2021-04-28: Gitlab.com service outage from database failover event

Current Status

GitLab.com experienced a database failover from Patroni-03 to Patroni-07 resulting in an outage. Investigation into the root cause of the failover is underway. GitLab.com is back in a stable state.

Summary for CMOC notice / Exec summary:

1. Customer Impact: GitLab.com
2. Customer Impact Duration: 16:19 UTC - 16:29 UTC (10 minutes)
3. Current state: IncidentMitigated
4. Root cause: User initiated restart

Timeline

View recent production deployment and configuration events (internal only)

All times UTC.

2021-04-28

• 16:14:58 - shutdown of postgres on patroni-03 triggered, takes ~ 30 seconds to kill processes.

• 16:15:29 - a set of events from the logs:

• patroni.service: State 'stop-sigterm' timed out. Killing.

  • Apr 28 16:15:29 patroni-03-db-gprd systemd[1]: patroni.service: Main process exited, code=killed, status=9/KILL
  • Apr 28 16:15:29 patroni-03-db-gprd systemd[1]: Stopped Runners to orchestrate a high-availability PostgreSQL.
  • Apr 28 16:15:29 patroni-03-db-gprd systemd[1]: patroni.service: Unit entered failed state.
  • Apr 28 16:15:29 patroni-03-db-gprd systemd[1]: patroni.service: Failed with result 'signal'.

• 16:18 - @nnelson declares incident in Slack.

• 16:20 - patroni-07 takes over as leader

• 16:25 - services recover, saturation and error rates return to normal

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.

• Look into system logs to see what triggered the message noted in #4383 (comment 562930329). Was this human or system? Was it expected in either case?
• Better capture command history to logs: https://gitlab.com/gitlab-com/gl-infra/infrastructure/-/issues/13246

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Incident Review

Summary

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

Metrics

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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2. Do we have existing backlog items that would've prevented or greatly reduced the impact of this incident?
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3. Was this incident triggered by a change (deployment of code or change to infrastructure)? If yes, link the issue.
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Lessons Learned

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Guidelines

• Blameless RCA Guideline

Resources

1. If the Situation Zoom room was utilised, recording will be automatically uploaded to Incident room Google Drive folder (private)