2021-02-03 - Deployments blocked: "undefined method `map' for "---\n- gstg.plantuml.gitlab-static.net\n- staging.gitlab.com\n":String" error

Summary

post-deployment migration failed on Staging blocking deployments

Timeline

All times UTC.

2021-02-03

• 16:07 - A deployment to staging starts https://ops.gitlab.net/gitlab-com/gl-infra/deployer/-/pipelines/451724
• 16:10 - gstg-migrations fails with "undefined method `map' for "---\n- gstg.plantuml.gitlab-static.net\n- staging.gitlab.com\n":String" error". See here for the full log #3494 (comment 500723039)
• 16:27 - @mayra-cabrera declares incident in Slack.
• 17:13 - A fix is being prepared gitlab-org/gitlab!53272 (merged). It'll need to be deployed to staging to mitigate this incident.
• 20:44 - A deployment to staging with the fix starts https://ops.gitlab.net/gitlab-com/gl-infra/deployer/-/pipelines/452104
• 21:34 - Deployment to staging finishes successfully
• 21:35 - Deployment to canary starts
• 22:28 - Deployment to canary finishes successfully
• 23:32 - Deployment to prod starts
• 00:58 - Deployment to prod finishes

Corrective Actions

---

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

What were the root causes?

"5 Whys"

Incident Response Analysis

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

Post Incident Analysis

1. Did we have other events in the past with the same root cause?
   1. ...
2. Do we have existing backlog items that would've prevented or greatly reduced the impact of this incident?
   1. ...
3. Was this incident triggered by a change (deployment of code or change to infrastructure)? If yes, link the issue.
   1. ...

Lessons Learned

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)

Incident Review Stakeholders