OMII Release 1
Steven Newhouse, Peter Henderson
Stephen Crouch & Karen Ng
Presented by Mike Mineter for the
NGS Induction Course
http://www.omii.ac.uk
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The slides in this presentation were selected
and (in a few cases) modified by Mike
Mineter (NeSC) from those presented in
January 2005 at an OMII training day
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Goal of this presentation: to raise awareness
of the OMII and its OMII_1 release
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Outline
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OMII
The OMII_1 release: is available for
download
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TRY IT !!!
It is easy to use, although its grid middleware…
The ETF is currently assessing OMII_1 for
deployment on the NGS…. So watch for news!
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Open Middleware
Infrastructure Institute
OMII goal: to be the source of open source grid
software
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Institute of the University of Southampton
Utilise existing software and standards
Production focused software development
Integrate, test & document ‘a product’
Focus on the user experience
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Easy to install & use
Utilise existing software and standards
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Provide a solid web service base for others to build on
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Where does our software come
from?
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Open Source Community
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Software Repository
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Tomcat, Axis, etc.,
Accept software contributions
Software deployed, tested & graded to provide
feedback
Managed Programme
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Fill gaps to build a solid enabling infrastructure
Projects to bring research software to production
quality
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Managed Programme
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GridSAM (Job Submission & Monitoring service)
BPEL (Workflow service)
Grimoires (Registry service based on UDDI)
FIRMS (Reliable messaging)
FINS (Notification)
GeodiseLab (Matlab toolbox)
WSRF::Lite integration
OGSA-DAI (Database service)
WSeSS (Using SSH to tunnel requests to resources)
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OMII_1 release
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OMII_1:
A basic File-Compute Grid
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Enables a generic computational task
Move input data from the client to the service
provider
Process the data using an application on the
service provider
Retrieve the output data from the service
provider
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OMII_1 as a Service Provider
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Goal: I want others to access my resources &
applications
I want to provide secure controlled access to:
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My applications:
 Specify who can access which applications
My computational resources:
 I can limit external usage of my resources
Provides an interface that allows remote users to
access my resources
Enable collaboration with other partners
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OMII_1 as a User (or Client)
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Goal: I want to use other resources & applications
Through a network of service providers I can…:
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Gain access to applications that I do not have installed locally
Use remote machines with more CPU, memory or storage
 Process larger problems sizes
Transparently switch between different service providers
 No exposure to underlying OS, queuing policy, disk layout etc.
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Grid Architecture Today
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The best way of designing Grids…
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The best way of running Grids…
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Loosely coupled services
Message based exchange
Interoperability between versions & grids
Standards for infrastructure & services
The best way of building Grids…
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Leverage existing infrastructure & standards
Use Web Services…
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Some Web Service Definitions
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A service is the logical manifestation of some
physical or logical resources (databases, programs,
devices, humans, etc) and/or some application logic
that is exposed to the network
Service interaction is facilitated by message
exchanges
A service is an abstract resource that represents a
capability of performing tasks that represents a
coherent functionality from the point of view of
provider entities and requester entities. To be used,
a service must be realised by a concrete provider
agent
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Web Services (WS)
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XML: Platform neutral mechanism to describe
data
SOAP: Mechanism to describe message
exchange
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Simple Object Access Protocol
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Service Oriented Access Protocol
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Not simple and nothing to do with Objects!
Re-engineering of acronym to fit current use!
