simulation

 

Real-Time Simulation Monitoring

The natural evolution of ViSUS

Ideally, a user-scientist would like to view a simulation as it is computed, in order to steer or correct the simulation as unforeseen events arise. Simulation data is often very large. For instance, a single field of a time-step from the S3D combustion simulation (shown above) is approximately 128 GB in size. In the time needed to transfer this single time-step, the user-scientist would have lost any chance for significant steering/correction of an ongoing simulation or at least take the opportunity to save computing resources by early termination of a job that is not useful anymore. By using the parallel ViSUS data format in simulation checkpointing, we can link this data directly with an Apache server using a ViSUS plug-in running on a node of the cluster system. By doing this, user-scientists can visualize simulation data as checkpoints are reached. ViSUS can handle missing or partial data, therefore the data can be visualized even as it is being written to disk by the system.

ViSUS's support for a wide-variety of clients (a stand-alone application, a web-browser plug-in, or an iOS application for the iPad or iPhone) allows the application scientist to monitor a simulation as it is produced, on practically any system that is available without any need to transfer the data off the computing cluster.

This work is the natural evolution of the ViSUS approach of targeting practical applications for out-of-core data analysis and visualization. This approach has been used for direct streaming and real-time remote monitoring of the early large scale simulations such as those executed on the IBM BG/L supercomputers at LLNL. This work continues its evolution towards the deployment of high performance tools for in-situ and post-processing data management and analysis for the software and hardware resources of the future including exascale DOE platforms of the next decade.