To emulate this behavior the Linux bridge must deliver broadcast packets to every port of the bridge. In a physical network such as Ethernet a broadcast packet is placed on the wire once and is available to each node to receive or discard. I found the major obstacle in scaling a bridge is the handling of broadcast packets. The Linux bridge emulates a layer 2 network supporting the sending of unicast, multicast and broadcast messages between its nodes. In this post I will discuss the issues I encountered when scaling the Bridge network and the solutions I implemented.ĭocker's bridge network is built using the Linux bridge. I found that when network activity is pushed to multiple thousands of containers I started seeing bottlenecks in the Linux kernel resulting in dropped packets and unreliable throughput. Can Docker's virtual network scale to 10,000 endpoints? I conducted experiments to explore this question. Spinning up 10,000 containers is indeed a big accomplishment however, to be useful containers need network connectivity. You can read more about this accomplishment here: IBM has boasted that 10,000 docker containers can simultaneously be spun-up on a single IBM Power8 host. Scaling the Docker Bridge Network – By David J.
