Down day: Slack, GitHub, Walmart, AWS all suffer outages or other issues

Several large sites and services suffered issues and downtime today in what could be a range of possible coincidences or might share a common root cause.

Salesforce.com Inc.’s Slack led the pack, with some reports suggesting it was offline for as long as five hours, but it was not alone. Microsoft Corp.-owned GitHub, Walmart Inc., Peloton Inc., Comcast Cable Communications LLC’s Xfinity and Amazon Web Services Inc. are all reported to have had issues.

That AWS was on the list led some to suggest that AWS issues could have been to blame for the service disruption on other sites and services.

Slack first posted on a support thread at 9:25 a.m. EST that it was investigating reports that the team communications service was not loading for some users. By 12:07 p.m., a status update said that “we’re seeing signs of improvement.” The last update at 2:24 p.m. stated that “we’ve resolved the issue.”

“Thanks for bearing with us and we apologize for the disruption to your work day!” the final status concluded but did not provide any information as to what the issue was. Slack last suffered an outage on Jan. 4 that was about five hours long as well. Slack did not disclose what caused the outage in the previous case either.

Data Center Dynamics noted that it’s possible that Slack’s outage was caused by an unrelated software issue and just occurred at the same time as the AWS and Xfinity issues. That could be true, but it’s an interesting coincidence.

The AWS Service Health Dashboard did not show any outages during the time Slack was experiencing issues, but that has occurred before when there have been AWS issues. Reports to Downdetector show a different picture, with reports of issues with AWS starting to flow in from around 9 a.m. before peaking at 11:27 a.m.

Despite being owned by Microsoft, GitHub still has services hosted on AWS and suffered outages at around the same time, although the first reports of issues started at 4 a.m. Reports of Walmart having issues peaked at 11:33 a.m.

Other companies were reported to be having issues at around the same time. Users of Zoom Video Communications Inc., another AWS customer, reported issues as well, with the number peaking after 11 a.m.

Without any confirmation as to the cause of the outages by those affected, it’s impossible to know exactly what the cause was, but there is one common thread: AWS is the host in most if not all of the cases.

Photo: Slack