Jini and the Grid

1
Jini and the Grid

• Dr Mark Baker
• Distributed Systems Group
• University of Portsmouth
• http//dsg.port.ac.uk/mab/

2
Outline

• Jini
• Overview,
• Architecture and operation.
• The Grid
• Overview,
• OGSA,
• Example applications.
• Possible Jini/Grid interaction
• Jini with the Grid,
• The Grid with Jini.
• Summary and Conclusions.

3
The Jini Architecture

• Why Jini and What is Jini?
• Jini technologies and architecture.
• Jini services
• Discovery,
• Lookup,
• Joining.
• Leases, Transactions and Events and Security.
• Summary.

4
A New(ish) Architecture

• Both hardware and software
• Everything is an object,
• Everything is accessed through an interface.
• Network and language centric
• Data and code come from the network,
• The Java language is assumed to be everywhere.
• Service-based architecture!
• Designed for the network
• Code and data move, as appropriate,
• Appropriate for everything
• Devices, large servers, software.
• Everything is an object
• Hardware and software provide services.

5
Philosophy

• Less is more
• The simplicity of object-oriented design,
• RMI extends objects to the network.
• Language-based system
• Java language forms a conceptual framework,
• No division between network and programming types.

6
Goals of the Jini System

• Enable spontaneous networking
• Plug in and join,
• Unplug and heal.
• Provide reliable networks
• Individual services more reliable,
• System independence from any single point of
  failure.
• Above all, simplicity

7
Extending the Java Platform
8
Jini is a distributed servicesarchitecture key
features

• A Discovery and Lookup Service
• Find things.
• Leasing
• Letting everybody know you are still there and
  interested.
• Distributed Events
• Finding out when things change.
• Transactions
• Trusting distributed interactions/events.
• Distributed, tuple-based store

9
Discovery and Lookup

• LUS provides a programming API and end-user
  access/repository.
• Directory services
• Unicast discovery (need to know where to find the
  service)
• LDAP/X.500, DNS, RMI Registry.
• Multicast discovery
• Transmit a multicast packet and wait for services
  to respond,
• Good up to multicast radius!

10
Basic summary

• Service perspective
• Register with desired attributes,
• Keep renewing lease,
• Add, modify, delete attributes as desired.
• Client perspective
• Lookup any one of, get just proxy object,
• Lookup up to N of, get proxies and attributes.

11
What Lookup Service Does

• Clients use the LU to find services.
• Services look for LU services and bind references
  of themselves to each one.
• The LUS can store any serializable object, Like
  LDAP.
• You look up things by type, not by name.
• The LUS automatically purges references to
  services that are bad
• Bad dead or failed to renew lease.
• The LUS is organized into groups
• Allows segregation of services such as by room,
  floor.
• Leaving a Jini federation
• Services can cancel LUS registration.
• A registration lease can run out.
• No administrator required.

12
Client/Service/LUS Operation
LUS
LUS
Client
2
4
1
3
Service
13
Why Distributed Leasing?

• Problem Partial failure in distributed systems
  can lead to unchecked resource consumption.
• Traditional solution system administration
• Error-prone,
• Costly,
• Only happens when it is too late.
• Leasing protocol for managing resources using a
  renewable, duration-based model.
• Contract between objects.
• Resources can be shared or private.
• Provides a method of managing resources in an
  environment where network failures can, and do,
  occur.

14
Distributed Events in Jini

• Enables Java event model to work in a distributed
  network.
• Register interest and then receive notification.
• Allows for use of event managers.
• Can use numerous distributed delivery models
• Push, pull, filter...
• Uses leasing protocol.

15
Transaction model in Jini

• Designed for distributed object coordination
  light weight, object-oriented.
• Supports
• Nested transactions,
• Various levels of ACID properties (Atomicity,
  Consistency, Isolation, Durability),
• Two-phase commit.
• Uses leasing protocol.
• Implemented in Transaction Manager service
  another Jini service (mahalo).

16
Security in Jini

• Security for Jini is based on the JDK 1.4
  security model.
• In Java a Security Manager is used to grant or
  deny access to resources.
• The security manager makes use of a security
  policy.
• Now using Java Authentication and Authorisation
  Services (JAAS).
• This is typically given in a policy file, which
  is stored in some default location or specified
  at runtime.
• New security features in Jini v2.

