Deploying a Spring Boot application as a Docker image in AWS Cloud can be done using several services: Amazon ECS (Elastic Container Service), Amazon EKS (Elastic Kubernetes Service), or self-managed Kubernetes on AWS. Here's an overview of the steps for each option, along with their advantages, disadvantages, and cost-effectiveness.

1. Amazon ECS (Elastic Container Service)

Steps to Deploy in ECS:

1. Create a Docker Image of your Spring Boot application and push it to Amazon ECR (Elastic Container Registry).
2. Create an ECS Cluster using either Fargate (serverless) or EC2 as the underlying infrastructure.
3. Define a Task Definition that specifies the Docker image, container ports, and memory/CPU requirements.
4. Configure a Service in ECS that links the task definition to the desired number of replicas (auto-scaling) and load balancer (if required).
5. Deploy your service and monitor via CloudWatch and ECS dashboard.

Advantages of ECS:

• Managed service: ECS handles the orchestration, scaling, and health monitoring of containers.
• Integration with Fargate: You can deploy without managing EC2 instances, reducing operational overhead.
• Tight AWS integration: Easy integration with AWS services like IAM, CloudWatch, ALB, and VPCs.

Disadvantages of ECS:

• Less flexibility compared to Kubernetes for complex workloads.
• Vendor lock-in with AWS.
• ECS has limited ecosystem support compared to Kubernetes for third-party tooling.

Cost-effectiveness:

• ECS with Fargate is cost-effective for smaller workloads or when you don’t want to manage EC2 instances.
• You pay for the vCPU and memory resources your containers use. No cost for managing underlying infrastructure.
• ECS on EC2 can become more expensive if not properly optimized, as you're paying for full EC2 instances.

2. Amazon EKS (Elastic Kubernetes Service)

Steps to Deploy in EKS:

1. Push your Docker image to ECR.
2. Create an EKS Cluster with worker nodes on EC2 or EKS Fargate for serverless deployments.
3. Configure kubectl or AWS CLI to connect to the EKS cluster.
4. Define your Kubernetes Deployment (including replicas, resource requests) and service (LoadBalancer or Ingress).
5. Apply the Kubernetes manifest files to deploy your application via kubectl.
6. Monitor with CloudWatch or use Kubernetes-native tools like Prometheus and Grafana.

Advantages of EKS:

• Kubernetes-native: You can run your Spring Boot application on Kubernetes, which offers the most flexibility and customizability.
• Huge ecosystem: Kubernetes has a large community and ecosystem for monitoring, logging, CI/CD, and autoscaling.
• Multi-cloud: Kubernetes allows easier migration between clouds or even hybrid cloud setups.

Disadvantages of EKS:

• Complexity: Kubernetes is harder to manage and configure compared to ECS. Even with EKS, you need to manage various Kubernetes components.
• Higher operational overhead: More expertise is needed to handle Kubernetes, even though AWS manages the control plane.

Cost-effectiveness:

• EKS with Fargate can be cost-effective for smaller workloads as there is no need to manage EC2 instances.
• However, EKS with EC2 instances can lead to higher costs due to the need to manage and optimize the nodes.
• You are charged for the EKS control plane (~$74/month per cluster) in addition to EC2 or Fargate resource costs.

3. Self-managed Kubernetes on AWS (kops or kubeadm)

Steps to Deploy on Kubernetes (Self-managed):

1. Set up an EC2 instance or multiple EC2 instances for your Kubernetes cluster.
2. Use kops (Kubernetes Operations) or kubeadm to create the Kubernetes cluster.
3. Push the Docker image to ECR or any other Docker registry.
4. Configure kubectl to manage the cluster.
5. Define your Kubernetes deployment and service.
6. Deploy your application with kubectl and monitor.

Advantages of Self-managed Kubernetes:

• Full control: You have complete control over the cluster, configuration, and operations.
• No AWS service cost: You are not paying for EKS control plane management.

Disadvantages of Self-managed Kubernetes:

• High operational complexity: You are responsible for cluster management, security updates, scaling, and monitoring.
• Limited AWS integration: While possible, manual integration is required for AWS services.
• Scaling difficulty: Self-managed clusters need more effort for scaling and disaster recovery.

Cost-effectiveness:

• This option can be cost-efficient for large-scale, long-running applications if you have expertise in managing Kubernetes.
• However, it's less cost-effective due to the operational complexity and time required to manage infrastructure compared to using EKS or ECS.

Cost-effective Recommendations:

1. For smaller workloads or if you want to avoid managing infrastructure, ECS with Fargate is the most cost-effective and easiest option. It provides a serverless experience and scales based on demand without EC2 management.
2. For medium to large-scale applications that need Kubernetes capabilities, EKS with Fargate could be a good balance between cost and flexibility. You avoid the overhead of managing EC2 nodes but still get the power of Kubernetes.
3. If you're experienced in Kubernetes and want full control over your infrastructure for a complex or large-scale system, self-managed Kubernetes could be considered, but it will likely require more operational effort.

Each option has trade-offs in terms of flexibility, management, and cost, but for most cases, ECS or EKS with Fargate should be the most cost-effective unless your application has specific Kubernetes needs.