This chapter provides information about the listener metrics.
For each metric, it provides the following information:
Description
Metric table
The metric table can include some or all of the following: target version, default collection frequency, default warning threshold, default critical threshold, and alert text.
You can use Enterprise Manager to manage Oracle listener targets. From the Enterprise Manager Listener home page, you can monitor key metrics that can help determine the performance and availability of the listener and help you troubleshoot potential performance problems.
This metric category contains a set of metrics that provide general information about the listener target. For more information, see the section on Listener Administration in the Oracle Database Net Services Administrator's Guide.
This metric provides the alternative name for the listener. On the Metric Detail page, you can see the value of this metric only when you select one of the Real Time refresh options. The alias also appears on the Listener home page.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 15 Minutes |
Data Source
The data is derived from the STATUS command of the Listener Control Utility.
This metric shows whether or not a password is required to run specific commands with the Listener Control Utility.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 15 Minutes |
Data Source
The data is derived from the STATUS command of the Listener Control Utility.
This metric lists the System Identifiers (SIDs) for the services monitored by the listener.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 15 Minutes |
Data Source
The list of SIDs for the listener is stored in the listener.ora configuration file.
This metric indicates whether or not the listener can respond to queries from an SNMP-based network management system.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 15 Minutes |
Data Source
The data is derived from the STATUS command of the Listener Control Utility.
This metric represents the date and time when the listener was last started. On the Metric Detail page, you can see the value of this metric only when you select one of the Real Time refresh options. This metric also appears on the Enterprise Manager Listener home page.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 15 Minutes |
Data Source
The data is derived from the STATUS command of the Listener Control Utility.
This metric displays the protocol, host, and port information for the listener. On the Metric Detail page, you can see the value of this metric only when you select one of the Real Time refresh options. The TNS address also appears on the Listener home page.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 15 Minutes |
Data Source
The TNS address of the Listener is defined in the listener.ora configuration file.
This metric represents the level of tracing currently enabled for the listener. Tracing can be used to troubleshoot problems with the listener by saving additional information to the trace file. For more information about the trace levels you can set for the listener, see the information about the Listener Control Utility in the Oracle Database Net Services Reference Guide 10g Release 2 (10.2).
On the Metric Detail page, you can see the value of this metric only when you select one of the Real Time refresh options.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 15 Minutes |
Data Source
The data is derived from the STATUS command of the Listener Control Utility.
This metric provides the version of the listener software. On the Metric Detail page, you can see the value of this metric only when you select one of the Real Time refresh options. This metric also appears on the Enterprise Manager Listener home page.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 15 Minutes |
Data Source
The data is derived from the STATUS command of the Listener Control Utility.
This metric category collects configuration data for the listener such as ports, protocol, and host. It is calculated using the lsnrctl status <listener Name> command on all platforms.
This metric category collects configuration data for the services registered to the listener (for example, service name, SID, or service).
It is calculated using the lsnrctl status <listener Name> command on all platforms.
This metric category contains a set of metrics that provide information about the number of connections supported by the listener over a period of time. For more information, see the section on Listener Administration in the Oracle Database Net Services Administrator's Guide.
This metric provides the number of connections established since the listener was last started.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 15 Minutes |
Data Source
The data is derived from the SERVICES command of the Listener Control Utility.
User Action
If you are experiencing performance issues with the database or other services supported by the listener, review the historical values of this metric to determine whether or not the performance problems are caused by excessive load on the listener or host.
This metric reports the average number of connections per minute that were established with the listener.
Data Source
The data is derived from the Listener Control Utility.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 15 Minutes |
User Action
If you are experiencing performance issues with the database or other services supported by the listener, review the historical values of this metric to determine whether or not the performance problems are caused by excessive load on the listener or host.
This metric reports the number of connections to the listener that were refused. A connection can be refused for a variety of reasons, including situations where the database or other listener service is down, or if the connection timed out.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 15 Minutes |
Data Source
The data is derived from the SERVICES command of the Listener Control Utility.
User Action
If Enterprise Manager reports a high number of refused connections, check the availability and performance of the database or other services supported by the listener.
This metric reports the average number of connections that were refused per minute.
| Target Version | Collection Frequency |
|---|---|
| All Versions | Every 15 Minutes |
Data Source
The data is derived from the Listener Control Utility.
User Action
If Enterprise Manager reports a high number of refused connections, check the availability and performance of the database or other services supported by the listener.
This metric category contains the response and status metrics that provide performance information about the Listener.
This metric represents the time (in milliseconds) that it takes for the Listener to respond to a network request (ping).
| Target Version | Evaluation and Collection Frequency | Default Warning Threshold | Default Critical Threshold | Alert Text |
|---|---|---|---|---|
| Not Available | Every 5 Minutes | 400 | 1000 | Listener response to a TNS ping is %value% msecs. |
Data Source
The value of this metric is derived using the TNSPING command. For more information about the TNSPING command, see the Oracle Database Net Services Administrator's Guide.
User Action
If the listener response time consistently exceeds the threshold, then there can be a number of possible causes, such as slow DNS resolution, network congestion, or other network-specific factors. For more information about investigating these issues, see the My Oracle Support Note, Oracle Net Performance Tuning (Doc ID 67983.1):
https://support.oracle.com/epmos/faces/DocumentDisplay?id=67983.1">>https://support.oracle.com/epmos/faces/DocumentDisplay?id=67983.1
This metric returns a value of 1 if the listener is up and running. It returns a 0 if the listener is unavailable.
| Target Version | Evaluation and Collection Frequency | Default Warning Threshold | Default Critical Threshold | Alert Text |
|---|---|---|---|---|
| Not Available | Every 5 Minutes | Not Defined | 0 | The listener is down: %oraerr%. |
Data Source
The data is derived from the from the STATUS command in the Listener Control Utility. For more information, see the Oracle Database Net Services Administrator's Guide.
User Action
When the listener is down, users cannot access the database or other services on this host. Review the troubleshooting information in Oracle Database Net Services Administrator's Guide.