Facebook's longest outage yet was flagged by Downdetector. Here's how it works

As Facebook, Instagram and WhatsApp went dark on Monday night, Downdetector, surveying the internet for online service status information, let the users know that they are not alone in experiencing the outage and that it certainly was not a result of a poor WiFi connection or broken internet. Downdetector, which analyses tens of millions of daily problem reports, makes people everywhere aware that the rest of the world is experiencing a similar issue as well. Throughout Monday night, the website's servers stood on a strict vigil and kept updating in real-time the status of the Facebook outage, which lasted for nearly six hours before the services started gradually getting back online.

With Facebook, Instagram, and WhatsApp now ‘entirely’ back online, here's a brief review of how the Downdetector service, the world's most popular platform for online service status information, works.

Downdetector, according to its official website, offers real-time status information for more than 6,000 services across 45 websites representing 45 countries. When a service provider’s customers are experiencing problems, Downdetector aggregates and analyses this data to determine the potential nature of the issue and then works to alert both the company and community of possible issues.

For ease of access to users, Downdetector usually marks a certain website with a red exclamation mark icon if a large volume of users reports that are facing potential problems with the said website. If there are no such reports, the icon will be absent. Moreover, enterprise users can also directly communicate with their customers via their company's page on Downdetector. In the example image above, the Webco team has sent a message for its users regretting the inconvenience caused due to the snag.

Also Read | Why Facebook, Instagram and WhatsApp were all down. Explained

To make the reporting process easier, Downdetector has a ‘problem report button’, with which users can submit a problem report about a particular website to Downdetector, choosing from a predefined list of problem indicators about the type of issue they are experiencing.

The most significant part of the page is the live outage map, which shows the ‘spikes’ in reports over time; it helps users gauge the kind of response the website is getting across the world. If there are a lot of spikes corresponding to the timestamps, like in the image above, it means users all over the world are experiencing similar problems with the website. Downdetector also has a daily historical view of problem reports compared to the baseline volume.

How Downdetector collects status information

As more and more users submit problem reports directly on a company status page on Downdetector, along with an indicator of the type of problem they are experiencing, the tracking service gathers data through Twitter and uses ‘sentiment analysis’ to detect issues for a given company and its location. It also looks at other key indicators from across the web to determine if an extraordinary volume of users is having issues with a monitored company or service.

How Downdetector determines if there’s an incident

According to Downdetector, a small number of users reporting a problem does not constitute a large-scale incident. To make sure that incidents are correctly represented, the website calculates “a baseline volume of typical problem reports for each service monitored”, based on the average number of reports for that given time of day, measured over the previous year. Downdetector only reports an incident when the number of problem reports is significantly higher than the baseline.

“Downdetector only accepts the first report for a specific company from a single user. Subsequent information about the issue is collected but is not counted as a new problem report,” as per the website.