HP Scalable Visualization Array Version 2.
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Table of Contents About This Document.........................................................................................................9 1 Intended Audience..................................................................................................................................9 2 Document Organization..........................................................................................................................9 3 Typographic Conventions.............................................
.3.4 Run an Application Using HP RGS...............................................................................................34 5 Setting Up and Running a Visualization Session......................................................37 5.1 Configuration Data Files......................................................................................................................37 5.2 Running an Application Using Scripts..................................................................................
List of Figures 1-1 1-2 1-3 2-1 3-1 3-2 6-1 6-2 6-3 System View of a Computing Environment with Integrated SVA...............................................11 Standalone SVA Data Flow............................................................................................................12 Software Support for Application Development and Use............................................................14 SVA Data Flow Overview...............................................................................
List of Tables 3-1 3-2 3-3 3-4 3-5 6-1 Operating System and Driver Components..................................................................................27 HP XC System Components Relevant to SVA Operation.............................................................28 HP SVA System Software..............................................................................................................28 Third Party System Software..........................................................................
About This Document The SVA User's Guide introduces the components of the HP Scalable Visualization Array (SVA). The SVA product has hardware and software components that together make up the HP high performance visualization cluster. This document provides a high level understanding of SVA components.
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1 Introduction This chapter gives an overview of the HP Scalable Visualization Array (SVA). It describes how the SVA works within the context of overall HP cluster solutions. It also discusses attributes of the SVA that make it a powerful tool for running data intensive graphics applications. The SVA is a scalable visualization solution that brings the power of parallel computing to bear on many demanding visualization challenges.
is also available for display remotely, but limited to single or two-tile output from a single graphics card. 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. 1.2 SVA Clusters This section gives a high-level description of a standalone SVA, that is, an HP Cluster Platform system built to include visualization nodes.
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.
1.4.2 Flexibility One of the most powerful attributes of the SVA is its flexibility, which makes it possible to apply the SVA effectively to a wide range of technical problems. This flexibility derives from the architectural characteristics of the SVA.
full advantage of the various toolkits and libraries. The SVA uses standards such as OpenGL, Linux, InfiniBand, and Gigabit Ethernet for portability and interoperability. The HP Parallel Compositing Library that ships with SVA can help application developers accomplish parallel rendering. See the SVA Parallel Compositing Reference Guide. To achieve maximum performance scaling when running on the SVA, an application must be parallel and distributed.
2 SVA Architecture This chapter gives a detailed look at the architecture of the HP Scalable Visualization Array (SVA). It compares the SVA to other clusters and describes the flow of data within the cluster. 2.1 SVA as a Cluster It is important to understand the cluster characteristics of the SVA. These characteristics have implications for how SVA functions. They also affect how applications take advantage of cluster features to achieve graphical performance and display goals. 2.1.
Thus, the SVA provides the HP Cluster Platform with a visualization component for those applications that require visualization in addition to computation. The following sections describe the components that make up an HP Cluster Platform, followed by those tasks and components that are unique to an SVA. 2.2.1 Components of the HP Cluster Platform Because the SVA is an extension of the HP Cluster Platform, you can begin by understanding its base components without any visualization nodes.
Remote images. Integrate an application user interface. images. The output can be a complete display or one tile of an aggregate display. The SVA also supports the transmission of a complete image to a system external to the cluster over an external network for remote viewing; for example, to an office workstation outside the lab. A node with a port connected to the external network is recommended.
• • • • Multiple displays with different resolutions. Use of a variable number of display and render nodes to solve the computational and rendering requirements of an application. Bounded configuration designed for a single user. Larger, modular, expandable systems designed for one or more concurrent users. See Chapter 3 for more information on the physical configurations of the SVA. 2.3 SVA Operation This section describes a common way data flows through an SVA. 2.3.
features extracted based on application settings. The application then caches the results of the analysis or rendering to display an animation of the time steps. Although parallel visualization is a relatively new approach, some file access patterns that applications use include the following: • Master portion of the application reads data from files and distributes data to visualization nodes using the SI. • Visualization nodes all read data from the same files.
3 SVA Hardware and Software This chapter provides information on the hardware and software that make up the SVA. It is a useful reference for anyone involved in managing the SVA. It is also useful for anyone who wants to understand the hardware that makes up the SVA and the software that is installed on it. The SVA combines commodity hardware components with software that include the following: • A cluster of Intel EM64T or AMD-64 Opteron HP workstations and servers as visualization nodes.
