ACK@Edge is a cloud-managed solution that is provided by Container Service for Kubernetes (ACK) to implement collaborative cloud-edge computing. This topic lists the latest changes to ACK@Edge of Kubernetes 1.16.

Kubernetes Core

The following describes the changes made to ACK@Edge of Kubernetes 1.16 in edge computing scenarios:
  • Fixes the issue that kubelet fails to start when more than four records are stored in the cpuacct.stat file of a node.
  • Kube-proxy supports the IP Virtual Server (IPVS) mode.
  • You can use kubelet to configure the internal IP address of a node by specifying the name of a network interface controller (NIC).

For more information about the release notes on ACK, see Kubernetes 1.16 release notes.

Autonomy of edge nodes

ACK@Edge of Kubernetes 1.16 enhances the stability of edge node autonomy. The following lists the major changes:
  • If the cached data is lost, clients receive the HTTP status code 404 instead of an empty string.
  • The directory that is used to store the certificate of edge-hub changes from /etc/kubernetes/edge-hub to /var/lib/edge-hub.
  • The certificate name of edge-hub changes from edge-hub.kubeconfig to edge-hub.conf, bootstrap-edge-hub-current.conf --> bootstrap-hub.conf.
  • An interface is added for prometheus metrics.
  • The performance of iptables is improved. iptables notrack is added for IP addresses 127.0.0.1:10261 and 169.254.2.1:10261.

For more information, see Autonomy of edge nodes.

Cloud-edge tunnels

ACK@Edge of Kubernetes 1.16 optimizes the performance of cloud-edge tunnels. The following lists the major changes:
  • The tunneling protocol changes from TCP to gRPC. Compared with TCP, the size of data transmitted over gRPC tunnels is reduced by 40%.
  • The edge-tunnel-agent component can automatically apply for and update certificates. This decouples the component from node certificates. In addition, the certificate of edge-tunnel-agent is stored in the /var/lib/edge-tunnel-agent/pki directory.
  • prometheus metrics are added.
  • The label that is used to deploy the pod for edge-tunnel-agent is changed to alibabacloud.com/is-edge-worker: "true".

For more information, see Cloud-edge tunneling.

Monitor components

ACK@Edge of Kubernetes 1.16 upgrades the metrics-server component and reinforces the security of this component. The following lists the major changes:
  • metrics-server is upgraded from V0.2.1 to V0.3.8.
  • ACK@Edge can be connected to Cloud Monitor by using tokens.

Cell-based management at the edge

ACK@Edge of Kubernetes 1.16 provides a new component yurt-app-manager and supports cell-based management at the edge. The following describes the main features of cell-based management at the edge:
  • Manage nodes by node pool.
  • Manage applications by using the UnitedDeployment controller.
  • Configure a Service topology to expose a Service to only the node or node pool where the Service is deployed.

For more information about cell-based management at the edge, see Overview of edge node pools.

Enhanced node pools

Enhanced node pools are supported by ACK@Edge of Kubernetes 1.16. An enhanced node pool has the following features:
  • Allows you to establish more stable and secure tunnels between the cloud and enhanced node pool.
  • Allows applications in on-premises networks at the edge to communicate with applications in the cloud by using container networking.

For more information, see Create an enhanced edge node pool.

Container runtimes

The following lists the major changes to container runtimes in ACK@Edge of Kubernetes 1.16:
  • The runC version of Advanced RISC Machine (ARM) and ARM64 is upgraded to 1.0.0-rc10.
  • Cgroupfs cgroup driver is changed to Systemd cgroup driver.

CNI plug-in

ACK@Edge of Kubernetes 1.16 enhances the stability of the Container Network Interface (CNI) plug-in. This fixes the issue that pods with the same name in different namespaces may be allocated invalid IP addresses.

Add edge nodes to a cluster

ACK@Edge of Kubernetes 1.16 optimizes the procedure of adding edge nodes to a cluster and adds some parameters. The following lists the major changes:
  • The procedure of adding edge nodes to a cluster is optimized and Classless Inter-Domain Routing (CIDR) conflict check is supported.
  • The number of IP addresses that can be assigned to nodes is configurable.
  • Parameters such as labels, nodeIface, annotations, and taints are added.
  • The Linux 5.4 kernel released by Ubuntu is supported.

For more information, see Add an edge node.

API changes

You can call the node pool API operations to manage edge node pools. For more information, see Node pools.