Www.neresc.ac.uk A Dynamic Service Deployment Infrastructure for Grid Computing or Why it’s good to be Jobless Paul Watson School of Computing Science

www.neresc.ac.ukwww.neresc.ac.uk

A Dynamic Service Deployment Infrastructure for Grid Computing

orWhy it’s good to be Jobless

A Dynamic Service Deployment Infrastructure for Grid Computing

orWhy it’s good to be Jobless

Paul WatsonSchool of Computing ScienceUniversity of Newcastle, UK

Paul WatsonSchool of Computing ScienceUniversity of Newcastle, UK

Thanks: Chris Fowler, Charles Kubicek, Arijit Mukherjee, John Colquhoun, Savas Parastatidis, Mark Hewitt, Isi Mitrani, Jennie Palmer, Rob Smith, Paul McKee & Mike Fisher

www.neresc.ac.ukwww.neresc.ac.uk 2

Data in Science

• Bowker’s “Standard Scientific Model”1

1. Collect data2. Publish papers3. Gradually loose the original data

1The New Knowledge Economy and Science and Technology Policy, G.C. Bowker, E1-30-03-05


Publishing data as well as papers

• e-Science is trying to change this to:1. Collect data2. Publish data & papers

e.g. SkyServer, OGSA-DAI publish databases through Web Services…

C

req

resAnalysis Service

DatabaseService

req

res


0

500

1000

1500

2000

2500

Tuples Requested

To

tal P

rocessin

g T

ime (

seco

nd

s)

Problem: Moving Data

C

req

resAnalysis Service

DatabaseService

req

res

• Databases are good at localising computation & data• But, often large amounts of data must still be transferred

• this may severely limit the performance


Jobs: the Grid Solution?

• Grid Computing offers remote job scheduling• Therefore, we could package the analysis code & data

as a job and send it to compute resources close to the data

• We decided to explore an alternative…


Why Jobs & Services?

• Grid applications are being built from Web Services• But, if the computational requirements can’t be met

by the service hosting environment then a job must be created and scheduled

• Why do we need both jobs and services?

• Dynasoar• a service-only approach to building grid applications• an infrastructure for the dynamic deployment of web services


Web Services

C WS

req

res

Web ServiceConsumer


Dynasoar Components

• Web Service Provider (WSP)• exposes service endpoints• accepts the incoming SOAP message sent to the endpoint• chooses a Host Provider and passes the message to it• holds a copy of service code

• Host Provider (HP)• manages computational resources (e.g. a cluster or a grid)• accepts the message from the WSP• dynamically deploys the service if necessary• processes the message and returns any response

Consumer

C WSP HP

req

res

req

res


Routing to an Existing Service Deployment

C WSP

req

res

Host Provider

node 1s2, s5

…

node 2

node ns2

Web Service Provider

Consumer

A request for s2 is routed to an existing

deployment of the service


Dynamic service deployment

C WSP

req

res

1

Host Provider

node 1s2, s5

…

node 2

node ns2


3

2: service fetch &deploy

Consumer

R

The deployed service remains in place andcan be re-used - unlike job scheduling

A request to s4 cannot be met by an existing deployment of the service


Dynasoar Advantages

• Simplicity: just services• Efficiency: a deployed service can process many

messages• important if cost of deployment is high… e.g. VMs

• Support a range of new e-science/ e-business models:• defining the interactions between the major components

allows them to be distributed in a variety of ways


Dynamic Outsourcing

• Biocorp are experts in writing bioinformatics services• They don’t want to manage their own compute resources• Therefore, they use Hosting Inc to process messages sent to

their services

HPWSP

C

C BioCorp Hosting Inc

…..

BioCorpCustomers


The National Grid Service as a Host Provider

• A researcher writes their own services but does not have sufficient local compute resources

• They deploy a local WSP, and configure it so that it sends messages to the National Grid Service• their services are then transparently deployed on the NGS as

required

C WSP

National Grid

node …... node

Researcher’sLocal Resources

..node node

Quarantine Nodes


Brokers for Matching Web Service Providers to Host Providers

HP1WSP1

Broker

HPnWSPn

......

......

Web Service Providers

Host ProvidersSelection on:• Price,• Performance,• Dependability,…


A Broker for e-Science

HP1WSP1

Broker

HPnWSPn

......

......

Web Service Providers

Host Providers

LocalCampusGrid

NationalGridService


Moving Computation to Data

• The data owner provides compute resources close to a database• Researchers can write services and deploy them on their own

WSP• The service is dynamically deployed close to the database when

requests are sent to the WSP

C WSP

req

res

1

Host Provider

node 1

…

node 2

node n


offering the Analysis Service

3

2: service fetch &deploy

Consumer

Database Service

High PerformanceNetwork


Results for Deploying a Service Close to a Database


Tripartite Security Model

C HP

WSP

TRIPARTITETRUST

DOMAIN

The 3 actors can define policies (XACML) that Dynasoar enforces at run-time, e.g….

Accept only messagesfrom WSPs trusted to notsend malicious code

Only use Host Providers trusted to not re-use the deployed service without payment

Only send the message to a HP trustednot to look at the contents


Service Provider

QoS Policies

Deployed Service Registry

Web ServiceCode Store

Host Provider

Code Store SOAP interface

Security Policies

SOAP Endpoints

Message Handler

Computational resourcesHosting deployed services

Host Provider Registry

DynasoarHost Provider

Interface

Host Provider Endpoint

Service ProviderEndpoint

Current Implementation

GridShed ClusterManagement

(includes algorithmto decide when todeploy extra copiesof a service to meetperformancerequirements)


New Host Provider Architecture

• Layer as high-level infrastructure over lower level grid fabric• Use OMII Job Submission and Monitoring Service to provide

stable interface to different underlying fabrics• Newcastle Grid (Condor), National Grid Service, local clusters,….

Host Provider

Grid Fabric

DynasoarHost Provider

Interface

OMII Job Submission and Monitoring Service

(Grid-SAM)


Dynamic Service Grids

Broker

WSP

HPHP

C

HPHP

Broker

WSP

C

HPHP

Service Repository

Service Repository

Key to success: the availability of services for deployment


Active Information Repository

Data

Metadata

Service 1

Service 2

Service n

Fixed Services

Service 1

Service 2

Service n

Dynamically Deployed Services

in Host Provider

Workflow Enactment

Engine

Active Information Repository

Client

Client

..............


Current Work

• Experimenting with Bioinformatics Services• Deploying Services in Virtual Machines

• can encapsulate a complex service implementation environment

• Use of QoS to guide decisions on where to deploy a service

• When and where to deploy within Host Provider?• GridSHED project

• Reproducible e-science


Conclusions

• Grid applications can be built entirely from services• jobless grid computing• simpler conceptual model• performance improvements due to sharing the cost of service

deployment over multiple requests

• Dynasoar is built as a high-level infrastructure on top of existing grid fabrics

• Separating the Web Service Provider from the Host Provider – with a well-defined interface – opens up a range of e-science/ e-business models

Documents

Www.neresc.ac.uk A Dynamic Service Deployment Infrastructure for Grid Computing or Why it’s good to be Jobless Paul Watson School of Computing Science