Transcript Web Services and Grid Architecture and their application to Earthquake Science USC AIST Meeting August 31 2004 Geoffrey Fox Community Grids Lab Indiana University [email protected].

Web Services and Grid Architecture
and their application to
Earthquake Science
USC AIST Meeting
August 31 2004
Geoffrey Fox
Community Grids Lab
Indiana University
[email protected]
Philosophy of Web Service Grids
• Much of Distributed Computing was built by natural
extensions of computing models developed for sequential
machines
• This leads to the distributed object (DO) model represented
by Java and CORBA
– RPC (Remote Procedure Call) or RMI (Remote Method
Invocation) for Java
• Key people think this is not a good idea as it scales badly
and ties distributed entities together too tightly
– Distributed Objects Replaced by Services
• Note CORBA was considered too complicated in both
organization and proposed infrastructure
– and Java was considered as “tightly coupled to Sun”
– So there were other reasons to discard
• Thus replace distributed objects by services connected by
“one-way” messages and not by request-response messages
Programs
Computational resources
service logic
BPEL, Java, .NET
Databases
SOAP and WSDL
• Web Services build
loosely-coupled,
distributed applications,
based on the SOA
principles.
• Web Services interact
by exchanging
messages in SOAP
format
• The contracts for the
message exchanges that
implement those
interactions are
described via WSDL
interfaces.
Humans
<env:Envelope>
<env:Header>
...
</env:header>
<env:Body>
...
</env:Body>
</env:Envelope>
SOAP messages
message processing
Web services
resources
Devices
What is a Grid?
• You won’t find a clear description of what is Grid and how
does differ from a collection of Web Services
– I see no essential reason that Grid Services have different
requirements than Web Services
– Geoffrey Fox, David Walker, e-Science Gap Analysis, June 30
2003. Report UKeS-2003-01,
http://www.nesc.ac.uk/technical_papers/UKeS-2003-01/index.html.
– Notice “service-building model” is like programming language –
very personal!
• Grids were once defined as “Internet Scale Distributed
Computing” but this isn’t good as Grids depend as much if
not more on data as well as simulations
• So Grids can be termed “Internet Scale Distributed
Services” and represent a way of collecting services
together to solve problems where special features and
quality of service needed.
e-Infrastructure



e-Infrastructure builds on the inevitable increasing performance
of networks and computers linking them together to support new
flexible linkages between computers, data systems and people
• Grids and peer-to-peer networks are the technologies that
build e-Infrastructure
• e-Infrastructure called CyberInfrastructure in USA
We imagine a sea of conventional local or global connections
supported by the “ordinary Internet”
• Phones, web page accesses, plane trips, hallway conversations
• Conventional Internet technology manages billions of
broadcast or low (one client to Server) or broadcast links
On this we superimpose high value multi-way organizations
(linkages) supported by Grids with optimized resources and
system support
• Low multiplicity fully interactive real-time sessions
• Resources such as databases supporting (larger) communities
N plus N Community Resources


Grid Community databases have analogy to Television and the
News Web that allow individuals to communicate instantly with
each other via Web Pages and Headline News acting as proxies
N resources deposit information and N can view  Call N plus N
Large and Small Grids






N resources in a community (N is billions for the world and 100010000 for many scientific fields)
Communities are arranged hierarchically with real work being
done in “groups” of M resources – M could be 10-100 in e-Science
Metcalfe’s law: value of network grows like square of number of
nodes M – we call Grids where this true Metcalfe or M2 Grids
Nature of Interaction depends on size of M or N
• N plus N Shared Information Grids for largish N
• M2 Metcalfe Grids for smaller M < N
Technology support depends on M/N – might use a relatively
static DHT (Distributed Hash Table) for large N and a distributed
shared memory for small M
Grids must merge with peer-to-peer networks to support both N
plus N and M2 Systems
M2 Interactions
• Superimpose M way
“Grids” on the sea
(heatbath) of “2 by N”
or N plus N
“ordinary”
interactions
Grids also support
many community
N plus N resources
Implement Grids
as a software
overlay network
Information Complexity I