Platform system, the visualization nodes can use a high speed system interconnect to load data from an HP SFS. The two SVA physical configurations are built using one or more of three types of cluster building blocks. Each building block uses a single rack. Utility Visualization Block (UVB) Utility Building Block (UBB) Visualization Building Block (VBB) Base utility unit of a Bounded Configuration.
Figure 3-1 Sample SVA Bounded Configuration Base Rack (UVB) GigE Display Devices External Node 3.3 Modular Packaging Configuration A Modular Packaging Configuration is built from the UBB and VBB rack systems. It has the following components as summarized in Chapter 2: • Render and Display nodes. Workstations: xw8200, xw8400, or xw9300 or servers: DL140 G3. • Head node. DL380 G4 or a DL385 G4 server. • • Optional KVM.
The management switches are collected together in one rack. SVA nodes connect to branch switches in the Administrative Network. SVA nodes do not connect to the console branch. Nodes connect to the switches according to the Cluster Platform Administrative Network connections for HP XC. Display and render node types are typically grouped together. 3.
Figure 3-2 Software Hierarchy in the SVA Applications Launch Visualization Libraries (optional) OpenGL Initialize Cleanup X Servers HP XC Linux SVA Software Utilities Allocate Cluster Nodes and Displays 3.6.1 Linux Operating System The SVA software is layered on top of HP XC System Software Version 3.1, a clustering Linux distribution compatible with Red Hat Enterprise Linux Advanced Server V4.0 Update 3. The kernel version is V2.6.9–x. See Section 3.6.2.
• • Naming each of the nodes in the cluster and determining which nodes are up and running. Serializing application use of the cluster. For more information on HP XC, consult the HP XC documentation set at the following Web site: http://docs.hp.com/en/highperfcomp.html Table 3-2 summarizes the software components that are provided by the HP XC operating system that relate to the SVA.
Table 3-4 Third Party System Software Software Description OpenGL Primary interface programmers use to create images. http://www.opengl.org/ OpenGL Utility library (GLU) Contains routines that build on the lower level OpenGL library to perform such tasks as setting up matrices for specific viewing orientations and projections, performing polygon tessellation, and rendering surfaces.
4 Quick Start This chapter lets you quickly try some of the sample applications on the SVA Kit. Details on using scripts are provided in other chapters of this HP SVA User's Guide and other documents in the online HP SVA Documentation Library. 4.1 Typical Uses of SVA SVA has three primary usage scenarios as described in detail in Chapter 6. • • • A workstation application that is launched remotely to use only a single node in the SVA.
TIP: See the HP SVA System Administration Guide for detailed information on how to define Display Surfaces, including a recommended incremental series of steps for configuring SVA for your displays. • Verify and possibly modify supported resolutions, display modelines, and refresh rates. This step is likely to be required for stereo displays and more exotic mono displays. Typical desktop display devices (monitors and flat panels) are supported by default by SVA.
• • In the case of third-party applications, for example, ParaView and EnSight, there is a separate user interface whose location is determined by setting the DISPLAY environment variable before you run the application. In the specific case of the SVA sva_chromium_dmx.sh script only: Use the -i option or set the DISPLAY environment variable to specify the node from which you want to provide input.
• • • You need to substitute the name of the site-specific input node for YOUR_INPUT_NODE. The city application is shipped with the SVA kit and is already on your PATH. It is a good application for seeing that the image is properly aligned among the individual tiles of a multi-tile display. It is possible that you do not see any images on the input node's monitor; it could appear blank. This is because the graphics card only supports one resolution at a time.
% sva_remote.sh -I (Note that problems sometimes occur running the script or logging into the Linux GUI. Check your login file for incompatible settings.) 3. HP RGS displays the name of the node it is connecting to on the cluster. Make a note of the name. 4. Immediately start the RGS Receiver application on your desktop. It's helpful to have an icon available for this. 5. Enter the name of the connected sender node into the Receiver window. Click on the Go button in the Receiver window. 6.
5 Setting Up and Running a Visualization Session This chapter explains how to run visualization applications on the SVA. A visualization session relies primarily on HP XC utilities to do the underlying work; however, you can avoid manually using the underlying utilities by means of job launch scripts and associated templates provided by the SVA kit. For details on HP XC utilities, see the HP XC system documentation (link available from the SVA Documentation Library). 5.
