Slack Outage History

Slack experienced a 1-hour incident affecting file uploads, message edits, channel renames, channel creations, and third-party integrations, with users reporting inability to send files, GIFs, screenshots, and various app/messaging errors. The issue was caused by resource exhaustion and connectivity failures in internal infrastructure components responsible for processing background tasks. The incident was resolved by reverting a recent configuration change, which stabilized the affected systems and reduced error rates.

Slack experienced elevated error rates and latency affecting Enterprise Key Management (EKM) customers globally, causing issues with sending messages and loading channels. The incident impacted messaging, connectivity, files, and apps/integrations/APIs components. The service disruption lasted 12 minutes and was classified as a minor incident.

Slack customers using Enterprise Key Management (EKM) experienced issues with sending messages, loading channels, and delays with notifications and activity feeds due to problems with an upstream provider. The incident initially appeared resolved around 11:10 AM PDT but then recurred with elevated error rates and latency affecting EKM customers globally. Slack deployed cache configuration fixes and worked with their upstream provider who implemented a resolution, with error rates eventually returning to normal levels.

Slack users undergoing scheduled Grid Migrations experienced extended downtime lasting 5.5 hours, during which they were unable to access Slack until their migrations completed. The prolonged outage was caused by an issue with Job Queues that made the normally expected migration downtime significantly longer than usual. The incident affected connectivity for users in the migration process.

Slack workflows experienced failures where triggered workflows would not complete due to the first step failing to execute, primarily affecting EU users. The issue was caused by elevated latency in EU backend services, which led to workflow trigger attempts failing for a subset of users. A fix was deployed to address the backend latency issues, and the team monitored the environment until full service recovery was achieved.

Slack experienced a notification system issue where users were not receiving notification banners for thread replies, with some users also reporting login difficulties and message sending problems. The incident affected Slack's notification functionality for 3.5 hours. The issue was traced to a recent deployment, and Slack resolved it by rolling back the problematic deployment after successful testing in their test environments.

Slack experienced a minor service incident where some users, particularly those on Windows and Chrome, were unable to load Threads and received "Try Again" error messages. The connectivity issues affected the Threads feature specifically, preventing users from accessing threaded conversations. The incident lasted 2.5 hours with Slack investigating throughout the duration.

Slack experienced an issue where custom statuses set to expire at specific times were not automatically clearing as expected. The problem affected the messaging component and impacted users who relied on automatic status expiration functionality. The incident lasted 2 hours and was classified as a minor service disruption.

Slack experienced a messaging service incident where some users globally had trouble sending messages for 2.6 hours. The engineering team identified and deployed a fix by processing affected service PODs, which resulted in significant recovery across the platform. The incident was resolved after monitoring confirmed system stability was restored.

Slack experienced an 11.6-hour incident where users encountered intermittent issues with Slackbot responses and AI-powered features including Search Answers, Meeting Notes, Translation, and Workflows. The problem was initially caused by a third-party infrastructure issue, but secondary caching problems prolonged the outage even after the upstream provider resolved their issues. Slack resolved the incident by deploying configuration fixes and an emergency fix to address the caching issues, with significant recovery observed across all affected services.