Computer outages

Published : Jun 07, 2017 12:32 IST

At the check-in counters at Heathrow Airport's Terminal 5 in London on May 28. Thousands of passengers faced a second day of travel disruption after an IT failure caused British Airways to cancel most of its flights.

At the check-in counters at Heathrow Airport's Terminal 5 in London on May 28. Thousands of passengers faced a second day of travel disruption after an IT failure caused British Airways to cancel most of its flights.

IT is a truth that should now be universally acknowledged, that everywhere in the world our lives are driven by computers—or more specifically by the workings of information and communication technology (ICT) and, therefore, the Internet. Our dependence on them is not just temporary or partial; it is continuous and overwhelming. People who actively use computers—desktops, laptops, tablets or mobile telephones—are not the only ones whose lives are driven by them and by Internet access. Increasingly, certainly in urban areas, almost all forms of transport, most forms of financial transactions and many forms of quotidian work and interaction are reliant on the underlying operations of computer systems. As “the Internet of things” quietly becomes more and more significant, the very gadgets that people use on a regular basis function on the basis of information collected, computed and transmitted in ways that are typically not even known to or grasped by the user.

All this has created new forms of dependency and vulnerability, which we do not fully recognise. The usual concerns that many people have about this domination of “smart” machines all around us relate to privacy, monitoring and surveillance, and, of course, the ever-present possibility of cyber fraud. These are certainly valid concerns. But the implications of a simple failure of a computer system—and outage or downtime—are somehow seen as less dire, probably because most people believe that such temporary collapses can be speedily rectified and dealt with, and that most computer systems have enough backup to resolve the ensuing problems quickly and relatively smoothly, without major disruption.

However, now it seems that such a belief in the fundamental resilience (if such a word can be used) and reliability of systems based in cyberspace are not justified and could even be touchingly naive. The latest example of the fragility of these systems was the collapse of the computer system of British Airways on May 27, which led to a complete shutdown of flights for a full day followed by huge numbers of cancellations and delays and chaos and confusion for several days thereafter.

According to British Airways, the computer system broke down because of a “power failure”—but surely that raises more questions than it answers. How could an international airline as large and established as British Airways not have a system of uninterrupted power supply, which is something even private individuals seek to ensure when they are dealing with data? Surely it would have had multiple servers in different locations? What about adequate backup, including on the “cloud”, which must be the most obvious item on any computer system checklist? And was there no system in place to deal with such emergency contingencies to minimise their adverse effects?

If none of this was apparently in place for British Airways, people would be justified in feeling concerned about many other computer systems that are assumed to have adequate protection, backup and contingency planning. What about banks, for example, and credit card companies that have apparently experienced various nightmarish hacks and other cyber threats that are intentionally played down by the media to prevent panic? What about military systems, which are increasingly reliant on software and computer programmes, which we do not lose sleep over because we assume that sufficient precautions have been taken to cover all possible contingencies, even unexpected ones?

In fact, what happened at British Airways is not entirely unusual at all. In August 2016, a power breakdown at Delta Airlines mission control in Atlanta caused massive disruptions, fight cancellations and delays. Apparently the switchgear that routes and distributes power failed; but significantly, in that case too the backup systems did not work, either because they were not in place or because some network operations that should have turned automatically to back up did not do so. The computer system was restored in six hours, although the knock-on effect of the disruption continued for several days because of the tightness of prior flight schedules.

Sometimes the problem stems from issues at data companies to which specific tasks are outsourced. Earlier this year, services at Britain’s National Health Service (NHS) were disrupted for several days because of a power outage at Capita data centre, which also affected various other companies that used them to provide online assistance and other computer services.

However, not all computer breakdowns are as damaging and disruptive; this clearly depends on the service being offered. The collapse of Amazon Web Services in early March involved a power breakdown for 11 hours, which meant not just major slowdowns but complete unavailability of more than a hundred large online retailers and major websites such as Amazon, Netflix and Reddit.

While this clearly caused significant losses, this may not have been as dramatic and disastrous. But the very simplicity of the cause of the problem makes one pause: apparently the entire breakdown was caused by a typo (see for more).

An employee engaged in routine maintenance to remove some of the smaller subsystem servers for billing incorrectly entered one wrong command, which brought down a large number of servers. That one human error could not be corrected immediately, and then the servers that had been brought down took much longer to be recovered than anyone had anticipated. (Indeed, it seems that some of these servers have still not been recovered.)

Simple human errors have been responsible for other breakdowns as well, so far with less adverse impact. The Internet start-up GitLab, which is a repository manager, was doing very well until it had a minor power outage that slowed down the system temporarily.

While trying to fix the system, a system administrator accidentally typed the command to delete the primary database. Meanwhile, the power outage had meant that the last backup was already six hours old—so some data was irretrievably lost, which for a repository is really bad news.

In these last examples, the point to note is not how bad the impact was (the final effect may not have been so terrible after all) but how minor and simple the error that caused it was. It underlines how ridiculously easy it apparently is to make entire systems come crashing down with just a minor, and only too human, mistake. It makes nonsense of the idea that these systems are meant to reduce the risk associated with the need for human intervention. In addition, obviously, the backup systems that will ensure that such things do not cause any real impact are simply not in place.

This may well be because maintaining such thorough and comprehensive backups that promise completely smooth and seamless transition when one system has failed is expensive and will reduce profitability. And in these days of cost cutting, such expensive features that may not have to be used often seem to CEOs to be unnecessary luxuries that companies can do without. Similarly, governments engaged in fiscal austerity are more inclined to cut corners in these crucial areas, especially if the probability of such a “black swan” event is rather low.

But that is all the more reason for us to be more worried than we are about our current state of vulnerability. It seems that attacks by cyberterrorists and hackers or manipulation of data by bad guys are not the only sources of possible collapse of the vast networks of computer systems that increasingly run our lives. It could just be some computer operator pressing the wrong key in a hurry—or on a bad hair day—that messes everything up.

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