Efficient Live Migration Of Linux Containers

In recent years, operating system level virtualization has grown in popularity due to its capability to isolate multiple userspace environments and to allow for their co-existence within a single OS kernel instance. Checkpoint-restore in Userspace (CRIU) is a tool that allows to live migrate a hierarchy of processes - a container - between two physical computers. However, the live migration may cause significant delays when the applications running inside a container modify large amounts of memory faster than a container can be transferred over the network to a remote host. In this paper, we propose a novel approach for live migration of containers to address this issue by utilizing a recently published CRIU feature, the so-called "image cache/proxy". This feature allows for better total migration time and down time of the container applications that are migrated by avoiding the use of secondary storage.