2022-03-21: Job traces get lost in Staging
Incident DRI
Current Status
In staging, it was discovered that Job Traces disappeared roughly 2 minutes after a job completed.
Summary for CMOC notice / Exec summary:
- Customer Impact: n/a
- Service Impact: ServiceGitLab Rails
- Impact Duration: 2022-03-14 - 2022-03-21
- Root cause: RootCauseSoftware-Change
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
- Feature Flag removal for
staging
occurs - Overall Tracking issue: gitlab-org/gitlab#353995 (closed)
2022-03-21
-
10:57
- @furkanayhan declares incident in Slack. -
12:24
- Incident escalated due to uncertainty that this is a problem with a configuration or software -
14:20
- Investigation via rails console in staging reveals this is related to the Geo feature - which is only enabled staging -
14:20
- Feature flag is reversed, and testing proved job traces remained available as desired (uploaded to object storage) -
15:00
- Revert of feature is created and labeled for auto-deploy - gitlab-org/gitlab!83302 (merged) -
16:20
- Severity of incident lowered as this only impacts staging
Create related issues
Use the following links to create related issues to this incident if additional work needs to be completed after it is resolved:
- Support contact request
- Corrective action
- Investigation followup
- Confidential issue
- QA investigation
- Infradev
Takeaways
- The discrepancy of Geo being enabled on Staging and not production led to a suprising find, a whopping 7 days after the feature flag was modified
- QA testing was unable to detect this style of issue
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.
- ...
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Incident Review
-
Ensure that the exec summary is completed at the top of the incident issue, the timeline is updated and relevant graphs are included in the summary -
If there are any corrective action items mentioned in the notes on the incident, ensure they are listed in the "Corrective Action" section -
Fill out relevant sections below or link to the meeting review notes that cover these topics
Customer Impact
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Who was impacted by this incident? (i.e. external customers, internal customers)
- internal only
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What was the customer experience during the incident? (i.e. preventing them from doing X, incorrect display of Y, ...)
- Job traces would disappear a few minutes after a job has completed, regardless of the success of said job.
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How many customers were affected?
- All CI jobs associated with the staging environment
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If a precise customer impact number is unknown, what is the estimated impact (number and ratio of failed requests, amount of traffic drop, ...)?
- n/a
What were the root causes?
Incident Response Analysis
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How was the incident detected?
- Engineering
-
How could detection time be improved?
- QA tests should've been able to pick up this issue.
-
How was the root cause diagnosed?
- A targetted investigation of artifact uploads via the rails console, methods are documented below
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How could time to diagnosis be improved?
- n/a
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How did we reach the point where we knew how to mitigate the impact?
- This was part of the investigation
-
How could time to mitigation be improved?
- n/a
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What went well?
- Collaboration among Engineering and troubleshooting via the console
Post Incident Analysis
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Did we have other events in the past with the same root cause?
- No
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Do we have existing backlog items that would've prevented or greatly reduced the impact of this incident?
- No
- Was this incident triggered by a change (deployment of code or change to infrastructure)? If yes, link the issue.
What went well?
- ...
Guidelines
Resources
- If the Situation Zoom room was utilised, recording will be automatically uploaded to Incident room Google Drive folder (private)