HP Scalable Visualization Array (SVA) Software manual SVA Clusters, Standalone SVA Data Flow

The SVA serves as a key unit in an integrated computing environment that displays the results of generated data in locations where scientists and engineers can most effectively carry out analyses individually or collaboratively.

SVA Clusters

This section gives a high-level description of a standalone SVA, that is, an HP Cluster Platform system built using visualization nodes. The SVA can also provide a visualization solution that is fully integrated into an existing HP Cluster Platform system with compute and storage components, as shown in Figure 1-1.

The SVA image-based approach works with a variety of visualization techniques, including isosurface extraction and volume visualization. Such a graphics architecture combines the high performance of clusters of rendering machines with the interactivity made possible by the speed, scalability, and low latency of the cluster network.

HP SVA offers a graphics visualization solution that can be used by a variety of applications that run on distributed computing systems; in this case, a cluster of Linux workstations. Figure 1-2illustrates the makeup of a standalone SVA.

Figure 1-2 Standalone SVA Data Flow

multi-tile display

			Master Node		user interface
	System Interconnect		User Application		transfer simulation data
					and drawing commands
OpenGL Graphics	OpenGL Graphics	OpenGL Graphics		OpenGL Graphics		OpenGL Graphics
Card	Card		Card		Card	Card
OpenGL Graphics
Card			display nodes
OpenGL Graphics
Card
render nodes

Key points of Figure 1-2are the following:

•Industry standard workstations with standard OpenGL 3D graphics cards serve as visualization nodes (render and display), and run clustering software and Linux. Use of industry standard graphics cards lets the system take advantage of new generations of cards as they become available.

•Depending on the design of the application, an application “master” can run the application and the user interface for the application on a specified node.

•Display nodes transfer their rendered output to the display devices and can synchronize multi-tile displays. A range of displays are supported at locations local and remote to the SVA. A series of render nodes can also contribute composited images to the display nodes, depending on the visualization application.

•The System Interconnect (SI) supports data transfer among visualization nodes. High-speed, low-latency networks such as InfiniBand and Myrinet can be used for the SI to speed the transfer of image data and drawing commands to the visualization nodes.

Each portion of an image is rendered on its visualization node as determined by the application and the visualization middleware being used. For example, you can use Chromium or a scenegraph application in conjunction with Distributed MultiHead X (DMX). The final images are transmitted by the graphics cards in the display nodes to the display devices.

Final images can also be transmitted to a remote workstation display over a network external to the cluster. This lets users interact with applications running on the cluster from their offices. Optionally, you can use HP Remote Graphics Software (RGS) to accomplish this more easily.

Figure 1-2also shows a master application node communicating with the other visualization nodes over the SI. The SI carries file I/O and application communications; for example, MPI traffic. The user interface for a visualization application can run on a master application node and communicate with the visualization nodes over the SI, sending control information such as changes in point of view, data, or OpenGL commands.

12 Introduction