Selecting a Network Model

CCE uses proprietary, high-performance container networking add-ons to support the tunnel network and VPC network models.

Caution

After a cluster is created, the network model cannot be changed. Exercise caution when selecting a network model.

  • Tunnel network: The container network is an overlay tunnel network on top of a VPC network and uses the VXLAN technology. This network model is applicable when there is no high requirements on performance. VXLAN encapsulates Ethernet packets as UDP packets for tunnel transmission. Though at some cost of performance, the tunnel encapsulation enables higher interoperability and compatibility with advanced features (such as network policy-based isolation), meeting the requirements of most applications.

    **Figure 1** Container tunnel network

    Figure 1 Container tunnel network

  • VPC network: The container network uses VPC routing to integrate with the underlying network. This network model is applicable to performance-intensive scenarios. The maximum number of nodes allowed in a cluster depends on the route quota in a VPC network. Each node is assigned a CIDR block of a fixed size. VPC networks are free from tunnel encapsulation overhead and outperform container tunnel networks. In addition, as VPC routing includes routes to node IP addresses and container network segment, container pods in the cluster can be directly accessed from outside the cluster.

    **Figure 2** VPC network

    Figure 2 VPC network

The following table lists the differences between the network models.

Table 1 Network model comparison

Dimension

Tunnel Network

VPC Network

Application scenarios

  • Low requirements on performance: As the container tunnel network requires additional VXLAN tunnel encapsulation, it has about 5% to 15% of performance loss when compared with the other two container network models. Therefore, the container tunnel network applies to the scenarios that do not have high performance requirements, such as web applications, and middle-end and back-end services with a small number of access requests.

  • Large-scale networking: Different from the VPC network that is limited by the VPC route quota, the container tunnel network does not have any restriction on the infrastructure. In addition, the container tunnel network controls the broadcast domain to the node level. The container tunnel network supports a maximum of 2000 nodes.

  • High performance requirements: As no tunnel encapsulation is required, the VPC network model delivers the performance close to that of a VPC network when compared with the container tunnel network model. Therefore, the VPC network model applies to scenarios that have high requirements on performance, such as AI computing and big data computing.

  • Small- and medium-scale networks: Due to the limitation on VPC routing tables, it is recommended that the number of nodes in a cluster be less than or equal to 1000.

Core technology

OVS

IPvlan and VPC route

Applicable clusters

CCE standard cluster

CCE standard cluster

Container network isolation

Kubernetes native NetworkPolicy for pods

No

Interconnecting pods to a load balancer

Interconnected through a NodePort

Interconnected through a NodePort

Managing container IP addresses

  • Separate container CIDR blocks needed

  • Container CIDR blocks divided by node and dynamically added after being allocated

  • Separate container CIDR blocks needed

  • Container CIDR blocks divided by node and statically allocated (the allocated CIDR blocks cannot be changed after a node is created)

Network performance

Performance loss due to VXLAN encapsulation

No tunnel encapsulation, and cross-node traffic forwarded through VPC routers (The performance is so good that is comparable to that of the host network, but there is a loss caused by NAT.)

Networking scale

A maximum of 2000 nodes are supported.

Suitable for small- and medium-scale networks due to the limitation on VPC routing tables. It is recommended that the number of nodes be less than or equal to 1000.

Each time a node is added to the cluster, a route is added to the VPC routing tables. Evaluate the cluster scale that is limited by the VPC routing tables before creating the cluster.

Important

  1. The scale of a cluster that uses the VPC network model is limited by the custom routes of the VPC. Therefore, you need to estimate the number of required nodes before creating a cluster.

  2. By default, VPC routing network supports direct communication between containers and hosts in the same VPC. If a peering connection policy is configured between the VPC and another VPC, the containers can directly communicate with hosts on the peer VPC. In addition, in hybrid networking scenarios such as Direct Connect and VPN, communication between containers and hosts on the peer end can also be achieved with proper planning.

last updated: 2024-11-08 14:16 UTC - commit: 7c478af3470092ad91013d02b08e29c6a61c275d