INFSO-RI-508833 Enabling Grids for E-sciencE Grid Services for Resource Reservation and Allocation Tiziana Ferrari Istituto Nazionale di

INFSO-RI-508833

Enabling Grids for E-sciencE

www.eu-egee.org

Grid Services for Resource Reservation and AllocationTiziana FerrariIstituto Nazionale di Fisica Nucleare, INFN CNAF

Terena Networking Conference, Poznan, June 6 2005


INFSO-RI-508833

Outline

• Use cases• The Grid Resource Allocation and Agreement Protocol• The EGEE gLite Agreement Service:

– Architecture– Components

• Workload Management System instrumentation• Implementation: the space reservation Agreement

Service prototype• Future work


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Grid Computing (2)

“A computational Grid is a hardware and software infrastructure that provides

dependable, consistent, pervasive and inexpensive access to high-end

computational capabilities”

Ian Foster, Carl Kesselman

• Purpose of Grid Computing: flexible, secure, coordinated resource sharing among dynamic collections of individuals, institutions, and resources

From “The Anatomy of the Grid: Enabling Scalable Virtual Organizations”


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Use Cases

• NETWORK: Data replication:

to optimize performance of a data transfer session (that otherwise would compete with other streams and would be subject to variable throughput)

to support file transfer with deadline (to synchronize job execution with input file transfer)

• COMPUTING: to reserve computing resources (e.g. worker nodes, CPU cycles) in

presence of a large number of other competing jobs• STORAGE:

to guarantee that a sufficient amount of space is present in a Storage Element to save the output data

the Storage Element is close to the Computing Element on which computing resources have been reserved


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• Use cases• The Grid Resource Allocation and Agreement Protocol• The gLite Agreement Service:





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• WS-Agreement defines a language and a protocol for– Advertising the capabilities of providers– Checking compliance to pre-defined templates– Creating agreements based on creational offers

• Agreement Layer:– Provides a web service based interface– represents and monitors agreements with respect to provisioning

of services implemented in the service layer• Service Layer (out of the GRAAP scope):

– is an resource-specific layer of a provided service– The interface to this layer is domain-specific: may or may not be

exposed as a web service interface

Grid Resource Allocation and Agreement Protocol – GGF GRAAP 2/2


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Grid Resource Allocation and Agreement Protocol – GGF GRAAP 1/2

Consumer Provider

create()

foo()Application Instance

Factory

Manager

create()Factory Agreement

Ops:terminate(limits)inspect(query)...SDEs:

Terms RelatedStatusAgrmts

inspect()

Agreement Layer

Service Layer

Consumer Provider

create()

foo()Application Instance

Factory

Manager

create()Factory Agreement

Ops:terminate(limits)inspect(query)...SDEs:

Terms RelatedStatusAgrmts

inspect()

Agreement Layer

Service Layer

WS-Agreement specification Conceptual Layered Service Model [2]

gLite Agreement Service

allocation and reservation service provider


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Agreement: XML structure

Agreement

Terms

Service Description Terms

Guarantee Terms

Context

Name

Name: identificator

Context: participants’ names, lifetime, links to otheragreements related to this (co-allocation)

Terms:

Service Description Terms:- provide information needed to instantiate and identify a service to which this agreement pertains- describes the functionality that will be delivered under an agreement

Guaranteed Terms:specify the service level that theparties are agreeing to

Terms are usage-domain independent.


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Agreement InitiatorAgreement Initiators

Agreement Offer

Storage/Computing/Network Agreement Service

Reservation and AllocationService Providers

The gLite Agreement Service 2/2


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The gLite Agreement Service 1/2• Agreement offer

– the “description” of the requested reservation• Agreement Initiator

– WMS Reservation Manager (reservation manager)– Data Scheduler– User

• Agreement Service– Checks offer compliance to one of theinternal templates– Can interact with several types of resource reservation service

providers (network – JRA4 bandwidth advance reservation, storage – StoRM, computing)

• Resource reservation Service Provider Enforces the reservation on a specific resource instance

• --> Full architecture described in [3]


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Agreement Service deployment

Reservation Manager (simple and co-allocation)

Agreement Offer_1

Logging &Bookkeeping

Agreement Service_1

Monitor_1

Reservation usageSensor_1

Service Provider_1

Workload Manager System

Agreement Offer

Agreement Service_n-1 Agreement Service_n

Agreement Offer_n-1 Agreement Offer_n

Resource

Monitor_1

Reservation usageSensor_1

Service Provider_1

Resource


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• One Service Provider instance per “resource” instance (e.g. CE and SE).

