Data Centers
More rarely, a correlated failure might spread its effects across sites.
It means that data centers in different geographic locations can be impacted by the same event,
causing data loss or unavailability. Examples of such correlated failures include the following
items:
- Power grid failures
- Internet or backbone failures (cut cables, peering disputes)
- Global internet worm
- Organizational failures (insolvency, dissolution)
- Social unrest (wars, riots, terrorism)
These events occur infrequently, but as they occur they might affect the availability of multiple
sites across a geographic area. While it is not possible to defend against every contingency, the
correlation between site failures can be greatly reduced by appropriate selection of your sites.
Tip: Use sites on different power grids, and use different internet backbones and
providers at each site.