An interesting work that I was involved recently was around exploring the potential of Dynamic Clusters to provide differentiated Service Level Agreements (SLA) to tenants in a Software-as-a-Service delivery model.
What impressed me most was the fact that we can cluster web application servers like Tomcat or WebSphere Application Server - Community Edition (WAS-CE) in a cluster with dynamic behavioral attributes. These clusters, when configured can intelligently behave depending on the incoming traffic to satisfy the response time SLAs for a particular tenant. For example, if there is an increased load and the response time policies are breached for a high paying tenant, servers (in the dynamic cluster) can automatically be started from the server pool to cater to the increased computational demand.
It is indeed relevant for Software-as-a-Service platform providers where in, each tenant can be provided with differentiated response time targets (service levels) and the underlying infrastructure can be setup to meet such a differentiated requirement. Sharing of server pools across multiple tenants can potentially increase hardware utilization.
This also can be used to explore new charge back models based on the service levels offered to tenants. Applications that can be deployed on free application servers like WAS-CE have a great potential to explore such topologies in my opinion. Well, not to mention that this molecular virtualization using WebSphere Virtual Enterprise is a very interesting and emerging topic when we speak about "The CLOUD"!..