WSDL: Defines the service interface
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More WS concepts…
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Services have to reside in a supporting environment:
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Called: hosting environment or container
Marshals requests into and response out of the service
Service can discover local configuration parameters
Provides a standard infrastructure for service developers
Processing incoming requests & outgoing responses
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Called: Message handlers
Manipulates elements of the message header
 Primarily the SOAP header
Handlers can be applied to message traffic into or out of
the whole container or a specific service
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Putting it all together…
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Architecturally web services provide…
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Process of independent loosely coupling services
Defining service interfaces (or contract)
Defining the format of the messages interchange
Platform neutral
Flexible granularity
Clearly defined boundaries
Need an implementation…
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OS Hosting Environment
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Tomcat: Servlet hosting environment
Axis: A servlet that understands WS
Tomcat
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Axis Handlers
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Tomcat manages transport: http & https
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Axis handlers on client & server:
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OMII can use https to secure message transport
Serial / deserialisation from XML to Java
Processing of message headers
OMII distribution includes handlers for:
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WS-Security: sign message & verify signature
PBAC: Process Based Access Control
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Process Based Access Control:
A model for implementing AAA
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Authentication: CA issued X.509 certificates
Authorisation: Interaction dependent authorisation
process
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Access control lists tied to process context and state
 i.e. impose server side workflow requirements
Supports “delegation” and “subordination” actions
Accounting: Activity matched against allocated quota
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Clients control who can access “their” allocated quota
Collaboration with minimal overhead for service providers
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OMII 1:Basic File-Compute Grid
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Consists of:
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Base (Tomcat 5.0.25 & Axis 1.2b)
Extensions (Axis Handlers)
 WS-Security
 Process Based Access Control
Basic Services
Sample application
Plus installers, README’s & documentation
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OMII-1 Architecture
Management
(Browser)
Admin
Application
database
of
accounts
resources
applications
WS Security
PBAC
Web Services
resources
Accounting
Client
Application
Resource Mgmt
Data Staging
computation
data storage
applications
Application
Application
Job Submission
Application
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Tomcat & Axis
OMII 1:Basic Services
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Based on a group of four services
Functional: Data & Application execution
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Running jobs using pre-installed applications
Movement of input and output data files
Management: Account and Resources
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Must have an account with a service provider
Or delegated access to someone else’s account
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OMII Server Infrastructure
PBAC
ExampleService
TestService
Job
Data
Allocation
Account
Resource Acct
Mgmt
Mgmt
Servlet Servlet
Happy
Axis
WS-Security
AXIS
Static Webpage
TOMCAT
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Condor or PBS
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Job service supports execution on different platforms:
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PBS uses POSIX batch scheduling interface
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Local resources (default & fully tested)
Condor (demonstrated but not fully tested or supported)
PBS (demonstrated but not fully tested or supported)
Porting to other POSIX systems (e.g. SGE) should be
straightforward!
Demonstration only as the test servers do not have
Condor or PBS
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Try out the OMII_1 client !
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OMII_1 Download
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Contents:
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Server side installer (Application)
Client side installer
Cauchy Horizons
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Simple Java application
Transforms a surface (list of 3D points)
Install the client and use the OMII demo
server to run the Cauchy application
[Then set up your own server]
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Where to get the client
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Register at www.omii.ac.uk & login
Goto the downloads page
Download the client distribution
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SuSE 9.0
 Client may work on other Linuxs but no exhaustive testing
Windows XP (SP 1 & 2)
Distribution requires JDK 1.4.2_04
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Does not work with ‘just’ a JRE
Will not work with JDK 1.4.2_05/06 & JDK 1.5.0
No testing with earlier JDKs.
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Some notes on the certificate
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A certificate is needed on the client (WS-Sec)
Details passed to the OMII CA
Provides a certificate of low value
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No authentication checks
Expires after a month
Values are not verified
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Any non-null input will be OK
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Testing the installation
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Three tests at the end of the installation
All will fail if the container is not up & running
OR
If you have no connection to the test servers
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Checking the client install
CLIENT
testservicesConnection
PBAC
PBAC
ExampleService
TestService
Job
Data
Allocation
Account
Resource Acct
Mgmt
Mgmt
Servlet Servlet
non_PBAC
Happy
Axis
WS-Security
AXIS
Static Webpage
TOMCAT
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Summary
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WS provide an effective mechanism to build
loosely coupled message based systems
WS exchange XML messages over http/https
OMII_1 uses WS to provide a basic File &
Compute Grid
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Support
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Web: http://www.omii.ac.uk
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Follow links  Downloads  Feedback
Email: support@omii.ac.uk
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