17
Summary

• Discussed Jini and how it tries to bridge the
  perceived problems with distributed systems.
• Looked at
• Lookup
• Registration and Discovery
• Leasing
• Events and Transactions
• Security.

18
The Brief Overview of the Grid
19
Enter Grid Technologies

• Infrastructure (middleware) for establishing,
  managing, and evolving multi-organisational
  federations
• Dynamic, autonomous, domain independent,
• On-demand, ubiquitous access to computing, data,
  and services.
• Mechanisms for creating and managing workflow
  within such federations
• New capabilities constructed dynamically and
  transparently from distributed services
• Service-oriented, virtualisation

20
Elements of the Problem

• Resource sharing
• Computers, storage, sensors, networks,
• Sharing always conditional issues of trust,
  policy, negotiation, payment, security,
• Coordinated problem solving
• Beyond client-server distributed data analysis,
  computation, workflow, collaboration,
• Dynamic, multi-institutional virtual orgs
• Community overlays on classic organisational
  structures (CERN for example),
• Large or small, static or dynamic.

21
The Emergence ofOpen Grid Standards
Increased functionality, standardisation
Custom solutions
1990
1995
2000
2005
2010
22
Open Grid Services Architecture

• Service-oriented architecture
• Key to virtualisation, discovery, composition,
  local-remote transparency.
• Leverage industry standards
• In particular, Web Services.
• Distributed service management
• A component model for Web Services
• A framework for the definition of composable,
  interoperable services

The Physiology of the Grid An Open Grid
Services Architecture for Distributed Systems
Integration, Foster, Kesselman, Nick, Tuecke,
2002
23
Web Services

• XML-based distributed computing technology.
• A Web service a server process that exposes
  typed ports to the network.
• Described by the Web Services Description
  Language (WSDL), an XML document that contains
• Type of message(s) the service understands and
  types of responses and exceptions it returns,
• Methods bound together as port types,
• Port types bound to protocols as ports,
• A WSDL document completely defines a service and
  how to access it

24
OGSI

• The OGSI specification defines the fundamental
  concepts and characteristics of Grid Services.
• It introduces the concept of a Grid Service
  Instance a Web Service that conforms to a set
  of conventions (interfaces and behaviours) and
  adds features including
• Statefulness
• Stateful interactions
• The ability to create new instances
• Service lifetime management
• Notification of state changes service groups.
• It is these additional features that define the
  semantics of Grid Service Instances, the
  foundation of the Grid infrastructure.

25
Grid Requirements

• The key requirements for a Grid Application
  Framework which are crystallised in the current
  OGSI specification are to provide consistent
  mechanisms for
• Stateful interactions between consumers and
  services,
• Exposure of a Web Services publicly visible
  state,
• Access to (possibly large amounts of)
  identifiable data,
• Service lifetime management,

26
Grid Evolution OGSA

• Re-factor Globus protocol suite to enable common
  base and expose key capabilities.
• Service orientation to virtualise resources and
  unify resources/services/information.
• Embrace Web Services technologies for standard
  IDL and leverage from commercial efforts.
• Result standard interfaces and behaviour for
  distributed system management the Grid Service.

27
GT3 Open Source OGSA Technology

• Implements and builds on OGSI interfaces.
• Supports primary GT2 interfaces
• Public key authentication,
• Scalable service discovery,
• Secure, reliable resource access,
• High-performance data movement (GridFTP).
• Numerous new services included or planned
• SLA negotiation, service registry, community
  authorization, data access integration,
• Rapidly growing adoption and contributions
• E.g., OGSA-DAI from U.K. e-Science programme.

28
Example Applications
29
Multi-disciplinary Simulations
Wing Models

• Lift Capabilities
• Drag Capabilities
• Responsiveness

Stabilizer Models
Airframe Models

• Deflection capabilities
• Responsiveness

Crew Capabilities - accuracy - perception -
stamina - re-action times - SOPs
Engine Models

• Braking performance
• Steering capabilities
• Traction
• Dampening capabilities

• Thrust performance
• Reverse Thrust performance
• Responsiveness
• Fuel Consumption

Landing Gear Models
30
UK e-Diamond Project
Tele-radiology and QC VirtualMammo
Training and Differential Diagnosis Find one
like it
?

