Hands-on Lab·Certified Kubernetes Administrator
Troubleshooting a Stalled Rollout
A Deployment that stops half way and keeps serving traffic while it does. This reads both conditions, shows the two ReplicaSets that make it safe, and undoes it.
Troubleshooting Guide 86 of 103 Intermediate
- Kubernetes1.36.4
- Runtimecontainerd 2.2.6
- CNICalico v3.32.1
- TimeAbout 16 min
- Reviewed26 August 2026
Written against the versions above. `progressDeadlineSeconds` is set to 30 here so the failure is watchable. The default is 600, which is ten minutes of looking like nothing is wrong.
| Server Name | IP Address | OS | Roles | CPU | RAM | HDD |
|---|---|---|---|---|---|---|
| CKA1001 | 192.168.0.175 | Ubuntu 26.04 LTS | Control Plane Node | 2 Core | 4 GB | 50 GB |
| CKA1001-NODE01 | 192.168.0.176 | Ubuntu 26.04 LTS | Worker Node | 2 Core | 4 GB | 50 GB |
| CKA1001-NODE02 | 192.168.0.177 | Ubuntu 26.04 LTS | Worker Node | 2 Core | 4 GB | 50 GB |
| CKA1001-NODE03 | 192.168.0.178 | Ubuntu 26.04 LTS | Worker Node | 2 Core | 4 GB | 50 GB |
Before you start
- guide 26 - the mechanism, before this covers it failing.
-
A healthy Deployment, with a short deadline so this is watchable
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Roll out an image that cannot start
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What the Deployment says about it
-
The two ReplicaSets
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Undo it