• manages resource availability information over time through a local “slot table”

• enforces resource reservation through resource-specific interfaces/for example:– Network:

the set of agents responsible of configuring switches/routers on a given path

– Storage: srmReserveSpace / srmReleaseSpace

• Monitoring of resource usage

Component 1. Service Provider


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Example: the JRA4 network Service Provider

“The Network Element should be seen as a set of services rather than a single component in the architecture . It provides user-oriented network services to the Higher Layer Middleware by abstracting the physical network services. Specifically it will allow reservation of network bandwidth and the definition of the desidered network QoS. This may involve mapping the the higher level service requests into network specific service requests.” [1]

Network Agreement Service

Network Service Provider


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Component 2. Agreement Service • Functionality:

– Interacts with one or more service providers– Translates high-level service description terms (from initiator) to low level service-specific

terms– Advertises the Service Provider capabilities through agreement templates. The template is

an XML document that describes the contract skeleton. – Handles the agreement negotiation (agreement offer attributes from the initiator are tuned

during the negotiation phase) – Provides information about: status of the agreement negotiation process and attributes of a specific

agreement instance

• Benefits:1. It hides the complexity of the service providers’ interfaces from the agreement initiator (the

client).2. It exposes a single operation which can be used independently of the nature of the

agreement type (createAgreement). 3. Scalability: new Service Providers can be easily integrated by advertising the

corresponding templates (clients can be notified when new templates are added).4. No need of a-priori knowledge about services available to users.


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Component 3. Agreement Initiator: the WMS Reservation Manager

• Reservation Manager: – a proposed component of the Workload Management

System (WMS) [4] which handles: Simple agreements (to start with) Compound agreements (next in development roadmap)

• Why integrated in the WMS?– Agreement offer submission: similar to job submission– Agreement status: information from Logging and Bookkeeping– Agreement Service discovery: a list of Agreement Services is

tried (more powerful than submission to a single Agreement Service)

based on matchmaking library takes advantage of the WMS internal cache

– Periodic re-submission in case of failure


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WMS instrumentation

UserInterface

AgreementOffer

Taskqueu

e

Match

Maker

ReservationManager

Cache (ISM)Cacheupdate

r

Logging and Bookkeeping

Reserv.Helper

Agr.offer + Resource list + Agr. Service EPR list

Web Service interface

Reserv.Cleaner


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WMS Agreement Service Discovery

• Problem: given an agreement offer including1. Resorce requirements2. Resource preferences (optional)3. Service functionalityfind Agreement Services that support service functionality (3) and can(indirectly) do reservation on resource instances satisfying (1) and (2)

• Matchmaking finds a list of resources: – on which user is authorised to do reservation and– satisfying resource requirements (1), preferences (2), and supporting (3)

• find Agreement Services:– authorized to talk to the resources in the list identified above– Supporting the corresponding allocation and reservation service provider

interfaces


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• Workload Management System instrumentation• Implementation: the storage space reservation

Agreement Service prototype• Future work


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Implementation 2/2

• Agreement service:– based on WS-Agreement XML Schema Definitions (GGF,

GRAAP WG)– ... but operations exposed are different (no Web Services

Resource Framework - WSRF)– gSOAP 2.7.0– agreement service tested with StoRM (SRM v 2.1)


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• Extension of the Workload Management System• Implementation: the storage space reservation

Agreement Service prototype• Future work


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Future work• Extension of the prototype's functionality set

– Improvement of error handling– Authorization– Study of deployment model– Implementation of new operations– Full integration with WMS– Agreement monitoring through LB

• Performance testing• Support of more Service Providers:

– Network– computing


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References• [1] Specification of interfaces for bandwidth reservation

service, EGEE deliverable DJRA4.1, May 2005 (http://edms.cern.ch/document/501154)

• [2] The Grid Resource Allocation and Agreement Protocol Working Group; Global Grid Forum (https://forge.gridforum.org/projects/graap-wg).

• [3] gLite Allocation and Reservation Architecture, EGEE JRA1 technical report (http://edms.cern.ch/document/508055)

• [4] EGEE Middleware Architecture; EGEE Deliverable JRA1.1(http://edms.cern.ch/document/476451)

http://edms.cern.ch/document/501154

http://edms.cern.ch/document/508055

Documents

INFSO-RI-508833 Enabling Grids for E-sciencE Grid Services for Resource Reservation and Allocation Tiziana Ferrari Istituto Nazionale di