Incident Report

Summary

On 24 July 2023 at 07:50, following a Google Classroom iOS app update, the app would not load properly if users attempted to access any course page that had attached materials for a duration of 1 day, 20 hours, 25 minutes. During the disruption, users were able to access course pages by uninstalling and reinstalling the Classroom iOS app.

Root Cause

The root cause has been identified as a bug, triggered by an update released for Classroom iOS, that caused an issue with the local database migration. This caused the iOS app to not load properly when users attempted to access course pages with attached materials, as the migration was specific to the materials configuration.

Remediation and Prevention

Google engineers were alerted to the issue via internal monitoring on 24 July 2023 at 07:50 US/Pacific and immediately started an investigation. Google engineers reproduced the issue, identified the trigger as a failed database migration, and paused the auto update. This prevented any further disruption. An app update with a fix was released for the Classroom iOS app, thereby resolving the issue on 26 July 2023 at 04:15 US/Pacific. Users who had already updated to the problematic app version were advised to either uninstall and reinstall or update the app to the version with the fix.

Google is committed to preventing recurrence by implementing the following action items:

• Implement additional pre-release migration and application testing plans to validate app stability

Mini Incident Report

We apologize for the inconvenience this service disruption/outage may have caused. We would like to provide some information about this incident below. Please note, this information is based on our best knowledge at the time of posting and is subject to change as our investigation continues. If you have experienced impact outside of what is listed below, please reach out to Google Workspace Support using the help article https://support.google.com/a/answer/1047213.

(All Times US/Pacific)

Incident Start: 24 July 2023 at 07:50

Incident End: 26 July 2023 at 04:15

Duration: 1 day, 20 hours, 25 minutes

Affected Services and Features:

Google Classroom

Regions/Zones: Global

Description:

Google Classroom experienced an issue where the Classroom iOS app crashed for users when they attempted to access any course page following an update of the app. From preliminary analysis, the root cause was an issue that caused a migration of the app's local database to fail, resulting in crashes for all users upgrading the application.

Our engineers withdrew the problematic app update and released a new app update with the fix. Affected users should update their apps to the latest version available on the iOS app store for the fix.

Customer Impact:

• Less than two percent of Daily Active Users for Classroom iOS experienced app crashes when they attempted to access any course page following an update of the app.

• Users that freshly installed the Classroom iOS app were not impacted by the issue.

The issue with Classroom has been resolved for all affected users as of Wednesday, 2023-07-26 04:15 US/Pacific.

We thank you for your patience while we worked on resolving the issue.

Description

Mitigation work is currently underway by our engineering team. We do not have an ETA for mitigation at this point. We will provide more information by Wednesday, 2023-07-26 03:30 US/Pacific.

Diagnosis

When a user updates (not a fresh install) their Classroom iOS app, the app will crash when attempting to access any Course page.

Workaround

Uninstalling & reinstalling the application will resolve the crash.