Consider a community of N resources with groups of size
M with each group complexity C
• N/M Groups

Information in systems varies from coherent
(harmonious) to incoherent limits
• Web and Grid data resources supply coherence as in curated
astronomy, bioinformatics, geophysics database
• Can consider N plus N Grids as Coherent or Harmonious
Grids


I = (NM)0.5 . (C/M) Incoherent to N . (C/M) Coherent
In this language Grids do one or both of
• Coherence/Harmony – common shared asynchronous
resources
• Interactivity – Increase complexity to M2 with real-time
linkage of interacting resources
Information Complexity II




N plus N Community database has I = N Coherent
• Improving on N0.5 incoherent case
Nearest Neighbor groups is I = (NM)0.5
• Becoming I = N in limit M = N
• M is correlation length in Complex Systems approach
M-ary Interactive group (M2 Metcalfe Grids) has C = M2
and
I = (NM3)0.5 Incoherent
to I = NM Coherent
• Coherent case most natural in science due to synergy
between Metcalfe and Coherence Grids
“Small World (logarithmic) networks” and hierarchical
group structure require more discussion
Architecture of (Web Service) Grids



Grids built from Web Services communicating through
an overlay network built in SOFTWARE on the
“ordinary internet” at the application level
Grids provide the special quality of service (security,
performance, fault-tolerance) and customized services
needed for “distributed complex enterprises”
We need to work with Web Service community as they
debate the 60 or so proposed Web Service specifications
•
•
•
•
Use Web Service Interoperability WS-I as “best practice”
Must add further specifications to support high performance
Database “Grid Services” for N plus N case
Streaming support for M2 case
Importance of SOAP
• SOAP defines a very obvious message structure
with a header and a body
• The header contains information used by the
“Internet operating system”
– Destination, Source, Routing, Context, Sequence
Number …
• The message body is only used by the application
and will never be looked at by “operating system”
except to encrypt, compress it etc.
• Much discussion in field revolves around what is in
header!
– e.g. WSRF adds a lot to header
Web Services
• Java is very powerful partly due to its many “frameworks” that
generalize libraries e.g.
– Java Media Framework
– Java Database Connectivity JDBC
• Web Services have a correspondingly collections of specifications
that represent critical features of the distributed operating systems
for “Grids of Simple Services”
– Some 60 active WS-* specifications for areas such as
– a.
Core Infrastructure Specifications
– b.
Service Discovery
– c.
Security
– d.
Messaging
– e.
Notification
– f.
Workflow and Coordination
– g.
Characteristics
– h.
Metadata and State
– i.
User Interfaces
A List of Web Services I
• a) Core Service Architecture
• XSD XML Schema (W3C Recommendation) V1.0 February 1998,
V1.1 February 2004
• WSDL 1.1 Web Services Description Language Version 1.1, (W3C
note) March 2001
• WSDL 2.0 Web Services Description Language Version 2.0, (W3C
under development) March 2004
• SOAP 1.1 (W3C Note) V1.1 Note May 2000
• SOAP 1.2 (W3C Recommendation) June 24 2003
• b) Service Discovery
• UDDI (Broadly Supported OASIS Standard) V3 August 2003
• WS-Discovery Web services Dynamic Discovery (Microsoft,
BEA, Intel …) February 2004
• WS-IL Web Services Inspection Language, (IBM, Microsoft)
November 2001
A List of Web Services II
• c) Security
• SAML Security Assertion Markup Language (OASIS) V1.1 May
2004
• XACML eXtensible Access Control Markup Language (OASIS)
V1.0 February 2003
• WS-Security 2004 Web Services Security: SOAP Message
Security (OASIS) Standard March 2004
• WS-SecurityPolicy Web Services Security Policy (IBM,
Microsoft, RSA, Verisign) Draft December 2002
• WS-Trust Web Services Trust Language (BEA, IBM, Microsoft,
