Agreement-based Distributed
Resource Management
Alain Andrieux
Karl Czajkowski
Overview
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

The Resource Management Problem

Decentralized resource coordination

Resource owner goals vs. application goals
An Open Architecture to Manage Resources

Agreement-based negotiation model

Several scenarios
WS-Agreement (GGF GRAAP-WG)

Status: work in progress

Agreements using OGSI concepts
OIGS, Edinburgh
WS-Agreement
2
Distributed Resource Management
1. Discovery
“What resources are relevant to interest?”
 Finds service providers

2. Inspection
“What’s happening to them now?”
 Compare/select service providers

3. Agreement
“Will they provide what I need?”
 The core Resource Management problem

…Process can iterate due to adaptation
OIGS, Edinburgh
WS-Agreement
3
Social/Policy Conflicts
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Resource Consumers/Applications Goals
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Users: deadlines and availability goals
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Applications: need coordinated resources
Localized Resource Owner Goals


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Policies distinguish users
Community Goals Emerge As:

Global optimization goals

aggregate user/application and/or resource
Reconcile demands via Agreement
OIGS, Edinburgh
WS-Agreement
4
Early Co-Allocation in Grids
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
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SF-Express (1997-8)
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Real-time simulation
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12+ supercomputers, 1400 processors
Required advance reservation

Brokered by telephone!
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Practical use requires automation
Complex fault environment
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Over 45 minutes to recover from failure
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Reservations cannot prevent faults
OIGS, Edinburgh
WS-Agreement
5
Traditional Scheduling
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Closed-System Model
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Presumption of global owner/authority
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Sandboxed applications with no interactions
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“Toss job over the fence and wait”
Utilization as Primary Metric

Deep batch queues allow tighter packing
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No incentives for matching user schedule
Sub-cultures Counter Site Policies
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Users learn tricks for “gaming” their site
OIGS, Edinburgh
WS-Agreement
6
An Open Negotiation Model
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Resources in a Global Context
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Advertisement and negotiation
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Normalized remote client interface
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Resource maintains autonomy
Automated Agents Bridge Resources
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Drive task submission and provisioning
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Coordinate acts across domains
Community-based Mediation
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Agents coordinating for collective interest
OIGS, Edinburgh
WS-Agreement
7
Community Schedulers
J1
J2
J3
S1
J4 J5

S2
??
J1
J2
J3
J4
J5
R1
R2
R3
R4
R5
R6
OIGS, Edinburgh
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
Individual users
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Require service

Have application goals
Community schedulers
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Broker service

Aggregate scheduling
Individual resources

Provide service to clients

Have policy autonomy
WS-Agreement
8
Intermediaries And Policy
Client
Application
User Policy

advertise Resource
request
request
respond
respond
Scheduler
Community Policy
Manager
control
Resource
Resource Policy
Resource virtualization can:



advertise Community
Abstract details of underlying resource(s)
Map between different resource description domains
Policies from different domains influence
agreement negotiations with intermediaries
OIGS, Edinburgh
WS-Agreement
9
Heterogeneity of Service

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Many Kinds of Task
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Data: stored file, data read/write
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Compute: execution, suspended job
Many Kinds of Resource


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Hardware: disks, CPU, memory, networks,
display…
Capabilities: space, throughput…
Coordination Problem is much the same
OIGS, Edinburgh
WS-Agreement
10
Specialization: File Transfer

J1


S1
J2
Single goal
J3
Reliable deadline transfer
Specialized scheduler

Brokers basic services
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Synthesizes new service
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
R1
OIGS, Edinburgh
R2
R3
Fault-handling logic
Distributed resources
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Storage space
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Storage bandwidth
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Network bandwidth
WS-Agreement
11
Technical Challenges

Complex Security Requirements

Global Scalability

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Similar ideals to Internet
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Interoperable infrastructure

Policy-configurable for social needs
Permanence or “Evolve in Place”
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Cannot take World off-line for service
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Over time: upgrade, extend, adapt

Accept heterogeneity
OIGS, Edinburgh
WS-Agreement
12
WS-Agreement Components
Agreement Provider 1
Agreement
Initiator 1
AgreementFactory
(negotiate)
(monitor)
Agreement 1
Appl. Service 1
Agreement 2
Policy
(invoke)
Consumer 1
OIGS, Edinburgh
Application Service Provider 1
WS-Agreement
13
WS-Agreement Model
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Generic/extensible negotiation model
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Agreement wraps domain-specific terms

Agreement supports extensible monitoring
Reuse OGSI mechanisms

Specializes ogsi:Factory pattern
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Flexible lifetime negotiation for Agreements
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ServiceData for monitoring/introspection
OIGS, Edinburgh
WS-Agreement
14
Negotiation Interfaces

AgreementFactory
Persistent service
 Ex: façade to scheduler(s)
 Creates Agreement services


Agreement
Transient service
 Ex: job entry virtualized into a service
 Encapsulates state of negotiation



Terms, service status, relationship to other Agreements
Lifetime maps to lifetime of “terms of service”
OIGS, Edinburgh
WS-Agreement
15
Two-level Negotiation

AgreementFactory::createService()
Coarse-grained
 Conventional fault/response model
 Batch negotiation of complex terms
 Idiom: enables one-shot job submission


Agreement::renegotiate()
Fine-grained
 Allows complex multi-message negotiation
 Admits adaptation of provisioning terms

OIGS, Edinburgh
WS-Agreement
16
Agreement-based Jobs
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Agreement represents “queue entry”
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Commitment with job parameters etc.
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Job structure
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Wide range of QoS guarantees
Point for monitoring/control of job
Service is the Job computation
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Agreement-specific computation

May or may not communicate with clients
Advance Reservation is “pre-agreement”

Facilitates future job negotiation
OIGS, Edinburgh
WS-Agreement
17
Agreement Terms
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Real Agreements mix-in domain terms

Composed by logical grouping

Combined with negotiability mark-up
Each domain term brings a semantics

Unambiguous service-provisioning concept

Y=“amount of RAM allocable to process”
Agreement contextualizes domain term

(Y > 512 MB) AND (Y < 1024 MB)
OIGS, Edinburgh
WS-Agreement
18
The End

WS-Agreement is just beginning
GRAAP-WG at GGF
 Work on core negotiation model
 Work on reusable term meta-language


Domain Terms needed
Job submission
 Data management
 Accounting/Economic trading?
 …

OIGS, Edinburgh
WS-Agreement
19