Monitoring the Log Area

The log area is dimensioned when the database is created. A full log area can cause the database to hang.

Procedure

Monitor the log area. Use the following displays:

Database Alert Monitor, Log Area

Database Assistant, Database Fill Level, Log Area

Monitor the database logs. To do this, use the Current Messages display in the Database Assistant, for example.

Monitor the tasks. To do this, use the Task Manager display in the Database Assistant, for example.

Monitor the log backup and the archiving for the backup files. To do this, use the DBA History display in the Database Assistant, for example.

Critical Situations

?     A red alert is generated in the Database Alert Monitor if the amount of free space in the log area falls below 10%.

?     Messages are written in the database log files informing you that the log area is almost full. This takes place long before the log area is entirely full (from a filling level of 50%):
2005-08-14 09:26:36      0x7EC WRN 52438 LOG     log used 50(499 pages left)

?     If the log area is actually full, one task has the state LOG_FULL, and the other tasks have the state vsuspend until more space becomes available. The task states are logged in the database log.

If the log area is at risk of filling up, you must create a backup log right away (starting an action immediately). The suspended tasks continue with their work as soon as the first log segment is backed up.

You can decide whether a new log volume needs to be added. To do this, use the Database Manager (for example, Database Manager GUI, Creating, Displaying and Deleting Volumes).

Avoiding a LOG FULL Situation

Activate the automatic log backup (see Activating Automatic Log Backups). This guarantees regular backups of entries in the log area.

Check regularly that automatic log backup is activated. To do this, use the System Settings display in the Database Assistant, or the Log Area display in the Database Alert Monitor.

Also monitor the data area regularly. Follow the procedure described in Monitoring the Log Area.

See also:

DBA Planning Calendar, Scheduling Concept

Concepts of the Database System, Regular Administration Tasks, Backing Up Log Entries