Communication between containers flannel and calico comparison

1.calico principle ：

The following figure describes the process from the source container to the source host , Routing through data center , The process of arriving at the destination host and finally allocating to the destination container .

The whole process is always based on iptables Rules for routing and forwarding , There was no encapsulation , The process of unpacking , This sum flannel It will be much faster than that .

2.flannel principle

flannel adopt etcd The service maintains a routing table , According to the route UDP Encapsulation , We have to unpack when we reach the target , More wasteful CPU Resources for .

From the above principle, we can see ,flannel On the basis of routing and forwarding, the operation of packet unpacking is carried out , This is a waste CPU Computing resources for .