An outage is any disruption in the ability of the database
solution to serve user applications. Outages can be classified in
two groups: unplanned outages and planned outages.
Unplanned outages
Examples of unplanned
outages include:
- The failure of one component of the system, including hardware
or software failure.
- Invalid administrative or user application actions such accidentally
dropping a table that is needed for business-critical transactions.
- Poor performance due to suboptimal configuration, or inadequate
hardware or software.
Planned outages
Examples of planned outages
include:
- Maintenance. Some maintenance activities require you to take a
complete outage; other maintenance activities can be performed without
stopping the database, but can adversely affect performance. The latter
is the most common type of planned outage.
- Upgrade. Upgrading your software or hardware can sometimes require
a partial or a full outage.
In discussions about availability, the focus is often
on disaster scenarios or component failures. However, to design a
robust high availability solution, you need to address all of these
types of outage.
DB2 Version 10.1 for Linux, UNIX, and Windows