Using the Visualization Server
The Visualization Server Software Architecture
In order to use the visualization server as a grid resource, WestGrid has deployed SGI's VizServer software on the WestGrid visualization machine hydra.westgrid.ca. This machine is a large SGI visualization machine. The VizServer software allows remote users to run complex visualizations using hydra's advanced computational and graphics resources. Pixel data from the visualizations are sent over the network to a lightweight client that runs on commodity desktop machines. This implies that the performance requirements are independent of the size of the data set being visualized and depends only on the size of the image that the user wants to display. As long as the network is architected to provide sufficient bandwidth to the end user, very large and complex visualization tasks can be undertaken with no more client side costs than that required for a simple visualization. This architecture therefore treats the visualization server as a true grid resource that can be used by any user in the WestGrid community.
Installing the VizServer Client Software
Installing the VizServer client software is straightforward for both Windows (Win2K, XP) and Linux (RH 6.2 or later). The Windows install is provided as a typical Windows installer, while the Linux install is provided as a tarball.
Using the VizServer Software
To use the VizServer software on hydra you will need a valid user id on the machine. Although you do not need to log in to hydra directly you will need to authenticate to the machine to gain access using the VizServer software. All WestGrid users have accounts on hydra, so the machine should be accesible using your normal WestGrid user and passwords.
In order to maintain security while using the VizServer software, it is necessary to use a secure shell tunnel. Unfortunately the VizServer software control protocol is sent over the network in clear text, including the authentication information. In order to maintain adequate security we enforce the use of ssh tunnels to gain access to the VizServer service. Note that only the VizServer control protocol is encoded using the ssh tunnel. The visualization data stream is sent over the network unencrypted. For information on how to use VizServer over an ssh tunnel on Windows and Linux, please refer to the VizServer SSH Tunnel documentation.
SGI provides user guide documentation on how to use VizServer. Users are referred to this document for detailed information on how to use the VizServer software.
