Repository: kubernetes
Issue: "Error syncing pod, skipping" err="rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial unix /run/containerd/containerd.sock: connect: connection refused\"" pod="" podUID=""
Labels: kind/bug,needs-sig,needs-triage

### What happened?

Pod has been terminating, error: "Error syncing pod, skipping" err="rpc error: code = Unavailable desc = connection error: desc = \"transport: Error while dialing: dial unix /run/containerd/containerd.sock: connect: connection refused\"" pod="" podUID=""， Actually, containerd is normal

### What did you expect to happen?

Pod pulled up normally

### How can we reproduce it (as minimally and precisely as possible)?

Dec  5 23: Upgrade caas from 53 onwards
Dec  5 23: 56 Node Restart
Dec 5 23:56:52 containerd starts after power on
Since the start of the kubelet process on Dec 6 00:00:23, it has not been restarted yet. It should be at this point in time that the kubelet was upgraded
Dec 6 00:00:06 Crittl Check the start and run time of the container process for nbidataserver (cinit process inside the container)
Dec 6 00:01:16 ps Check the startup time of the business process. The probe may not be ready for a short period of time before starting, and the kubelet may only sync after reaching certain conditions 
Dec 6 00:01:37 nbidataservice updataPodContainerResources first reported failure containerdsock connection rejected and kept reporting errors afterwards
Dec 6 00:01:38 containerd upgraded and started up until now



Latest progress: This issue is caused by enabling the InPlacePodVerticalScaling feature
Event replay:
Event 1:2024-12-24 22:41:33 Machine Power On/Off
Event 2:2024-12-24 22:47:53 kubelet starts to start, Pod starts to be pulled up
Event 3:2024-12-24 22:49:03 containerd starts
Event 4:2024-12-24 22:49:04 kubelet started pulling up smauthservice, but received an error message "server is not initialized yet" when accessing containerd. After containerd started, smauthservice started normally.
Event 5:2024-12-24 22:54:12: The upgrade of smauthservice started, and the Kubernetes control plane set the pod smauthservice to Terminating state, which has been consistent until now.
Cause analysis:
1. The kubelet caches real pod information (also known as pod cache), which is synchronized from containerd by PLEG (PodLifecycle Event Generator) coroutine timing. PLEG itself also caches the real pod state (known as PLEG cache). If PLEG detects a difference between the real container state and its own cache, it will synchronize the real pod information to the pod cache.
2. After enabling the InPlacePodVerticalScaling feature, during the pod startup phase, if the pod is expanding, kubelet will query the real pod status from containerd and update the pod cache directly without PLEG. At this time, because containerd cannot access it, unknown status will be saved to the pod cache (Event 4). However, PLEG will not update the pod cache again because the actual pod status is no different from its own cache.
3. Later on, when upgrading the pod, the coroutine for handling pod deletion needed to retrieve the actual pod state from the pod cache for tuning. However, an unknown state was obtained, so the deletion of the pod was stopped and the pod remained in Terminating (Event 5).


### Anything else we need to know?

_No response_

### Kubernetes version

<details>

```console
$ kubectl version
# paste output here
```
1.28.1
</details>


### Cloud provider

<details>
na
</details>


### OS version

<details>

```console
# On Linux:
$ cat /etc/os-release
# paste output here
$ uname -a
# paste output here

# On Windows:
C:\> wmic os get Caption, Version, BuildNumber, OSArchitecture
# paste output here
```

</details>


### Install tools

<details>

</details>


### Container runtime (CRI) and version (if applicable)

<details>

</details>


### Related plugins (CNI, CSI, ...) and versions (if applicable)

<details>

</details>