SODA: a service-on-demand architecture for application service hosting utility platforms

The grid is realizing the vision of providing computation as utility: computational jobs can be scheduled on-demand at grid hosts based on available computational capacity. In this project, we study another emerging usage of grid utility: the hosting of application services. Different from a computational job, an application service such as an e-Laboratory or an on-line business has longer lifetime, and performs multiple jobs requested by its clients. A service hosting utility platform (HUP) is formed by a set of hosts in the grid, and multiple application services will be hosted on the HUP. SODA is a service-on-demand architecture that enables on-demand creation of application services on a HUP. With SODA, an application service will be created in the form of a set of virtual service nodes; each node is a virtual machine which is physically a ´slice´ of a real host in the HUP. SODA involves both OS and middleware techniques, and has the following salient capabilities: (1) on-demand service priming: the image of an application service as well as the OS on which it runs will be created on-demand and bootstrapped automatically; (2) better service isolation: services sharing the same HUP host are isolated with respect to administration, faults, intrusion, and resources; (3) integrated service load management: for each service, a service switch will be created to direct client requests to appropriate virtual service nodes. Moreover, the application service provider can replace the default request switching policy with a service-specific policy.