mWarp: Accelerating Intra-Host Live Container Migration via Memory Warping
Piush K. Sinha, Spoorti Doddamani, Hui Lu, Kartik Gopalan · 2019
Live container migration allows containers to roam from one server to another to achieve agility goals like load balancing, tackling machine failures, scaling in/out and reallocating resources. However, migrating a container is also costly mainly due to memory state migration - a large number of memory pages need to be copied from the source server to the destination server. In this paper, we propose a fast and live container migration approach, mWarp, in an intra-host scenario, where both the source and destination virtual machine (VM) servers reside on the same physical host. Instead of copying a container's memory, mWarp relocates the ownership of the container's physical memory pages from the source VM to the destination VM with a highly-efficient memory remapping mechanism. As relocation of memory ownership is light-weight, mWarp leads to fast and live container migration with less service disruption to applications running in containers being migrated. We implement mWarp upon a well-known live container migration tool (CRIU) with key kernel/hypervisor-level support. The evaluation with both micro benchmarks and real-world applications shows that mWarp greatly reduces the total container migration time and downtime (e.g., by an order of magnitude) with significantly improved application-level performance (e.g., by 20%).