2021-09-02: Prometheus not connected to any Alertmanagers
Current Status
Each of our GKE clusters has 2 prometheus pods for scraping prometheus targets in that cluster. One of those GKE clusters (gprd-us-east1-c
) lost one of its 2 pods, and it took 20 minutes for its replacement pod to reach a healthy state.
Timeline
View recent production deployment and configuration events / gcp events (internal only)
All times UTC.
2021-09-02
-
16:44
- 1 of the 2 prometheus server pods dies in GKE clusterus-east1-c
. A new pod is provisioned on a new k8s node, but it takes roughly 20 minutes for it to reach a healthy state. During this time, only the 1 surviving prometheus server is scraping targets in this GKE cluster and providing metrics. -
16:57
- @msmiley declares incident in Slack. -
17:05
- The replacement pod reaches a healthy state. Redundancy is restored.
This screenshot illustrates the timeline, showing when the old pod failed and when the new pod reached a healthy state:
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
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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)
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What was the customer experience during the incident? (i.e. preventing them from doing X, incorrect display of Y, ...)
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How many customers were affected?
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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, ...)?
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What were the root causes?
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Incident Response Analysis
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How was the incident detected?
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How could detection time be improved?
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How was the root cause diagnosed?
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How could time to diagnosis be improved?
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How did we reach the point where we knew how to mitigate the impact?
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How could time to mitigation be improved?
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What went well?
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Post Incident Analysis
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Did we have other events in the past with the same root cause?
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Do we have existing backlog items that would've prevented or greatly reduced the impact of this incident?
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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
Resources
- If the Situation Zoom room was utilised, recording will be automatically uploaded to Incident room Google Drive folder (private)