Comparison of zero downtime based deployment techniques in public cloud infrastructure

The ever-metamorphosing nature of modern businesses demand changes to be rapidly deployed to the production environments without causing any major outages. Cloud computing in conjunction with containerization and orchestration technologies has undoubtedly contributed to the development and proliferation of quicker and light weight deployment strategies. Of late, Micro service architecture (MSA) has become the de-facto standard for building such lightweight containers, which made the deployments even quicker. Though public cloud technologies and MSA based containers helped in rapid deployments, continuous deployment with zero downtime is not something which comes out of the box. It needs the implementation of Blue Green (BG) deployment techniques to achieve the zero downtime with no disruption to end users while applying the patches. But there are multiple ways to implement the BG deployment pattern. This research paper aims to address three things - (i) Explore Blue Green, Canary and Rolling deployment techniques possible in the cloud platforms (ii) Perform a research project, to simulate the BG deployment strategies using DNS routing swap versus Load Balancer swap versus newer image switch techniques(iii) Draw the comparisons and elucidate which deployment strategy is suitable for which scenario.