5.2 Running an Application Using Scripts Typically, you encapsulate the various commands needed to run applications using a script file. This speeds the process of running the application, given the likelihood that this is a task you repeat. The installation of the SVA Software Kit provides several general purpose script templates. These templates are the starting points for creating scripts to launch your own application.
Tip: A useful feature of the sva_chromium_dmx.sh script is its interactive mode for running all sorts of applications, including regular X Server applications. For example, you can display high resolution images with a variety of applications, or you can run standard OpenGL applications with Chromium. The script provides an easy way to take advantage of a multi-tile display. See Section 5.3 for more information on running an interactive session. • sva_remote.
Each template has default options that you can respecify. These options are documented in the SVA Visualization System Software Reference Guide, and in manpages for each template or fully functional script. The following command runs the atlantis application on the FULL_DISPLAY Display Surface using the Chromium/DMX launch script. The application-specific command-line parameter -count 20 is used. % sva_chromium_dmx.
it on the multi-tile display; for example, to display high-resolution images or to launch an application like ParaView. Tip: For convenience, you can create desktop icons as shortcuts to application launch commands. 5.4 Use Head or RGS Nodes in a Job There are situations when you want to use the head node or an RGS node as part of a job. In this case, the RGS node is one that you've connected to from your local desktop. Both of these are possible using the --local option on an SVA job launch script.
Depending on the number of nodes in a cluster, any user can rely on the job launch scripts to dynamically allocate nodes in efficient ways. For example, assume a cluster has six display nodes, two render nodes, and two site-specific Display Surfaces: • • BigDisplay: This is for a 3x2 array. SmallDisplay: This is for a 2x2 array. By using a job launch script based on sva_job_template.sh, you can specify the SmallDisplay Display Surface and four render nodes via the -r command option.
The following SVA launch scripts support the --stereo option. • • • sva_chromium_dmx.sh sva_paraview.sh sva_job_template.sh CAUTION: The stereo capabilities in SVA best support a single class of mono display devices and a single class of stereo display devices. A class of display devices is defined by the properties of the display, such as refresh rate and resolution. A system administrator can configure the SVA to support a range of display properties.
See the SVA Visualization System Software Reference Guide for more information on all the scripting functions, including svaEnableFrameLock. 5.7.3 Use the Framelock Utility SVA also has a utility called svacontrolframelock to turn hardware framelock on and off at any time. It is particularly helpful when used in the context of an SVA job.
6 Application Examples This chapter describes the steps to start several representative applications that vary in their structure and requirements: • • • A workstation application that is launched remotely to use only a single node in the SVA. See Section 6.1. An application that uses render and display capabilities of the SVA (for example, ParaView). See Section 6.2. A workstation application that uses Chromium software and DMX to display on multiple tiles using the SVA. See Section 6.3.
although you may consider it your local workstation. In this chapter, your local workstation is meant to designate a machine that is remote to the SVA. Working in this way lets you take advantage of the more powerful features of the cluster. These include more powerful graphics cards, or specific software libraries such as OpenGL extensions. It is also helpful and convenient for testing and debugging your application. It also facilitates collaborative work.
There are four processes that must run when a remote visualization session begins. • • • • The X Server. RGS Sender on the SVA RGS-capable node. RGS Receiver on your local desktop. Your visualization application. Figure 6-1 Using a Single SVA Node from Local Desktop Display Node User Application X Server RGS Sender G igE SI G igE GFX Display Device (attached to SVA) RGS Receiver Local Desktop 6.1.
SVA if you specify a Display Surface when you start the launch script. Alternatively, if you choose not to specify a Display Surface and accept a default node that is RGS-enabled, your display output may only appear remotely. This takes place when the assigned node is a render node rather than a display node. Refer to the SVA Visualization System Software Reference Guide for detailed syntax of script options.
The window immediately displays the external name of the display node running the atlantis application. You need this name for the next step. 3. Start the RGS Receiver on your local desktop. In the RGS window that appears, enter the external name of the display node in the Connect to Sender field. Click Go. The RGS login window appears. 4. Enter in the RGS login window your Linux user name and password assigned for the SVA cluster.
The atlantis application display begins. 7. Exit the application to stop the application only. You can then restart the application using the same application command or another command, including a command with a different application. Cluster resources remain allocated. To deallocate the cluster resources and stop the RGS process on the cluster, exit the desktop environment completely. Provide input to the application while it is running using the local desktop keyboard and mouse.
