Research On Docker Containers Migration Technology

With the rapid development of virtualization technology,container technology has attracted more and more researchers' attention because of its advantages of quick start-up speed and occupiing less system resources.It is expected to become the mainstream virtualization application technology after virtual machine technology.Among many container technologies,Docker technology effectively solves the problem of overcomplicated operation of similar products,and it also has the advantage of facilitating large-scale deployment and migration.Therefore,it has received extensive attention from the academic community and the industry.However,with the continuous development of Docker technology applications,especially when it is deployed in a cluster or a cloud platform environment,the disadvantages of Docker containers are also revealed.The main manifestations are: system load imbalance and host hardware maintenance are difficult.In order to avoid the above problems and highlight the advantages of the Docker containers,the researchers proposed different Docker containers live migration solutions for different scenarios.Based on in-depth research on the current live migration of containers,the existing migration plan can achieve the goal of live migration of containers,but some solutions may generate more redundant intermediate images when the container data is migrated.The migration process of some solutions cannot be applied to between different storage drives.In order to solve the deficiencies of the current Docker live migration program,this paper uses container layer files and image layer files to be uniformly displayed by union mount in the union filesystem,and the characteristics of files that have been manipulated in the container exist in the container layer,and proposes a live migration solution for unterminated Docker containers.The program can realize the migration of the memory state information and container data of the Docker containers runtime.It not only ensures that no intermediate images will be generated during the migration of container data,but also that container data can be migrated between storage drivers of different union file backends.Based on the live migration of the above containers,this paper completed multiple sets of verification experiments on the two most common types of union filesystem storage drivers(aufs and overlay2).The experimental results show that the system does not generate redundantimages while successfully implementing the live migration of the Docker containers,and it effectively implements container data migration across the drives.Given cloud platforms also have virtualized application requirements,Docker technology has been integrated into the OpenStack cloud platform.This article is based on open source cloud platform OpenStack to achieve the application of the Docker container live migration program.Based on the container management module Zun in the new version of OpenStack released in August 2017(Pike version),this article designed and implemented a Docker container live migration function suitable for cloud platform application features.This function is similar to the migration of virtual machines in the cloud platform.Without stopping its internal service,the non-terminal Docker containers can be migrated between cloud hosts that have been deployed with union filesystem storage drives.Finally,the validity of the migration function is verified through the Zun command line.