HP Scalable Visualization Array Software - Manual (Page 12)

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 1-2 illustrates the makeup
of a standalone SVA.
Figure 1-2 Standalone SVA Data Flow
OpenGL Graphics
User Application
Master Node
user interface
transfer simulation data
and drawing commands
display nodes
System Interconnect
Card
OpenGL Graphics
Card
OpenGL Graphics
Card
OpenGL Graphics
Card
multi-tile display
render nodes
OpenGL Graphics
Card
OpenGL Graphics
Card
OpenGL Graphics
Card
Key points of Figure 1-2 are 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 1-2 also 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