• • • • • • • level-of-detail models can be rendered locally whereas the full model is rendered in a distributed manner). This provides scalable rendering for large datasets without sacrificing performance when working with smaller datasets. ParaView supports tiled displays through a built-in display manager. Handles structured (uniform rectilinear, non-uniform rectilinear, and curvilinear grids), unstructured, polygonal, and image data. All processing operations (filters) produce datasets.
Figure 6-2 ParaView Flow of Control on the SVA Paraview Server Paraview Server Render Nodes Paraview Server Local Desktop Display Node 1 (Execution Host) Paraview Server X Server X Server File Paraview Client G igE To External Network Paraview Client Window SI G igE GFX Keyboard To Display Device Display Node 2 Display Device (2 tiles) Paraview Server X Server G igE SI G igE GFX To Display Device Follow these steps to run ParaView on the SVA.
5. (The ic-name is the HP XC convention used to denote that the SI communication mode is to be used.) To terminate ParaView, select the File: Exit menu item from the ParaView Console window on your desktop. Kill the various X Servers on the allocated cluster nodes. You can use the SLURM scancel command. Once you complete these steps, ParaView runs on the cluster while you maintain control of the application from your local desktop.
Reference Guide describe how to use launch templates to run applications, including the underlying functions and commands contained in the script. 6.3 Running a Workstation Application Using a Multi-Tile Display This section describes how to run a serial workstation application on the SVA using Chromium and DMX. 6.3.1 Assumptions and Goal This example assumes you have a visualization application that currently runs on a single workstation.
6.3.4 Location for Application Execution and Control Although an application can run on any node in the SVA, HP recommends that you run it on one of the display nodes. The SVA is configured to use the default Execution Host for the Display Surface you choose when launching the visualization job. The Execution Host for a Display Surface is the default location for running an application.
Figure 6-3 Processes Running with Chromium-DMX Script External Node Display Node 1 X Server Xdmx Chromium Application X Server G igE DMX cursor Console Window To External Network SI G igE GFX Keyboard To Display Device Display Node 2 Display Device (2 tiles) Chromium X X Server G igE SI G igE GFX To Display Device 6.3.5 Data Access For a serial application that uses Chromium, place the data files in a convenient location for your site configuration.
The primary mechanism that you use to set up displays is the Display Surface. A Display Surface is composed of one or more display nodes and their associated display devices; for example, a simple Display Surface is a specific display node and an attached flat panel display device. Initial configuration of the SVA sets up a series of default named Display Surfaces, one for each display node and its directly cabled display device.
Glossary Administrative Network Connects all nodes in the cluster. In an HP XC compute cluster, this consists of two branches: the Administrative Network and the Console Network. This private local Ethernet network runs TCP/IP. The Administrative Network is Gigabit Ethernet (GigE); the Console Network is 10/100 BaseT. Because the visualization nodes do not support console functions, visualization nodes are not connected to a console branch.
modular packing configuration This SVA configuration has two or more racks as needed to contain from four to ninety-five workstations or servers, along with a server head node. This configuration is based on HP Cluster Platform building blocks, namely the Visualization Building Block (VBB) and the Utility Building Block (UBB). It can be exclusively visualization nodes or be combined with compute nodes as part of an integrated HP Cluster Platform system.
Index A H Admin/service node, 18 Administrative network, 18, 24, 25 Architecture of SVA, 17 Head node, 18 use in visualization job, 41 HP Mlib, 29 B I Beowulf cluster, 17 Bounded configuration, 23 Interactive session how to run, 40 provide input to, 55 C Chromium, 28 Compilers on kit, 29 Compute cluster components of, 18 Compute node, 18 Configuration data files hierarchy of, 37 job settings, 37 overview, 37 site, 37 user, 37 D Data flow within SVA, 20 Debugger on kit, 29 Development tools, 29 Diag
Render node, 19 in SVA, 19 RGS example use, 46 launched via script, 48 launching of process, 47 RGS Display flow of control for, 46 RGS node route display to local desktop from, 41 Run application, 38 S Sample program types of, 45 Scripts used for launching applications, 39 used for stereo applications, 42 Serial application example use, 54 Site Configuration file, 37 SLURM use in job launch, 39 Stereo display use by job script, 42 SVA architecture for, 17 cluster components, 19 data flow in, 20 file acces
