This metric checks whether a new connection can be established to a database. If the maximum number of users is exceeded or the listener is down, this test is triggered.
The rest of the information in this section is only valid for this metric when it appears in either the Enterprise Manager Grid Control or the Enterprise Manager Database Control (if applicable).
The following table shows how often the metric's value is collected and compared against the default thresholds. The 'Consecutive Number of Occurrences Preceding Notification' column indicates the consecutive number of times the comparison against thresholds should hold TRUE before an alert is generated.
|
Target Version |
Evaluation and Collection Frequency |
Upload Frequency |
Operator |
Default Warning Threshold |
Default Critical Threshold |
Consecutive Number of Occurrences Preceding Notification |
Alert Text |
|
All Versions |
Every 5 Minutes |
After Every Sample |
= |
Not Defined |
0 |
1 |
Failed to connect to database instance: %oraerr%. |
Perl returns 1 when a connection can be made to the database (using Management Agent monitoring connection details), 0 otherwise.
Check the status of the listener to make sure it is running on the node where the event was triggered. If the listener is running, check to see if the number of users is at the session limit. Note: The choice of user credentials for the Probe metric should be considered. If the preferred user has the RESTRICED SESSION privilege, the user will be able to connect to a database even if the LICENSE_MAX_SESSIONS limit is reached.
Related Topics
About Alerts
About the Metric Detail Page
Editing Thresholds
Understanding Line Charts
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