning and critical thresholds are used to generate an alert, letting you know of impending problems so that you can address them in a timely manner.
To better suit the monitoring needs of your organization, you can edit the thresholds provided by Enterprise Manager and define new thresholds.
When defining thresholds:
Choose acceptable values to avoid unnecessary alerts, while still being notified of issues in a timely manner.
Adjust your metric thresholds based on metric trends. One of the more important actions you can perform with your monitoring system is to track metric trends for some period of time so you can make informed decisions about what metrics are important as well as what levels your thresholds should be set at.
Set the number of occurrences appropriately. If some events occur only once or twice, for example, you might not need to be notified of them. You can set the number of occurrences of a metric that must be reached before you are notified.
To modify metric thresholds:
From the Cloud Control console, right-click the target name, select Monitoring, and then All Metrics.
From the All Metrics page, select the metric that you want to modify.
Click Modify Thresholds.
In the Modify Thresholds window, you can set values for settings such as:
Warning Threshold
Critical Threshold
Occurrences Before Alert
Note:
You must have at least OPERATOR privilege on the target to make changes. Without OPERATOR privilege, the content of the Metric Threshold table is read-only.Click Save Thresholds to upload the new metric settings to the Management Repository.
The Specifying Multiple Thresholds functionality allows you to define various subsets of data that can have different thresholds. By specifying multiple thresholds, you can refine the data used to trigger alerts, which are one of the key benefits of using Enterprise Manager.The key in specifying multiple thresholds is to determine how the comparison relates to the metric threshold as a whole. What benefit will be realized by defining a more stringent or lax threshold for that particular device, mount point, and so on?For example, using the Average Disk I/O Service Time metric, you can define warning and critical thresholds to be applied to all disks (sd0 and sd1), or you can define different warning and critical thresholds for a specific disk (sd0). This allows you to adjust the thresholds for sd0 to be more stringent or lax for that particular disk.