Kate, at the moment I don’t think we have any documentation on deploying WSO2 Data Analytics Server or WSO2 API Manager Analytics on AWS ECS. Nevertheless, you can use the same concepts used for deploying WSO2 API Manager container in this blog post for deploying the analytics server container. The main difference between the two would be that analytics server would need a TCP endpoint for receiving API statistics and it would make a stateful TCP connection from the API manager container to the analytics container with client side failover. Either a domain name or a TCP load balancing endpoint can be used for this purpose. For enabling analytics you may need to configure the analytics endpoint URL and credentials in the repository/conf/api-manager.xml file in the API manager container. Please refer this documentation page for more details on the configurations needed.
On the other hand, you may also want to evaluate Amazon Elastic Container Service for Kubernetes (Amazon EKS) which was announced recently at the AWS re:Invent 2017 for allowing users run Kubernetes on AWS as a managed service. With this approach you will be able to deploy WSO2 API Manager and Analytics using WSO2 API Manager Kubernetes Resources with its standard deployment patterns.