Your cloud survived everything except the real world

You don't know what you've got till it's gone.

Great lyric, lousy data retention policy.

Amazon Web Services said last week that war damage to its Middle East infrastructure had permanently destroyed resources and data hosted exclusively in its now rather badly named Bahrain Availability Zones.

The damage overwhelmed the resilience built into the region.

Customers without copies elsewhere no longer had their data.

Sorry about that.

This may have surprised anyone who mistook cloud redundancy for an intrinsic guarantee of safety.

AWS is far from the only American operation to have suffered in the region: the US Navy has reportedly had its local maintenance and supply network badly mauled, with serious consequences for its operations.

If systems designed to withstand war cannot cope with sustained physical attacks, civilian bit barns have little chance.

The episode also underlines a familiar but easily neglected lesson: resilience within one cloud region is not the same thing as maintaining an independent backup elsewhere.

Physical destruction is not the only threat.

A major outage of the UK air traffic control system in September, which stranded hundreds of thousands of passengers and led to thousands of flight cancellations, was reportedly triggered by a military aircraft filing an incompatible flight plan.

Presumably Flight Lieutenant Bobby Tables has been reprimanded.

The apparent failure to validate the flight plan data was not the worst of it.