The CoABS Grid: An Overview
Brian Kettler, Ph.D.
ISX Corporation
[email protected]
11 January 1999
OMG Agent Working Group Meeting
B. Kettler, ISX (1/99) 1
Agenda
• Brief overview of CoABS program
– Caveat 1: Views are mine, not DARPA's (etc.)
– Caveat 2: Program is young (6 months) and still
evolving… (more will be known after late January
workshop in Las Vegas)
– Caveat 3: Program just beginning to reach out to wider
community (FIPA, OMG, etc.)
• Overview of “The Grid”
– Caveat 4: Very much a “Work in Progress” (2-3 months
old)
– We need input!
B. Kettler, ISX (1/99) 2
The DARPA Control of Agent-based
Systems (CoABS) Program
• Goal: research/develop agent technologies supporting:
– semantic interoperability among heterogeneous agents
• efficient interagent communication at level of goals/tasks,
problem/domain elements (shared context, intent, etc)
• dynamic (run-time) collaborator discovery and cooperative
problem-solving behavior (dynamic teams, etc.)
• greater levels of autonomous action (taskability, adaptability, etc.)
• easier integration of software components (including agents, legacy)
– large scale multiagent systems
• many agents of varying sophistication/complexity on large scale,
real-world problems in dynamic, uncertain environments
• exploitation of parallelism
• efficient use of resources
• avoidance of chaotic behavior
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CoABS Program Organization
• Government
– PM: Prof. James Hendler (DARPA Information
Systems Office)
– Mr. Rick Metzger (USAF Research Lab/Rome)
• Potential Customers
– AMC, Other DARPA programs (ALP, etc.), ??? (TBD)
• Integration Contractor
– Global Infotek, Inc. (GITI)
– ISX Corporation
• Research Groups (university and industry) (~20)
B. Kettler, ISX (1/99) 4
CoABS Researchers
Effort
Agent-Ility
Agents for Plan Management
AgentTalk
Agentware
BORG
Group
OBJS
USC/ISI
OGI
Kestrel
CMU
Grid Integration
GITI/ISX
Coordination and Control using
Decision Theoretic Models
D’Agents
ERA
exception handling
JumpStart
MACOE
Multicast Protocols
RETSINA
Solution Clusters
UBC
SRI
Stanford
Dartmouth
Crystaliz
MIT
Boeing
Lockheed Martin
BBN
CMU
U.Oregon/CIRL
Team Leader
BBN
Teams of Auton. Cooperative,
Adaptive Agents
TEAMCORE
TRAC
TRIPS
CMU
USC/ISI
SRI
U. Rochester
PI
Craig Thompson
Craig Knoblock & Steve Minton
Phil Cohen
Doug Smith & Stephen Westfold
Pradeep Kholsa, Sebastian Thrun, Han
Kiliccote
Doyle Weishar, Brian Kettler,
Craig Boutilier,
Moises Goldszmidt,
Yoav Shoham
David Kotz, George Cybenko
Sankar Virdhagriswaran, Ellis Cohen
Chris Dellarocas, Mark Klein
Jeff Bradshaw et al
Ken Whitebread
Mark Fausett
Katia Sycara
Brian Drabble,
David Etherington,
Matt Ginsberg
Mark Burstien, Alice Mulvehill, Stephen
Deutsch, Drew McDermott
Manuela Veloso
Milind Tambe & Wei-min Shen
Adam Cheyer, David Martin, Karen Myers
James Allen,
George Ferguson
B. Kettler, ISX (1/99) 5
CoABS Program Efforts
• Technology Integration Experiments (TIEs)
– Operationally-focused TIEs
• 3 for late Spring 1999
• existing components/architectures (OAA, RETSINA, Prodigy,
etc.)
• NEO (Noncombatant Evacuation Operation) scenario
– Scientific TIEs
• experiments on control, scalability, etc.
• The Grid
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The Grid: Broad Vision
• A Scenario [by Paul Cohen & CoABS Steering Cmte]
– You are an infantry battalion commander who connects
your PDA online...
– Your personal assistant agent connects to the Grid
• tells Grid your physical location, current tasks/goals/plans,
resources, capabilities, needs, etc.
– Meanwhile, the Grid adjusts to you...
• i.e., can take advantage of your extra resources (physical, computer,
etc.) & capabilities:
– sends you the latest status reports relevant to your goals/interests
– run a meteorological simulation on some of your battalion PCs
– due to your expertise in Arabic, sends you documents to translate
• Grid resources, priorities, and goals adjusted dynamically
– When you (temporarily) disconnect from Grid...
• it prepares for your return (generates reports, filters email, etc.)
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The Grid
• The Grid is an infrastructure supporting the
semantic interoperability of agent groups, each
with potentially different agent architectures
•e.g., A group of OAA
agents talking to a
group of RETSINA
agents
Agent
Group B
(RETSINA)
Agent
Group A
(OAA)
GA
GA
GA
•Analogous to the
Internet’s support for
interoperability among
networks with different
protocols
GA
Agent
Group C
(OAA)
GA
GA
GA
GA
GA
Agent
Group D
(other)
GA
GA = Grid-aware Agents
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Grid Development Approach
• GITI/ISX is coordinating this effort
• Define Vision for Grid
– define operational scenarios for its use
• Define Requirements - top down approach
– define basic set of use cases (later expand for different
kinds of applications - e.g., planning agents)
– define minimal services Grid must have - produce
service-level description (message syntax/semantics)
• Define Requirements - bottom up approach
– canvass community (initially CoABS but also wider)
– look at existing agent services
• e.g., CMU’s RETSINA, Dartmouth’s D’Agents, SRI’s OAA
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Grid Development Approach (cont’d)
• Design/Develop Prototypes
– build something (and they will come…)
• a strawman versus waiting on the definitive specification
• initially implement base subset of use cases
• deploy and let community experiment with it
– multiple implementations of a service are desirable
– enumerate design assumptions & issues
• many are open research problems!
