Alert Log allows for handling of Oracle Alarms. The configuration of the Alert Log can be done by entering the Global Administration are for Oracle | Alert Log.
There are three defaults set for Oracle Log:
The Agent connects at the Database level (windows and UNIX) and hence reads the information from the alert log.
Important: in versions of the Oracle cartridge prior to 188.8.131.52 no OS connection is required.
Alarms will be fired each time when event occurs, does not depends on previous alarms and never cleared automatically.
Checking the Alarms fired by Alert Log
The alarms fired by Alert Log appear under the Instance column in the Alarm pop-up screen. Clicking the Alert log alarms allows further Investigation to take place.
Matching list and Ignore list
The alarms of Alert log can be configured by using matching list and ignore list. The Match list can be edited to add required alert messaged, edit the existing records in the list, enable or disable alarms for certain alert messages. Updating the Matching list will not filter the alert messages from the alert log screen, removing the record from Matching list will map the message with severity Informational under Other type.
Adding the alert message to ignore list will filter the message out of alert messages screen.
Alert Log Dashboard: Configuration | Alert Log
The Alert Log Dashboard displays all alert log messages, except messages defined in "Ignore List". Messages that match the "Match List" patterns displayed under pre-defined name, category and severity. All the rest will appear under name "Other", type "Oracle alert messages" with severity "Informational".
Why do I see "create table" in my agent log?
The Alert Log collection uses an external table feature for its internal functionality, this is why a create table message might be observed in log files.
Why I cannot see old trace file by click?
Trace file monitoring is an online collection that reads the trace file by request originated by clicking on a trace file link in an alert log record. As this is an online collection (the information is not stored in the repository), the data is available only if the trace file still exist in the file system and can be accessed.
How is the alert log parsed?
In cartridge versions before 184.108.40.206, the cartridge creates external table that keeps the rows that will be parsed by the agent (no OS connection is required). The maximum number of rows that are read is defined in Number of rows collected from log configuration parameter. The agent parses and submits the retrieved rows in the following way:
Oracle cartridges beginning with 220.127.116.11 and higher use a OS connection to collect Alert Log data.
Does CREATE ANY DIRECTORY permission really required for Alert log collection?
In cartridge versions prior to 18.104.22.168, the Alert Log collection creates an oracle directory that points to background_dump_dest OS directory in order to read oracle alert.log. In order to achieve that goal, GRANT CREATE ANY DIRECTORY TO &USER_NAME permission is used by Alert log collection. In general it can be revoked, however if the directory will change/become invalid/etc`, the agent will not be able to recreate it automatically and the collection will fail.
However, it is possible to quickly revoke that grant and still maintain Alert log collection as follows:
Does the Alert Log monitoring requires drooping and creating of QSI_ALERT_TAIL table?
Yes for Oracle cartridge versions before 22.214.171.124. Each time when running, the Alert Log collection creates external table pointing to the last x lines in alert.log file (500 by default, could be customized via Agent Administration), reads the content of the file and drops the table.