Abstract: Container hot migration is the basis of cloud platform load balancing technology, and also an important guarantee for cluster fault management and underlying system maintenance. At present, the implementation of container hot migration is mainly based on checkpoint/restore mechanism， that is to do checkpoint operation on the running container, then stop the container, transfer the image file to the destination host, and then recover. The migration time includes checkpoint time, transmission time and recovery time. In order to reduce the downtime of container hot migration and reduce the transmission consumption, this paper designs and implements a container hot migration scheme based on pre-copy migration algorithm, and adopts the key technology of fast memory synchronization, which includes three methods: fine-grained dirty memory identification, dirty memory compression and transfer, and merging incremental memory in advance. Experiments show that the proposed scheme and optimization technology can significantly reduce the downtime and transmission overhead.

Key words: container, thermal migration, memory synchronization, virtualization