Data streaming, workflow and firewall-friendly Grid Services with Styx

We present the Styx Grid Service (SGS), a remote service type that allows data to be streamed directly between service instances. The Styx Grid Service is built upon the Styx protocol, an established protocol for building distributed systems. Through the use of persistent connections, clients can monitor progress, status and other service data without requiring inbound ports to be open through the firewall. Security is assured through the use of SSL to authenticate and encrypt communications between systems. SGSs can interoperate with other service types such as Web Services in a workflow through the use of suitable wrappers. We present two case studies of the use of the SGS. In the first, Styx Grid Services are used in the streaming of large amounts of data between Web Services in a workflow. In the second case study we show how the Styx Grid Service architecture can be used in collaborative visualization and computational steering.