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Given by Tom Haupt at ACM Java Grande Meeting on June 12-13 99. Foils prepared July 6 99
Outside Index
Summary of Material
| This has overview of system/requirements, Middle Tier and PSE / Front End |
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The Gateway System
Goals
Design Issues
Towards a complete solution ...
Three-Tier Architecture
Target Architecture
Portal Page
User and Group Profile
Control Applet
Screen Dump of the Control Applet
Application Domain DataBases PSE Example: CCM
PPT Slide
Selecting a Predefined Task
Visual Authoring Tools
Example: Data Flow
Example: DARP
Example of a portal
Processing Task Specification
Other toolboxes
CORBA Based Middle-Tier
WebFlow Server
WebFlow Context Hierarchy
Module functionality
Middle-Tier modules serve as proxies of Back-End Services
Back End Services
WebFlow over Globus
Security Model (Keberos)
Outside Index
Summary of Material
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This project is a collaborative effort between
|
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| To provide a problem-oriented interface (a Web portal) to more effectively utilize HPC resources from the desktop via the Web browser. |
| This "point & click" view hides the underlying complexities and details of the HPC resources and creates a seamless interface between the user's problem description on his/her desktop system and the heterogeneous computing resources |
| These HPC resources include supercomputers, mass storage systems, databases, workstation clusters, collaborative tools, and visualization servers. |
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| Support for a seamless access (security) |
| Support for distributed, heterogeneous Back-End services (HPCC, DBMS, Internet, ...) managed independently from Gateway |
| Variable pool of resources: support for discovery and dynamical incorporation into the system |
| Scalable, extensible, low-maintenance Middle Tier |
| Web-based, extensible, customizable, self-adjusting to varying capacities and capabilities of clients (humans, software and hardware) front end |
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| Problem description:I need to model the surface damage due to the impact |
| of laser to harden the material bulk. I need access to models including |
| material bulk properties and interaction with intense electromagnetic fields. |
| Task description: I need 64 nodes of SP-2 at Argonne to run my |
| MPI-based executable "a.out" you can find in "/tmp/users/haupt" on marylin.npac.syr.edu. In addition, I need any idle workstation with jdk1.1 installed. Make sure that the output of my a.out is |
| transferred to that workstation |
| Middle-Tier: map the user's task description onto the resource specification; this may include resource discovery, and other services |
| Resource Specification |
| Resource Allocation: run, transfer data, run |
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| Back-End services |
| comprise Tier 3. |
| Distributed, object-based, |
| scalable, and reusable |
| Web server, Object broker |
| and Resource Manager |
| Middleware forms Tier 2 |
| Tier 1 is a high-level, browser-based Front End |
| for visual programming (including selection of applications, |
| generation of input data sets, specification of resources, |
| post-processing and visualizations) |
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| CTA specific knowledge databases |
| Visual |
| Authoring |
| Tools |
| User and |
| Group |
| Profiles |
| Resource Identification and Access |
| Visualizations |
| Collaboration |
| WebFlow |
| Back-End Resources |
| Problem Solving Environment |
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| Provides initial access to the Gateway. |
| After mutual authentication of the user and the Gateway server, creates a user context, and returns a (signed) control applet. |
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Controls the user/group environment
|
Allows for customization
|
| History of actions |
| Scientific notebook |
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| The control applet is responsible for maintaining the session, and direct communication with the middle-tier. |
| Direct communication is the most efficient, but since it is buried into an applet, this mechanism is not readily customizable. |
| The generic services, such as file service (upload, download, edit, copy, move, delete) and job services (show current jobs/show queues/kill jobs) will be supported this way. [combination of the user context and a query] |
| The Gateway will also support a non-direct communication with the middle-tier through servelts. |
HTML version of Basic Foils prepared July 6 99
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| Ken Flurchick, http://www.osc.edu/~kenf/theGateway |
| 1. Enter the Gateway system |
| 2. Define your problem |
| 3. Identify resources (software and hardware) |
| 4. Create input file |
| 5. Run your application |
| 6. Analyze results |
HTML version of Basic Foils prepared July 6 99
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| Allows for composition of the computational task from components (reusable modules) |
| Different tools to support various programming models such as data parallel, task parallel, data flow, object oriented |
| No assumption on granularity |
| Metadata about components and support for archiving and mining the components |
| Support for instrumentation and steering |
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HTML version of Basic Foils prepared July 6 99
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| Navigate and choose an existing application to solve the problem at hand. Import all necessary data. |
| Retrieve data |
| Pre/post-processing |
| Run simulations |
| Select host |
| Select model |
| Set parameters |
| Run |
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| XML |
| A visual representation is converted into a XML |
| document |
| XML |
| service |
| Web |
| Server |
| save |
| parse |
| ApplContext |
| Generates Java code to add modules to ApplContext |
| Publishes IOR |
| Front-End Applet |
| Middle-Tier |
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| Visualizations |
| Collaboration |
| Scientific notebook |
| ... |
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| Mesh of WebFlow Servers |
| implemented as CORBA objects |
| that manage and coordinate |
| distributed computation. |
| Gatekeeper |
| Authentication |
| Authorization |
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| User 1 |
| User 2 |
| Application 1 |
| Application 2 |
| App 2 |
| App 1 |
| WebFlow server is given |
| by a hierarchy of containers |
| and components |
| WebFlow server hosts users and services |
| Each user maintains a number of applications composed of custom modules and common services |
| WebFlow Services |
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| Master Server (Gatekeeper) |
| Slave Server |
| Slave Server |
| User Context |
| Application Context |
| Module |
| Slave Server Proxy |
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| May act as a client for a back-end service such as Globus GRAM or a database |
| May invoke other Gateway Middle Tier services such as File Services or Resource Discovery |
| May implement the desired functionality internally (say, in Java) [thus not a proxy] |
| May interact with other modules and the Front End through events |
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| Services |
| User Modules |
| Browser based Front-End |
| Browser |
| based |
| Front-End |
| User Space Definition and Task Specification |
| Metacomputing Services |
| Back-End Resources |
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| Access to HPCC (via Globus) |
| Access to distributed databases (via JDBC) |
| Access to mass storage |
| Access to the Internet resources |
| Access to desktop application and local data |
| Access to code repositories |
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| In order to run WebFlow over Globus there must be at least one WebFlow node capable of executing Globus commands, such as globusrun |
| Jobs that require computational power of massively parallel computers are directed to the Globus domain, while other jobs can be launched on much more modest platforms, such as the user's desktop or even a laptop running Windows NT. |
| Bridge between WebFlow and Globus |
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| SECIOP |
| Front End Applet |
| SECIOP |
| authentication |
| & authorization |
| Gatekeeper |
| delegation |
| HPCC resources |
| GSSAPI |
| GSSAPI |
| Layer 1: secure Web |
| Layer 2: secure CORBA |
| Layer 3: Secure access to resources |
| Policies defined by resource owners |