RSA, Verisign …) May 2004
• WS-SecureConversation Web Services Secure Conversation
Language (BEA, IBM, Microsoft, RSA, Verisign …) May 2004
• WS-Federation Web Services Federation Language (BEA, IBM,
Microsoft, RSA, Verisign) July 2003
A List of Web Services III
• d) Messaging
• WS-Addressing Web Services Addressing (BEA, IBM, Microsoft)
March 2004
• WS-MessageDelivery Web Services Message Delivery (W3C
Submission by Oracle, Sun ..) April 2004
• WS-Routing Web Services Routing Protocol (Microsoft) October 2001
• WS-RM Web Services Reliable Messaging (BEA, IBM, Microsoft,
Tibco) v0.992 March 2004
• WS-Reliability Web Services Reliable Messaging (OASIS Web Services
Reliable Messaging TC) March 2004
• SOAP MOTM SOAP Message Transmission Optimization Mechanism
(W3C) June 2004
• e) Notification
• WS-Eventing Web Services Eventing (BEA, Microsoft, TIBCO) January
2004
• WS-Notification Framework for Web Services Notification with WSTopics, WS-BaseNotification, and WS-BrokeredNotification (OASIS)
OASIS Web Services Notification TC Set up March 2004
• JMS Java Message Service V1.1 March 2002
A List of Web Services IV
• f) Coordination and Workflow, Transactions and Contextualization
• WS-CAF Web Services Composite Application Framework including WS-CTX,
WS-CF and WS-TXM below (OASIS Web Services Composite Application
Framework TC) July 2003
• WS-CTX Web Services Context (OASIS Web Services Composite Application
Framework TC) V1.0 July 2003
• WS-CF Web Services Coordination Framework (OASIS Web Services Composite
Application Framework TC) V1.0 July 2003
• WS-TXM Web Services Transaction Management (OASIS Web Services
Composite Application Framework TC) V1.0 July 2003
• WS-Coordination Web Services Coordination (BEA, IBM, Microsoft) September
2003
• WS-AtomicTransaction Web Services Atomic Transaction (BEA, IBM, Microsoft)
September 2003
• WS-BusinessActivity Web Services Business Activity Framework (BEA, IBM,
Microsoft) January 2004
• BTP Business Transaction Protocol (OASIS) May 2002 with V1.0.9.1 May 2004
• BPEL Business Process Execution Language for Web Services (OASIS) V1.1 May
2003
• WS-Choreography (W3C) V1.0 Working Draft April 2004
• WSCI (W3C) Web Service Choreography Interface V1.0 (W3C Note from BEA,
Intalio, SAP, Sun, Yahoo)
• WSCL Web Services Conversation Language (W3C Note) HP March 2002
A List of Web Services V
• h) Metadata and State
• RDF Resource Description Framework (W3C) Set of recommendations expanded
from original February 1999 standard
• DAML+OIL combining DAML (Darpa Agent Markup Language) and OIL
(Ontology Inference Layer) (W3C) Note December 2001
• OWL Web Ontology Language (W3C) Recommendation February 2004
• WS-DistributedManagement Web Services Distributed Management Framework
with MUWS and MOWS below (OASIS)
• WSDM-MUWS Web Services Distributed Management: Management Using Web
Services (OASIS) V0.5 Committee Draft April 2004
• WSDM-MOWS Web Services Distributed Management: Management of Web
Services (OASIS) V0.5 Committee Draft April 2004
• WS-MetadataExchange Web Services Metadata Exchange (BEA,IBM,
Microsoft, SAP) March 2004
• WS-RF Web Services Resource Framework including WS-ResourceProperties,
WS-ResourceLifetime, WS-RenewableReferences, WS-ServiceGroup, and
WS-BaseFaults (OASIS) Oasis TC set up April 2004 and V1.1 Framework March
2004
• ASAP Asynchronous Service Access Protocol (OASIS) with V1.0 working draft G
June 2004
• WS-GAF Web Service Grid Application Framework (Arjuna, Newcastle
University) August 2003
A List of Web Services VI
• g) General Service Characteristics
• WS-Policy Web Services Policy Framework (BEA, IBM,
Microsoft, SAP) May 2003
• WS-PolicyAssertions Web Services Policy Assertions
Language (BEA, IBM, Microsoft, SAP) May 2003
• WS-Agreement Web Services Agreement Specification
(GGF under development) May 2004
• i) User Interfaces
• WSRP Web Services for Remote Portlets (OASIS)
