Alert log check

Job details

Name:	Alert log check
Platform:	Oracle
Category:	Availability
Description:	This check reads and looks for errors in the database alert log.
Long description:	This check reads and looks for errors in the database alert log. Uses Oracle internal routines to read files. (Oracle 8i only).
Version:	2.5
Default schedule:	0,10,20,30,40,50 * * *
Requires engine install:	Yes
Compatibility tag:	.[type=‘instance’ & databasetype=‘oracle’]/.[hasengine=‘YES’ & (version like ‘8%’) & _priv_read_v_parameter = ‘1′ & can_get_grant_create_any_directory=‘1′ ]

Name	Default value	Description
alert log name	alert_ORACLE_SID.log	The name of the Oracle alert log.
alert log path	ORACLE_HOME\admin\ORACLE_SID\bdump	The path name of the Oracle alert log.
alert log error text	ORA-	Defines which strings (errors) the Check must look for. Values must be separated with commas (,).
alert log line HWM	1	Each time the Check read the alert log, it registers how many rows have been checked. The next time
alert log max lines	200000	If the alert log has more lines than the value of this parameter, then the Check terminates and
alert log max elapsed time	60	Define the maximum running time the Check can execute (values are in seconds). If the execution time reach
alert log error text allowed	NULL	Specifies the error strings which are excluded.

Purpose: The purpose of this job is to monitor and track errors in the Oracle database alert log for potential issues.
Why: This job is important to ensure the stability and health of the Oracle database by actively searching for errors such as ORA- errors in the alert log files. It helps in proactive troubleshooting by identifying problems early, which might otherwise be missed and could lead to database downtime or performance degradation.
Manual checking: You can check this manually in the database by issuing the following SQL command:

SELECT log_text FROM ";;dbw~schema;;".dbw_filelogs WHERE log_type ='alert' ORDER BY row_no;

The monitoring job targets instances of Oracle databases, specifically version 8 (as indicated by ‘version like ‘8%’ in the compatibility query).
It focuses on the availability category, checking for errors using Oracle’s internal routines only for Oracle 8i versions.
The default schedule for this check is set to occur every 10 minutes (at minutes 0, 10, 20, 30, 40, and 50 of each hour).

This job includes a specific query to read the Oracle alert log file, looking for predefined error strings (specified by the parameter “alert log error text”) and monitoring the number of lines processed to ensure it does not read past the high water mark set by the user.
The maximum number of log lines the job can process before issuing a warning is configurable, as well as how long the job can run before timing out, to prevent it from impacting database performance.
Special handling is included to exclude certain error strings which are deemed allowable (specified by the “alert log error text allowed” parameter).
If the alert log contains more lines than specified, or if the job exceeds the maximum allotted time for checking the log, it will terminate and return a warning status.

The job relies on several dbWatch engine procedures and objects including procedures for checking file logs and retrieving file log statuses.
Upon failure, there are cleanup routines specified for certain dependent objects to ensure that no erroneous data is left that might affect subsequent checks.

Generates reports based on the results of the alert log check, including displaying collected log texts and summaries about them.
Is scheduled to provide a report hourly, offering insights into the configuration and status of the monitored alert log.

Dependency	Object	Description
Procedure	alert_log	Main procedure initiating the alert log check
Procedure	get_filelog_status	Retrieves the status after logfile check
Table	DBW_FILELOGS	Used to store logfile data within dbWatch engine
Procedure	check_filelog	Used by various log checking procedures within dbWatch

The job configuration allows for updates to critical parameters such as log name and path depending on the Oracle version and instance name dynamically upon each execution.
Allows forceful installation and updates to ensure that the latest job configuration is in use without manual intervention.

It is applicable primarily to older Oracle databases (8i versions), making it specialized but critical for systems still running these versions.
Users must ensure regular truncation of alert logs and adjust the thresholds as necessary to adapt to their specific database workloads and operations environment. Regular updates and checks on the job’s performance are recommended to ensure optimal monitoring.