Interconnecting CCE with CCI

Overview

This section describes how you can use the bursting add-on in a CCE cluster to quickly schedule pods to CCI.

The bursting add-on functions as a virtual kubelet to connect Kubernetes clusters to APIs of other platforms. This add-on is mainly used to extend Kubernetes APIs to serverless container services such as Huawei Cloud CCI.

With this add-on, you can schedule Deployments, StatefulSets, jobs, and CronJobs running in CCE clusters to CCI during peak hours. In this way, you can reduce consumption caused by cluster scaling.

Prerequisites

Before using the add-on, go to the CCI console to grant CCI with the permissions to use CCE.

Constraints

• Only CCE standard and CCE Turbo clusters that use the VPC network model are supported.
• When the CCE Cloud Bursting Engine for CCI add-on is used with CCI 1.0, the Landing Zone scenario is not supported.
• After the add-on is installed, a namespace named cce-burst-{cluster-ID} will be created in CCI and managed by the add-on. Do not use this namespace when manually creating pods in CCI.
• The bursting add-on earlier than v1.5.37 cannot be used in clusters of the Arm architecture. Add-on instances will not be deployed on Arm nodes, if any, running in the cluster.
• The subnet where the cluster is located cannot overlap with 10.247.0.0/16, or the subnet conflicts with the Service CIDR block in the CCI namespace.
• Currently, Volcano Scheduler of 1.17.10 or earlier cannot be used to schedule pods with cloud storage volumes mounted to CCI.
• The following table lists the Kubernetes versions and their restrictions. The restrictions of a later version also apply to earlier versions.

  Kubernetes Version	Restrictions
  1.34	PodLevelResources is not supported. RelaxedDNSSearchValidation is not supported. RelaxedEnvironmentVariableValidation is not supported. AppArmor configurations in SecurityContext are not supported. CCI does not support the VolumeAttributesClass API. When using PVCs in auto scaling scenarios, do not configure the VolumeAttributesClassName field of the PVCs (in other words, do not bind the PVCs to the VolumeAttributesClass object), or the configuration will not be applied in CCI.
  1.33	InPlacePodVerticalScaling is not supported.
  1.32	PodLifecycleSleepAction is not supported.
  1.31	DynamicResourceAllocation is not supported.

Installing the Add-on

1. Log in to the CCE console.
2. Click the name of the target CCE cluster to go to the cluster console.
3. In the navigation pane, choose Add-ons.
4. Select the CCE Cloud Bursting Engine for CCI add-on and click Install.
5. Configure the add-on parameters.

   

   Table 1 Add-on parameters

   Parameter	Description
   Version	Add-on version.
   Specifications	Number of pods required for running the add-on. If you select Preset, you can select Single or HA. If you select Custom, you can modify the number of replicas, vCPUs, and memory of each add-on component as required. NOTE: The bursting add-on 1.5.2 or later uses more node resources. You need to reserve sufficient pods before upgrading the add-on. Single (only one pod for the add-on): There must be a node that has at least seven schedulable pods. If Networking is enabled, eight schedulable pods are required. HA (two pods for the add-on): There must be two nodes, each of which must have at least seven schedulable pods, a total of 14 schedulable pods. If Networking is enabled, eight schedulable pods are required on each node, a total of 16 schedulable pods. The resource usage of the add-on varies depending on the workloads scaled to CCI. The pods, secrets, ConfigMaps, PVs, and PVCs requested by the services occupy VM resources. You are advised to evaluate the service usage and apply for VMs based on the following specifications: For 1,000 pods and 1,000 ConfigMaps (300 KB), nodes with 2 vCPUs and 4-GiB memory are recommended. For 2,000 pods and 2,000 ConfigMaps, nodes with 4 vCPUs and 8-GiB memory are recommended. For 4,000 pods and 4,000 ConfigMaps, nodes with 8 vCPUs and 16-GiB memory are recommended.
   Networking	If this option is enabled, pods in the CCE cluster can communicate with pods in CCI through Services. The component proxy will be automatically deployed upon add-on installation.

Creating the Workload to Be Scheduled

1. Log in to the CCE console.
2. Click the name of the target CCE cluster to go to the cluster console.
3. In the navigation pane, choose Workloads.
4. Click Create Workload. For details, see Creating a Workload.
5. Specify basic information. Set Burst to CCI to Force scheduling.

   

6. Configure the container parameters.
7. Click Create Workload.
8. On the Workloads page, click the name of the created workload to go to the workload details page.
9. View the node where the workload is running. If the workload is running on a CCI node, it has been scheduled to CCI.

Uninstalling the Add-on

1. Log in to the CCE console.
2. Click the name of the target CCE cluster to go to the cluster console.
3. In the navigation pane, choose Add-ons.
4. Select the CCE Cloud Bursting Engine for CCI add-on and click Uninstall.

   

   Table 2 Special scenarios for uninstalling the add-on

   Scenario	Symptom	Description
   There are no nodes in the CCE cluster that the bursting add-on needs to be uninstalled from.	Failed to uninstall the bursting add-on.	If the bursting add-on is uninstalled from the cluster, a job for clearing resources will be started in the cluster. To ensure that the job can be started, there must be at least one schedulable node in the cluster.