Monday, May 20, 2013

Monitoring Oracle tablespace quota with OpenNMS

Going beyond the normal application availability check

One interesting use of the OpenNMS JDBC poller is for extracting data from the Oracle administrative database tables, for example tracking tablespace quota usage to detect quota exhaustion, sudden usage peaks and graph usage over time.

Graph of quota usage for user [redacted] on tablespace DAT.
Notice the cleaning operation running at 3.30 AM
Tablespace quotas is a feature present in the Oracle database that allows the DBA to set a limit on the amount of storage that any given user can consume on a specific tablespace. This allows the DBA to share tablespaces across users yet still be able to policy users into predefined usage boundaries. When a user consumes all its quota it can no longer store data, but it can delete it, thus allowing self-recovery.