Listener log check
Job details
| Name: | Listener log check |
| Platform: | Oracle |
| Category: | Availability |
| Description: | This checks and reads errors from the database listener log. Using Oracle native code to read. |
| Long description: | This checks and reads errors from the database listener log. Using Oracle native code to read. (Oracle 8i only) |
| Version: | 1.5 |
| Default schedule: | 7,27,47 * * * |
| Requires engine install: | Yes |
| Compatibility tag: | .[type=‘instance’ & databasetype=‘oracle’]/.[hasengine=‘YES’ & (version like ‘8%’) & can_get_grant_create_any_directory=‘1′] |
Parameters
| Name | Default value | Description | ||
|---|---|---|---|---|
| listener log name | listener.log | The name of the Listener log file. | ||
| listener log path | ORACLE_HOME\network\log | The path name of the Listener log file. | ||
| listener log error text | TNS- | Defines which strings (errors) the Check must look for. Values for this parameter must be | ||
| listener log line HWM | 1 | Each time the Check read the listener log, it registers how many rows have been checked. | ||
| listener log max lines | 1 | If the listener log has more lines than the value of this parameter, then the Check terminates | ||
| listener log max elapsed time | 60 | Define the maximum elaps time the Check can execute (values are in seconds). If the execution ‘ | ||
| listener log error text allowed | TNS-12500 | Specifies the error strings which are excluded. |
Job Summary
- Purpose: The purpose of this job is to monitor and check Oracle database listener logs for specific errors.
- Why: This job is crucial for maintaining database stability and performance by proactively identifying errors that might affect database connectivity and operations. Monitoring listener logs can help in early detection of issues, such as network failures or unauthorized access attempts, which could lead to downtime or security breaches.
- Manual checking: You can manually check the listener logs in the database by inspecting the Oracle listener logs located usually in ORACLE_HOME/network/log directory. Use the following command to view the log:
less ORACLE_HOME/network/log/listener.logJob Configuration Details
- Category: Availability
- Listens to: Database instance (Oracle Type) which satisfies specific condition (has engine, version starting with ‘8′, and can get grant create any directory).
- Default Schedule: The job is scheduled to run at the minutes 7, 27, and 47 of every hour.
- Dependencies: This job depends on its previous runs (it is self-referencing) and other alert logging checks.
Execution Details
This job uses an Oracle stored procedure to read and analyze the listener logs for predefined errors. If certain conditions are met (like exceeds max lines or execution time), a WARNING status is returned, otherwise, an OK status might be reported.
Report Generation
This job generates a report titled “Listener log,” which displays data collected during the log check. It includes:
Status on check information
- Shows configuration and status: List of the listener log file.
Directory objects
- Shows directory definition: Table listing directory names and paths used by the listener in the database.
Implementation Notes
The SQL implementation used in this job makes use of Oracle specific functionality to access and manage file system-based log files. The procedure checks for errors defined by the job parameters and respects the acknowledgment and high water mark lines to optimize log file read operations.
Dependencies and Execution
Dependencies include:
- Self-reference: Ensuring the check acknowledges its own output to maintain continuity.
- File Log objects: Relies on file log procedures and statuses that may be shared with other alert log checks.
- Cleanup: Failures in dependencies can trigger cleanup operations to ensure system stability.
Installation and Upkeep Details
- The procedure is created to dynamically adapt to various instances by using placeholders in names.
- It has settings that allow force installation and does not support express installation which implies manual review and setup is required.
- Alterations to the procedure require recompilation indicating periodic updates may be implemented to enhance its functionality or adapt to system changes.