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.
Version:	2.6
Default schedule:	0,10,20,30,40,50 * * *
Requires engine install:	Yes
Compatibility tag:	.[type=‘instance’ & databasetype=‘oracle’]/.[hasengine=‘YES’ & eleven_and_above = ‘1′ & _priv_read_v_parameter = ‘1′ & can_get_grant_create_any_directory=‘1′ ]

Parameters

Name	Default value	Description
alert log name	alert_ORACLE_SID.log	The name of the Oracle alert log.
alert log directory name	DBW_DUMP_DEST	The name of the directory object created with the DDL – “create directory”.
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.

Job Summary

Purpose: The purpose of this job is to monitor and check the Oracle database alert log for any errors.
Why: This job is critically important because it helps in early detection of errors and potential issues in the database system which might affect availability. Early detection allows for timely troubleshooting and mitigation, which can maintain system stability and avoid prolonged downtimes.
Manual checking: You can check this manually in the database by issuing these SQL commands:

SELECT log_text FROM dbw_filelogs WHERE log_type ='alert' AND row_no != 0 ORDER BY row_no;

Key Features

The job targets Oracle instances with specific pre-checks concerning available privileges and configuration.
It uses Oracle internal routines to access and analyse the alert log files.
Automatically verifies the number and size of log entries preventing from uncontrolled log size increase.
Set to trigger every 10 minutes, ensuring timely alert and error monitoring.
Includes numerous checks and fallback mechanisms for reading alert logs efficiently and securely.

Configuration Parameters Overview

Parameter	Description
alert log name	The name of the Oracle alert log.
alert log directory name	The name of the directory object for the alert.log file.
alert log error text	Comma separated values identifying the string patterns (errors) to check in the log.
alert log line HWM (High Water Mark)	Tracks how much of the log file has been checked to avoid rechecking the same content.
alert log max lines	Maximum number of lines in the alert log before a warning is triggered.
alert log max elapsed time	Maximum running time for the check (in seconds) before a warning is triggered.
alert log error text allowed	Specifies error strings which should be ignored during checking.

System Dependencies and Setup

This job requires specific privileges like ‘CREATE ANY DIRECTORY‘ and ‘EXECUTE on SYS.DBMS_LOCK‘.
Dependencies include various internal procedures and table objects provided by dbWatch necessary for managing file logs and executing checks.
Proper setup in the pre-implementation phase ensures the required privileges and directories are configured before the monitoring commences.

Reporting and Alerts

The job includes a reporting template titled “Alert log 11g report” which shows the log text and directory object definitions.
Reports can be used to further analyze the alert log beyond the real-time monitoring, providing insights into patterns or recurring issues.

This comprehensive job setup by dbWatch ensures robust monitoring and management of Oracle database alert logs, crucial for maintaining the integrity and performance of your database environment.