With more than 140 million users, KakaoTalk is the most popular mobile messaging platform in South Korea. The team at daumkakao has been using OpenStack with the intention for tranforming the current legacy infrastructure into scale out based cloud to build and offer new services for its users. In this session, we'd like to share our experiences with the OpenStack community, specifically in regards to meeting our needs for networking with Neutron.
OpenStack Neutron offers a lot of methods to implement networking for VMs and containers. For production operations, VM migration can be a common activity to manage resources and improve uptime. It's not hard using shared storage like Ceph, but network settings, such as IP addresses need to be preserved. With a shared storage environment, an image can be attached anywhere inside of a data center, but a service IP for a virtual machine is different story. And when you don't use the floating IPs, keeping the same IP across a data center-wide set of VLANs is hard job.
To maintain a virtual machine's IP settings and balance IPs between VLANS, we tried several options including overlay, SDN, and NFV technologies. In the end we came to use a route-only network for our virtual machine networks, leveraging technology like Quagga for RIP, OSPF BGP integrated with Neutron.