Advanced CAD SMF-CAD workstation
Epidemiology SMFcomputed breast density
31
Online Access to Scientific Instruments
Advanced Photon Source
wide-area dissemination
desktop VR clients with shared controls
real-time collection
archival storage
tomographic reconstruction
DOE X-ray grand challenge ANL, USC/ISI, NIST,
U.Chicago
32
Data Grids forHigh Energy Physics
33
DAME
In flight data
Airline
Global Network e.g. SITA
Ground Station
DSS Engine Health Center
Maintenance Centre
Internet, e-mail, pager
Data centre
34
The 13.6 TF TeraGrid Computing at 40 Gb/s
35
Summary

• The Grid problem resource sharing and
  coordinated problem solving in dynamic,
  multi-institutional virtual organisations.
• Grid architecture emphasises systems problem
• Protocols and services, to facilitate
  interoperability and shared infrastructure
  services.
• Globus Toolkit APIs, SDKs, and tools which
  implement Grid protocols and services
• Provides basic software infrastructure for suite
  of tools addressing the programming problem.
• Globus is converging on the OGSA.
• Standards being defined by GGF, consisting of
  academic, industry and commercial bodies (more
  later).

36
An Example OGSA Application
37
Grid Services Example Data Mining
Community Registry
Mining Factory
Database Service
BioDB 1
Compute Service Provider
User Application
. . .
. . .
I want to create a personal database containing
data on e.coli metabolism
Database Service
Database Factory
BioDB n
Storage Service Provider
38
Grid Services Example Data Mining
Find me a data mining service, and somewhere to
store data
Community Registry
Mining Factory
Database Service
BioDB 1
Compute Service Provider
User Application
. . .
. . .
Database Service
Database Factory
BioDB n
Storage Service Provider
39
Grid Services Example Data Mining
Community Registry
Mining Factory
Database Service
GSHs for Mining and Database factories
BioDB 1
Compute Service Provider
User Application
. . .
. . .
Database Service
Database Factory
BioDB n
Storage Service Provider
40
Grid Services Example Data Mining
Community Registry
Mining Factory
Database Service
Create a data mining service with initial
lifetime 10
BioDB 1
Compute Service Provider
User Application
. . .
. . .
Create a database with initial lifetime 1000
Database Service
Database Factory
BioDB n
Storage Service Provider
41
Grid Services Example Data Mining
Community Registry
Mining Factory
Database Service
Create a data mining service with initial
lifetime 10
BioDB 1
Miner
Compute Service Provider
User Application
. . .
. . .
Create a database with initial lifetime 1000
Database Service
Database Factory
BioDB n
Database
Storage Service Provider
42
Grid Services Example Data Mining
Community Registry
Mining Factory
Database Service
Query
BioDB 1
Miner
Compute Service Provider
User Application
. . .
. . .
Query
Database Service
Database Factory
BioDB n
Database
Storage Service Provider
43
Grid Services Example Data Mining
Community Registry
Mining Factory
Database Service
Query
BioDB 1
Miner
Keepalive
Compute Service Provider
User Application
. . .
. . .
Query
Database Service
Database Factory
Keepalive
BioDB n
Database
Storage Service Provider
44
Grid Services Example Data Mining
Community Registry
Mining Factory
Database Service
BioDB 1
Miner
Keepalive
Compute Service Provider
User Application
. . .
. . .
Results
Database Service
Database Factory
Keepalive
Results
BioDB n
Database
Storage Service Provider
45
Grid Services Example Data Mining
Community Registry
Mining Factory
Database Service
BioDB 1
Miner
Compute Service Provider
User Application
. . .
. . .
Database Service
Database Factory
Keepalive
BioDB n
Database
Storage Service Provider
46
Grid Services Example Data Mining
Community Registry
Mining Factory
Database Service
BioDB 1
Compute Service Provider
User Application
. . .
. . .
Database Service
Database Factory
Keepalive
BioDB n
Database
Storage Service Provider
47
Summary

• The Grid problem resource sharing and
  coordinated problem solving in dynamic,
  multi-institutional virtual organisations.
• Grid architecture emphasises systems problem
• Protocols and services, to facilitate
  interoperability and shared infrastructure
  services.
• Globus Toolkit APIs, SDKs, and tools which
  implement Grid protocols and services
• Provides basic software infrastructure for suite
  of tools addressing the programming problem.
• Globus is converging on the OGSA.
• Standards being defined by GGF, consisting of
  academic, industry and commercial bodies (more
  later).

