You've seen some of the beauty of CIP at the architectural level. It's time to focus on one of its middleware services—the streamer service—as a case study, and examine some of the nails that allowed us to meet the mission's strict functional, reliability, and robustness requirements. You'll see that the nails were not particularly fancy; the beauty was in knowing just where to pound them in.
One of the MER mission's data management needs is to allow users to download data and image files from the mission file servers located at JPL to their personal workstations and laptops. As described earlier, CIP data-tier utilities generate metadata that allow users to find the files they want based on various search criteria. Users also need to upload files that contain their analysis reports to the servers.
CIP's streamer service performs file downloading and uploading. We gave the service that name because it streams the file data securely across the Internet between the mission file servers at JPL and users' local computers. It uses the web services protocol, so client applications can be written in any language that supports the protocol, and these applications are free to devise whatever GUI they deem suitable.
Like each of the other middleware services, the streamer service uses web services to receive client requests and to return responses. Each request is first fielded by the streamer service provider, which is implemented ...