Master nodes

Modifying the security group of a node in a cluster

The master node may be unavailable.

Restore the security group by referring to Buying a CCE Cluster and allow traffic from the security group to pass through.

Letting the node expire or destroying the node

The master node will be unavailable.

This operation cannot be undone.

Reinstalling the OS

Components on the master node will be deleted.

This operation cannot be undone.

Upgrading components on the master or etcd node

The cluster may be unavailable.

Roll back to the original version.

Deleting or formatting core directory data such as /etc/kubernetes on the node

The master node will become unavailable.

This operation cannot be undone.

Changing the node IP address

The master node will become unavailable.

Change the IP address back to the original one.

Modifying parameters of core components (such as etcd, kube-apiserver, and docker)

The master node may be unavailable.

Restore the parameter settings to the recommended values. For details, see Configuring Kubernetes Parameters.

Replacing the master or etcd certificate

The cluster may become unavailable.

This operation cannot be undone.

Worker nodes

Modifying the security group of a node in a cluster

The node may be unavailable.

Restore the security group by referring to Buying a CCE Cluster and allow traffic from the security group to pass through.

Deleting the node

The node will become unavailable.

This operation cannot be undone.

Reinstalling the OS

Node components are deleted, and the node becomes unavailable.

Reset the node. For details, see Resetting a Node.

Upgrading the node kernel

The node may be unavailable or the network may be abnormal.

If the OS is EulerOS 2.2, restore the node or network connectivity by referring to What Can I Do If the Container Network Becomes Unavailable After yum update Is Used to Upgrade the OS?

If the OS is not EulerOS 2.2, you can reset the node. For details, see Resetting a Node.

Changing the node IP address

The node will become unavailable.

Change the IP address back to the original one.

Modifying parameters of core components (such as kubelet and kube-proxy)

The node may become unavailable, and components may be insecure if security-related configurations are modified.

Restore the parameter settings to the recommended values. For details, see Configuring Kubernetes Parameters.

Modifying OS configuration

The node may be unavailable.

Restore the configuration items or reset the node. For details, see Resetting a Node.

Deleting the opt directory, /var/paas directory, or a data disk

The node will become unready.

You can reset the node. For details, see Resetting a Node.

Modifying the node directory permission and the container directory permission

The permissions will be abnormal.

You are not advised to modify the permissions. Restore the permissions if they are modified.

Formatting or partitioning disks on cluster nodes

The node will become unready.

You can reset the node. For details, see Resetting a Node.

Installing other software on nodes

This may cause exceptions on Kubernetes components installed on the node, and make the node unavailable.

Uninstall the software that has been installed and restore or reset the node. For details, see Resetting a Node.

Changing the value of the kernel parameter net.ipv4.ip_forward to 0

The network becomes inaccessible.

Change the value to 1.

Changing the value of the kernel parameter net.ipv4.tcp_tw_recycle to 1.

The NAT service becomes abnormal.

Change the value to 0.

Not configuring the node security group to allow UDP packets to pass through port 53 of the container CIDR block

The DNS in the cluster cannot work properly.

Restore the security group by referring to Buying a CCE Cluster and allow traffic from the security group to pass through.

Creating a custom listener on the ELB console for the load balancer managed by CCE

The modified items are reset by CCE or the ingress is faulty.

Use the YAML file of the Service to automatically create a listener.

Binding a user-defined backend on the ELB console to the load balancer managed by CCE.

Do not manually bind any backend.

Changing the ELB certificate on the ELB console for the load balancer managed by CCE.

Use the YAML file of the ingress to automatically manage certificates.

Changing the listener name on the ELB console for the ELB listener managed by CCE.

Do not change the name of the ELB listener managed by CCE.

Changing the description of load balancers, listeners, and forwarding policies managed by CCE on the ELB console.

Do not modify the description of load balancers, listeners, or forwarding policies managed by CCE.

Delete CRD resources of network-attachment-definitions of default-network.

The container network is disconnected, or the cluster fails to be deleted.

If the resources are deleted by mistake, use the correct configurations to create the default-network resources.

Deleting the /tmp/ccs-log-collector/pos directory on the host machine

Logs are collected repeatedly.

None

Deleting the /tmp/ccs-log-collector/buffer directory of the host machine

Logs are lost.

None

Manually unmounting an EVS disk on the console

An I/O error is reported when the pod data is being written into the disk.

Delete the mount path from the node and schedule the pod again.

The file in the pod records the location where files are to be collected.

Unmounting the disk mount path on the node

Pod data is written into a local disk.

Remount the corresponding path to the pod.

The buffer contains log cache files to be consumed.

Operating EVS disks on the node

Pod data is written into a local disk.

None

None