Comparison between OpenStack virtual machines and Docker containers in regards to performance

Sammanfattning: Cloud computing is a fast growing technology which more and more companies are starting to use throughout the years. When deploying a cloud computing application it is important to know what kind of technology that you should use. Two popular technologies are containers and virtual machines. The objective with this study was to find out how the performance differs between Docker containers and OpenStack virtual machines in regards to memory usage, CPU utilization, time to boot up and throughput from a scalability perspective when scaling between two and four instances of containers and virtual machines. The comparison was done by having two different virtual machines running, one with Docker that ran the containers and another machine with OpenStack that was running a stack of my virtual machines. To gather the data from the virtual machines I used the command ”htop” and to get the data from the containers, I used the command ”Docker stats”. The results from the experiment showed a favor towards the Docker containers where the boot time on the virtual machines were between 280-320 seconds and the containers had between 5-8 seconds bootup time. The memory usage was more than doubled on the virtual machines than the containers. The CPU utilization and throughput favored the containers and the gap in performance increased when scaling the application outwards to four instances in all cases except for the throughput when adding information to a database. The conclusion that can be drawn from this is that Docker containers are favored over the OpenStack virtual machines from a performance perspective. There are still other aspects to think about regarding when choosing which technology to use when deploying a cloud application, such as security for example.