Center for Simulation of Advanced Rockets

Voyager

Voyager is a batch mode version of Rocketeer that processes in parallel a series of snapshots from a simulation. It shares its code base with Rocketeer and has nearly all of the capabilities of the interactive version. Voyager is a command line tool that takes as arguments a camera position file, a graphics operations file, and a list of HDF files to process. The camera postion and graphics operations files are generated during an interactive session of Rocketeer using a representative snapshot.

Voyager uses MPI to pass messages. Once each processor knows which files to process, the camera position, what graphics operations to perform, and the ranges of the data for the color scales, it can generate each individual image and save it to disk without additional communication. If the files reside on local disk, Voyager is scalable to large numbers of processors. Even if the files reside on a shared file system, Voyager scales well until contention for I/O bandwidth becomes significant. On subsequent runs with the same data (but possibly different camera positions, isosurface values, etc.) Voyager scales well if much of the data have been saved by the system in local disk caches.

Like Rocketeer, Voyager works with Mesa / XFree86. However, for use on a large cluster, CSAR contracted with Xi Graphics to develop a commercial quality X server with a virtual frame buffer that installs automatically on all nodes without regard to the graphics hardware or requiring administrator intervention.

Voyager is available on the Turing cluster at
/turing/projects/csar/CSAR_Vis/v1.3.6/bin .

Documentation

Man page on how to use Voyager.

Conference Paper

Massively Parallel Visualization on Linux Clusters with Rocketeer Voyager, presented at Linux Clusters: the HPC Revolution on June 26, 2001 at NCSA.