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.
Version:	2.8
Default schedule:	7,27,47 * * *
Requires engine install:	Yes
Compatibility tag:	.[type=‘instance’ & databasetype=‘oracle’]/.[hasengine=‘YES’ & (version like ‘11%’) & _priv_read_dba_directories = ‘1′ & can_get_grant_create_any_directory=‘1′]

Name	Default value	Description
listener log name	listener.log	The name of the Listener log file.
listener log path	null	The path name of the Listener log file which is used to create directory object.
listener log directory name	DBW_LISTENER_DIR	The name of the directory object created with the DDL – “create directory”.
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	200000	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.

Purpose: The purpose of this job is to monitor and analyze the Oracle listener log for occurrences of errors and other specific text patterns, and to perform checks based on predefined conditions.
Why: This job is crucial for maintaining the availability and reliability of the Oracle database system by ensuring that potential errors and alerts in the listener log are captured and addressed promptly. By monitoring the listener log, organizations can prevent database downtimes and performance issues, ensuring smooth operations.
Manual checking: You can manually check listener log issues by querying the Oracle system view `dba_directories` and examining the listener log via SQL commands or Oracle tools.

Type of monitoring: The job targets Oracle databases, specifically instances running version 11g.
Permissions required: Adequate privileges are needed for reading specific directories and creating directory objects within the database.
Execution frequency: The default schedule for this job is every 20 minutes (at the 7th, 27th, and 47th minute of each hour).

The job queries the listener log looking for specified error text (defaults to “TNS-”).
It has a mechanism to avoid re-analyzing previously checked lines, using a high watermark system.
Warning statuses are reported if the log file is too long or if the check takes too long to execute.
Certain error texts can be excluded from triggering alerts.

Dependencies: The job relies on other dbWatch tasks related to alert log monitoring.
SQL Operations: Procedures are in place to handle creation and management of directory objects necessary for accessing the log files.
Error handling: The job includes comprehensive error handling routines to capture exceptions and log them accordingly.

Parameter	Description
Listener log name	The filename of the listener log. Default is “listener.log”.
Listener log path	The directory path for the listener log.
Listener log directory name	Oracle directory object that corresponds to the listener log path.
Listener log error text	Specifies error strings to look for in the log.
Listener log line HWM	Keeps track of how many lines have been checked.
Listener log max lines	Maximum allowable number of lines in the log. Exceeding this will trigger a warning.
Listener log max elapsed time	Maximum time the check can run before issuing a warning.
Listener log error text allowed	Specifies error strings that should not trigger an alert.

The job automatically grants required directory creation privileges if not already present.
Checks for the existence and appropriateness of directory objects, creating or recreating them as needed.

The dbWatch Control Center generates reports based on the collected data, providing insights into possible listener log configurations and statuses.
Specific logs of interest are presented in the reports, allowing for easy inspection and further analysis by the database administration team.