• Enumerate additional requirements
– from operational/functional TIEs, scientific TIEs
– incrementally refine, replace, update service
specifications and implementations
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Some Initial Simplifying Assumptions
• Focus on functionality, vs. performance
– “Real” Grid must consider fault tolerance, failure
recovery, comm bandwidth, CPU cycles, etc.
– scalability will be paramount
• Keep it simple (at least for now)
– define a minimal set of Grid services
• agent communities also will have their own services
– define a minimal set of messages an agent on the Grid
must support
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Use Cases
• Actors
– Users
• Application End User
• Grid/System Administrator
– Agents
• Grid-Aware Agents - can join the Grid
– Application Agents (problem solvers, resource mgrs., interface
agents)
– Grid Service Agents (Registration Agent, Security Agent, etc.)
• Non Grid-Aware Agents
• System
– The Grid
• Grid Services (Agents)
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Use Cases for Any Grid-aware Agent
(GA)
• Most basic:
–
–
–
–
–
GA connects to Grid
GA disconnects from Grid
GA posts request/need to Grid
GA posts capability/service advertisement to Grid
GA asks/requests another GA (i.e., direct agent-agent
comm)
• Additional use cases:
–
–
–
–
GA makes log/checkpoint entry
GA sets/clears timer
GA gets a security “check”
???
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Grid Registration Agents (GRAs)
• Map Grid ID of GAs to their address
– I.e., naming/white pages service
• Store addresses of some (local?) GAs
– DNS-style address scheme?
• Assign new Grid IDs to new GAs
– globally unique, persistent IDs
• Communicate with other GRAs
• Check GAs credentials, permissions, etc. with
Grid Security Agent
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Grid Matchmaker Agents (GMMAs)
• Map capabilities/services to IDs of GAs
– i.e., yellow pages service
• Store capability descriptions (i.e, ads)
– need some language for these (vocabulary -> ontology)
• Have query capability (e.g., nearest neighbor
matching, etc.)
• Communicate with other GMMAs
– organized hierarchically? by topic (or location)?
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Grid Management Agents (GMAs)
• Support management of Grid by agents and users
• Provide Grid status (to other agents)
– Grid comm infrastructure (i.e., network sensing)
– Can obtain status info from other GAs
– status info can be sent to Grid Visualization Services
(i.e., interface agents on the Grid)
• Detect problems
– deadlock, livelock, etc.
• Can exert control over GAs
– request they start/stop/suspend, etc.
• Can startup/shutdown other GSAs
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Other Grid Service Agents (GSAs)
• Grid Event Management Agents
– support setting/clearing timers
– may support other kinds of events (and possibly
triggers/sentinels)
– keep GMT (Grid Mean Time)
• Grid Logging Agents
– store activity/state info for GAs
– support querying of this info for debugging,
visualization, etc.
• Grid Security Agent
– provide authentication, access control, etc.
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Other Potential Grid Services
• Mobility
– support transport of running agents
– interface with control services for load balancing, etc.
• Exception Handling
– handling of common exceptions
– reduce burden on agent programmer
• Programming Tools
– facilitate construction of Grid-aware agents
– e.g., wrapping legacy agents and non-agent
components, debugging, etc.
B. Kettler, ISX (1/99) 18
Some General Design Issues
• Services provided by Grid (versus elsewhere)
– also customizability via policies, tuning, etc.
• Grid Comm (messaging infrastructure, ACLs, etc.)
– e.g., sockets or some higher level messaging mechanism
(RMI, CORBA, etc.)
– e.g., one or several mechanisms/ACLs supported
• GA-to-GA, GSA-to-GSA, etc.
• translation services provided?
– consider platforms, footprint, COTS software required, etc.
– lightweight vs. heavyweight ACLs (vocabulary vs.
ontology)
• Built-in (vs. add-on) support for mobility, security,
fault tolerance/recovery, etc.
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What We Need (1)
• Additional use cases
– higher-level/more specific?
• e.g., planner requests sentinel agent to monitor for threats to
plan
• Refinements on service-level descriptions of Grid
• Components to leverage for services
– other CoABS and non-CoABS agent services
– other services? (CORBA trader, event, etc.)
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What We Need (2)
• Agent communication mechanisms
– low-level messaging mechanisms (e.g., sockets,
CORBA, etc.)
– wrapper language (e.g., KQML-Lite, etc.)
– content language (e.g., KIF, etc.)
– ontology, service description language
• HPKB upper level ontology, etc.
• Agent Visualization techniques/tools
–
–
–
–
for debugging, demonstration, etc.
low-level activity (comm level, CPU, etc.)
comm content, patterns, etc.
higher-level activity (teams, subproblems, etc.)
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Additional Information
• CoABS
– http://dtsn.darpa.mil/iso/
• The Grid
– Use Case document
• email [email protected]
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