Slack outage: Slack gets knocked down, but gets up again

Woman angry at computer

Slack suffered a worldwide outage yesterday lasting three and a half hours, forcing office staff across the globe to resort to email, or even talking to colleagues in person.

The communication tool, which counted six million daily users in 2017 warned that "all workspaces are experiencing difficulties".

Downdetector, which tracks outages with popular applications, showed the US, UK and mainland Europe were having the most difficulty.

Naturally, people responded to the issue with a sense of calm equanimity online.

The issue began at 2.33pm BST, with Slack posting the following update to its status page an hour later: "We are continuing to work on fixing the connection problems that have been impacting folks. We hope to have the issue fully resolved as soon as possible."

By 5.49pm Slack had resolved the issue, writing on its status update page: "We're happy to report that workspaces should be able to connect again, as we've isolated the problem."

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What that problem was remains a mystery, but IT Pro has asked the company about the root cause, and will update this article if and when we hear back.

The firm runs its platform on top of Amazon Web Services (AWS) - EC2 instances for basic compute, S3 for user uploads and static assets, Elastic Load Balancing to distribute workloads across EC2, and EBS for overnight backups.

"As a company, our business is integral to our customers' daily lives," Richard Crowley, Slack's director of operations, is quoted as saying on AWS's website.

"So in our customers' eyes, our security controls and ability to deliver a reliable service become incredibly important, and it's a responsibility we take incredibly seriously."

Slack debuted new developer tools last month designed to allow them to code and test their own Slack apps within the Slack platform, as well as coming with built-in integrations for third-party apps popular with coders; Asana, Bitbucket, HubSpot, Zendesk and Jira.

The collaboration tool isn't the only service to experience issues recently, with Office 365 dropping offline for UK users earlier this month, as well as back in April.