Microsoft Corp.’s Azure and other leading cloud platforms have safeguards against outages, but the risk of downtime can never be eliminated completely, because a disruption may be caused by human error, a power cut or any number of other factors.

To help Azure customers better deal with such situations, Microsoft on Thursday introduced Availability Zones. It’s a feature that rivals such as Amazon Web Services Inc. and Google Cloud Platform have provided for quite some time. The terminology differs across platforms, but the basic concept is the same: An Availability Zone consists of multiple isolated hosting sites located in the same geographic region for redundancy purposes.

When one facility goes down, affected workloads can simply fail over to another nearby. This arrangement doesn’t offer much protection against major regional disruptions such hurricanes, but addresses almost everything else. That’s why it’s key to business continuity planning for many companies that rely on public clouds.

Availability Zones are particularly handy when failing over to a data center in a different geographic region isn’t practical. The biggest consideration is usually latency. For example, a company using Azure to process real-time sensory data from a manufacturing plant may wish to avoid the delay of sending the information to another part of the country for analysis.

On Microsoft’s end, creating the Availability Zones will entail a major infrastructure expansion. The company so far has added extra cloud locations in Virginia and the Netherlands as part of the initiative. It plans to bring additional facilities online in the U.S., Europe and Asia by the end of the year.

Microsoft announced the move on the same morning it marked the completion of an equally ambitious infrastructure project. Together with Facebook Inc., the company has financed the construction of a submarine communications cable stretching over 4,000 miles from Virginia Beach to Bilbao, Spain. The link weighs 10.2 million pounds and can transmit up to 160 terabits of data per second, enough to stream 71 million high-definition videos simultaneously.

Image: Microsoft