2021-03-24: Shared Runner Managers 4, 6, and 7 not picking up jobs

Current Status

Three runner managers are not picking up jobs causing delayed job processing for a some users. We are investigating and working with upstream providers and applying a mitigation which can allow us to process backed up jobs.

Summary for CMOC notice / Exec summary:

1. Customer Impact: Shared Runners
2. Customer Impact Duration: 14:50 UTC - 17:36 UTC ( 170 )
3. Root cause: Newly created job runners were unreachable by the shared runner managers in a specific Google zone (us-east1-b). This was an upstream cloud provider networking issue.

We are investigating delays in job processing since 14:50 UTC

Timeline

View recent production deployment and configuration events (internal only)

All times UTC.

2021-03-24

• 16:32 - @steveazz declares incident in Slack.

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.

• Add fallback region for docker-machine executor
• Update the CI Runner Apdex thresholds

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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

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