jGMA: A WideArea Messaging and Resource Discovery System

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jGMA A Wide-Area Messaging and Resource
Discovery System
Matthew Grove ICG Student PresentationsJune
2005
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Outline

• Introduction and motivation,
• The architecture of jGMA,
• Message passing,
• Resource discovery,
• Current status,
• Demo,
• Future work.

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Introduction

• jGMA was initially designed to be a
  standards-based messaging layer to bind
  together the global layer of a project called
  GridRM,
• jGMA requirements
• Provide message passing and resource discovery,
• Work locally over a LAN or a wide-area, such as
  the Internet,
• Fast, and have a minimal impact on its hosts,
• Scalable,
• Able to work through firewalls,
• Compliant to the GMA specification.

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Design Philosophy

• Reuse existing software components, if possible,
  rather than reinvent functionality,
• Simple to install, configure and use,
• Provide a basic release with a choice to extend
  functionality with a further more sophisticated
  component.

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Grid Monitoring Architecture

• Registry

• Register/Search

• Register/Publish

• Bind

• Producer

• Consumer

• Events

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jGMA Implementation

• jGMA has the following components
• A Producer and Consumer (shared code-base),
• A Mediator which provides WAN access to producers
  and consumers and hooks for a resource discovery
  service (which we call the Virtual Registry).
• jGMA features
• Written in Java (taking advantage of usual
  features and libraries),
• Small programming interface (API) of 15 calls,
• Released ready to run as a 28Kbyte download (you
  just need Java).

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jGMA Architecture
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The two parts of jGMA

• Message passing,
• Provides communication between Consumers,
  Producers and Mediators,
• Implemented first.
• Virtual Registry (resource discovery),
• Boot-strapping Joining the jGMA network with
  minimal hardwiring,
• Communications Efficient routing of queries
  between jGMA Virtual Registries,
• Caching Keeping a temporary local copy of some
  information to reduce the amount of
  communications between peers.

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Optimising Message Passing

• Benchmarks to measure
• 1. Latency (time to send messages),
• 2. Bandwidth (throughput of messages),
• 3. Scalability (performance under load).
• Comparing with NaradaBrokering
• NaradaBrokering has a very similar architecture
  to the message passing part of jGMA,
• With the help of Raz we have measured latency and
  bandwidth for jGMA and NaradaBrokering.
• Results in a paper submitted to the Grid Workshop
  of Super Computing 2005.

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Initial Virtual Registry

• Investigating whether we can build a jGMA VR
  service using the mature Internet Relay Chat
  (IRC) protocol,
• The first IRC network was set up in 1988,
• IRC servers are connected in a way to attempt to
  efficiently route messages and provide fault
  tolerance,
• Some networks manage thousands of users.
• IRC can provide bootstrapping and communications.

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IRC VR Schematic
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Current Status

• Message passing layers complete,
• The initial implementation of the IRC VR is
  complete and functional,
• Demo applications and benchmarking has thoroughly
  tested the jGMA software,
• Permanent on-line demo
• http//dsg.port.ac.uk/projects/jGMA/demos/web/

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Webcam Browser Demo

• http//dsg.port.ac.uk/projects/jGMA/demos/web/

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Future Work

• Short term
• Implement a generic caching service for the VR,
• Add hooks for debugging,
• Longer term
• Provide a updated binary release of jGMA,
• Develop an application or library that uses
  jGMA.

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Summary

• jGMA is functional despite a few missing
  features,
• Current work is focusing on the implementation of
  the VR,
• The design of the jGMA architecture is complete.

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Links

• Project Web page
• http//dsg.port.ac.uk/projects/jGMA/
• The DSG Web page
• http//dsg.port.ac.uk/