2022-03-14: Gitlab.com issues with async jobs

Incident DRI

@donaldcook @mchacon3

Current Status

19:42 UTC - Root Cause has been identified and mitigated. We have reached a stable state for the site.

Performance of gitlab.com was degraded for 15 minutes between 17:11UTC-17:26UTC. The problem has been mitigated and service levels have returned to normal levels.

For customers believed to be affected by this incident, please subscribe to this issue or monitor our status page for further updates.

Summary for CMOC notice / Exec summary:

1. Customer Impact: Unable to load pages, failure of various API requests in the initial impact, which has subsided. There is ongoing investigation into async job queue growth.
2. Service Impact: ServiceAPI ServiceFrontend ServiceWeb
3. Impact Duration: 17:11 UTC - 17:26 UTC ( 15 minutes )
4. Root cause: TBD

Timeline

Recent Events (available internally only):

• Deployments
• Feature Flag Changes
• Infrastructure Configurations
• GCP Events (e.g. host failure)
• Gitlab.com Latest Updates

All times UTC.

2022-03-14

• 17:15 - Received first alerts from Pingdom and Blackbox about Gitlab.com being down.
• 17:23 - @mchacon3 declares incident in Slack.
• 17:44 - Seeing high traffic from a specific user. Blocking to see if that improves things. Confidential issue regarding specific users: https://gitlab.com/gitlab-com/gl-infra/production/-/issues/6587
• 17:52 - Site performance issues are back to expected levels. Current focus is on investigating async job issues.
• 17:57 - We are working on removing the jobs created by the abusive project, so we can alleviate the Sidekiq queue.
• 18:22 - Pipelines from user have been cancelled. Sidekick queue seems to be dropping.
• 18:45 - Sidekick queue is almost at pre-incident range. We're still monitoring.

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• Corrective action
• Investigation followup
• Confidential issue

Takeaways

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Corrective Actions

Corrective actions should be put here as soon as an incident is mitigated, ensure that all corrective actions mentioned in the notes below are included.

• See https://gitlab.com/gitlab-com/gl-infra/production/-/issues/6587#corrective-actions.

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Incident Review

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Customer Impact

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

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Incident Response Analysis

1. How was the incident detected?
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2. How could detection time be improved?
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3. How was the root cause diagnosed?
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4. How could time to diagnosis be improved?
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5. How did we reach the point where we knew how to mitigate the impact?
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6. How could time to mitigation be improved?
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7. What went well?
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Post Incident Analysis

1. Did we have other events in the past with the same root cause?
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What went well?

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Guidelines

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Resources

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