48
Possible Jini/Grid Interaction
49
Client/Service Interaction
50
Client/Service Interaction
51
Jini/GT2 Interaction

• Two interaction scenarios
• Direct heavyweight client
• Intelligent Client!
• Up-front knowledge of usage needed.
• Direct Jini/Grid usage.
• No intermediate broker.
• Indirect lightweight client
• Simple Client.
• Little up-front knowledge NOT needed.
• Indirect Jini/Grid usage.
• Intermediate resource broker.

52
Direct Interaction Grid-Jini
Jini Enabled
Jini
Grid
GIS
LUS
GIS/LUS Interface
Service Proxy
Grid Client
Service
53
Indirect Interaction Grid-Jini
Jini
Grid
LUS
GIS
Jini Enabled
LUS Interface
Resource Broker
Service Proxy
Grid Client
Service
54
Direct Interaction Jini - Grid
Jini
Grid
GIS
LUS
CoG Interface
Jini/CoG Enabled
Grid Service
Client
55
Indirect Interaction Jini - Grid
Jini
Grid
LUS
GIS
LUS Interface
Jini/Cog Enabled
Resource Broker
Grid Service
Client
56
Interaction with a Jini Service
Find
Publish
Jini Client
Service Registry
Lookup Service
Jini Service
Service Proxy
Bind/Invoke
57
Interaction with a Jini Service
Publish
Service Registry
UDDI registry
Jini Service
Find
WS Client
WSDL
Bind/Invoke
58
Interaction with a Web Service
Find
Publish
Jini Client
Service Registry
UDDI registry
Lookup Service
Web Service
UDDI proxy
WSDL
Bind/Invoke
59
Interaction with a Web Service
Publish
Service Registry
UDDI registry
Web Service
Find
WS Client
WSDL
Bind/Invoke
60
Grid Service Interaction
Find
Service Registry
UDDI registry
GS Client
Grid Service
Publish
GS Factory
MDS3
Bind/Invoke
GSH
61
Jini and Grid Service Interaction
Service Registry
Publish
Lookup Service
Find
Grid Service
Jini Client
Jini GSH
Bind/Invoke
62
Jini and Grid Service Interaction
Service Registry
Publish
Lookup Service
UDDI
Find
Grid Service
Jini Client
UDDI Proxy
WSDL
Bind/Invoke
GSH
63
Summary

• Looked at how various clients find services
• Jini client
• WS,
• GS
• Jini.
• WS Client
• Jini
• GS,
• WS.
• With Jini and GS, it is not clear exactly what is
  the best way for a client to interact.
• Need to consider factories, leases and security
  in more depth.

64
Overall Summary

• Looked at the main issues in creating an all-Jini
  Grid system.
• Looked at an example Grid system, its components,
  architecture and operation.
• Open problems include LUS hierarchy, QoS, user
  management, and checkpointing.
• Shown different demo programs using various proxy
  patterns, sequential and parallel execution on
  different services.

65
Conclusions

• Integrating Jini and the Grid together is useful
  for a number of reasons
• Proof of concept integrating two distributed
  environments with similar goals but radically
  different implementation details that are now
  converging with the adoption of WS.
• Increasing numbers of Grid and Jini-based
  environments and so the need for interaction is
  more and more likely.
• Issue raised are ongoing research efforts
  operating with Globus, Web Services, CORBA

66
Further Information

• http//www.dsg.port.ac.uk/mab/
• Email Mark.Baker_at_computer.org

67
For More Information

• Globus Project
• www.globus.org
• Grid Forum
• www.gridforum.org
• www.ggf.org
• Books
• Morgan Kaufman)
• www.mkp.com/grids

68
For More Information
http//www.wiley.com/WileyCDA/WileyTitle/productCd
-0470853190.html
69
Grid Service Resources

• OGSI documents
• www.gridforum.org/ogsi-wg
• OGSA documents
• www.gridforum.org/ogsa-wg
• Globus Toolkit v3 implementation
• www.globus.org

70
Acknowledgements

• Globus team.