Final answer:
Elastic Beanstalk deployment policies determine how updates are applied across instances in the AWS cloud, with specific options for load-balanced, single-instance, and Windows Server environments.
Step-by-step explanation:
Supported Deployment Policies in Elastic Beanstalk
Amazon's Elastic Beanstalk allows developers to deploy and manage applications in the AWS cloud without having to understand the underlying infrastructure. Within Elastic Beanstalk, deployment policies dictate how the application is updated across the environment's instances. For load-balanced environments, several deployment policies are available, including All at once, Rolling, Rolling with additional batch, Immutable, and Blue/Green deployments. Each policy handles the rollout of new application versions differently, balancing speed, downtime, and risk. In single-instance environments, the typical deployment occurs all at once since there's only one instance.
Windows Server environments in Elastic Beanstalk, on the other hand, offer similar deployment policy options to load-balanced environments, but there are certain considerations to take into account specific to Windows, such as the need to handle .NET applications and IIS settings.
The choice of deployment policy in any of these environments should reflect the criticality of the application, the acceptable level of downtime, and the risk appetite for any disruption or errors during deployment.