2020-08-12: 500 errors when logging in on staging.gitlab.com

Summary

500 errors when logging in on staging.gitlab.com

Logging in on Staging is failing with a 500 error. Sentry: https://sentry.gitlab.net/gitlab/staginggitlabcom/issues/1750485/events/32819261/

The error from Sentry is ActiveModel::MissingAttributeError: can't write unknown attribute target_type.

Potentially related to gitlab-org/gitlab!36198 (merged)

Timeline

All times UTC.

2020-08-12

• 03:21 - seanarnold declares incident in Slack using /incident declare command.
• 03:30 - engwan and seanarnold determine the failure is coming from a column added via a post-migration, which appear to be stuck behind other slower post-migrations
• 03:58 - seanarnold opened MRs to revert, and move migration for whichever approach we take.
• 04:27 - tkuah merged revert MR.

Click to expand or collapse the Incident Review section.

Incident Review

Summary

1. Service(s) affected:
2. Team attribution:
3. Minutes downtime or degradation:

Metrics

Customer Impact

1. Who was impacted by this incident? (i.e. external customers, internal customers)
2. What was the customer experience during the incident? (i.e. preventing them from doing X, incorrect display of Y, ...)
3. How many customers were affected?
4. If a precise customer impact number is unknown, what is the estimated potential impact?

Incident Response Analysis

1. How was the event detected?
2. How could detection time be improved?
3. How did we reach the point where we knew how to mitigate the impact?
4. How could time to mitigation be improved?

Post Incident Analysis

1. How was the root cause diagnosed?
2. How could time to diagnosis be improved?
3. Do we have an existing backlog item that would've prevented or greatly reduced the impact of this incident?
4. Was this incident triggered by a change (deployment of code or change to infrastructure. If yes, have you linked the issue which represents the change?)?

5 Whys

Lessons Learned

Corrective Actions

Guidelines

• Blameless RCA Guideline