An immutable or disposable upgrade is an easier option if your application has unknown dependencies. An older application infrastructure that has been patched and re-patched over time becomes more and more difficult to upgrade. This type of upgrade technique is more common in an immutable infrastructure.
During the new release, a new set of server instances are rolled out by terminating older instances. For disposable upgrades, you can set up a cloned environment with deployment services such as Chef, Puppet, Ansible, and Terraform, or use them in combination with an auto scaling configuration to manage the updates.
In addition to downtime, you need to consider the cost while designing your deployment strategy. Consider the number of instances you need to replace and your deployment frequency to determine the cost. Use the approach that best fits, taking your budget and downtime into consideration.
In this section, you learned about various CD strategies that help...