OASIS Standard August 2003
• JSR168: JSR-000168 Portlet Specification for Java
binding (Java Community Process) October 2003
WS-I Interoperability
• Critical underpinning of Grids and Web Services is the
gradually growing set of specifications in the Web Service
Interoperability Profiles
• Web Services Interoperability (WS-I) Interoperability
Profile 1.0a." http://www.ws-i.org. gives us XSD,
WSDL1.1, SOAP1.1, UDDI in basic profile and parts of
WS-Security in their first security profile.
• We imagine the “60 Specifications” being checked out and
evolved in the cauldron of the real world and occasionally
best practice identifies a new specification to be added to
WS-I which gradually increases in scope
– Note only 4.5 out of 60 specifications have “made it” in this
definition
Web Services Grids and WS-I+
• WS-I Interoperability doesn’t cover all the capabilities need to
support Grids
• WS-I+ is designed to minimal extension of WS-I to support
“most current” Grids: it adds support for
– Enhanced SOAP Addressing (WS-Addressing)
– Fault tolerant (reliable) messaging
– Workflow as in IBM-Microsoft standard BPEL
• Security and Notification best practice and support will probably
get added soon
– There are Web Service frameworks here but various IBM v Microsoft v
Globus differences to be resolved
• Portlet-based User Interfaces could be added
• UK OMII Open Middleware Infrastructure Institute is adopting
this approach to support UK e-Science program
– Currently UK e-Science largely either uses GT2 (as in EDG) or Simple
Web Services for “database Grids”
– http://www.omii.ac.uk/
Application Specific Grids
Generally Useful Services and Grids
Workflow WSFL/BPEL
Service Management (“Context etc.”)
Service Discovery (UDDI) / Information
Service Internet Transport  Protocol
Service Interfaces WSDL
Base Hosting Environment
Protocol HTTP FTP DNS …
Presentation XDR …
Session SSH …
Transport TCP UDP …
Network IP …
Data Link / Physical
Higher
Level
Services
Service
Context
Service
Internet
Bit level
Internet
(OSI
Stack)
Layered Architecture for Web Services and Grids
How SERVOGrid Fits In
• There is core Web Services – the “operating
system of the world” – controlled by WS-*
• There is workflow – programming the Grid
• There are very general Web Services and Grids
such as
– Database
– Collaboration
– Job Submittal
• There are some relatively general services and
Grids such as
– Visualization
– GIS
• There are application specific services such as
– Virtual California
Layers of Onion
Application
(level 1 Programming)
Application Semantics (Metadata, Ontology)
Level 2 “Programming”
Systems Metadata (Context, State)
Basic WS-* Infrastructure
Web Service 1
WS 2
WS 3
WS 4
Workflow (level 3) Programming
All SERVOGrid capabilities are built as Web Services with this structure
3 level programming model
Working up from the Bottom





We have the classic (CISCO, Juniper ….) Internet routing the
flood of ordinary packets in OSI stack architecture
Web Services build the “Service Internet” or IOI (Internet on
Internet) with
• Routing via WS-Addressing not IP header
• Fault Tolerance (WS-RM not TCP)
• Security (WS-Security/SecureConversation not IPSec/SSL)
• Information Services (UDDI/WS-Context not
DNS/Configuration files)
• At message/web service level and not packet/IP address level
Software-based Service Internet possible as computers “fast”
Familiar from Peer-to-peer networks and built as a software
overlay network defining Grid (analogy is VPN)
SOAP Header contains all information needed for the “Service
Internet” (Grid Operating System) with SOAP Body containing
information for Grid application service
Consequences of Rule of the Millisecond
• Useful to remember critical time scales
– 1) 0.000001 ms
– CPU does a calculation
– 2) 0.001 to 0.01 ms – MPI latency
– 3) 1 to 10 ms
– wake-up a thread or process
– 4) 10 to 1000 ms – Internet delay
• 4) implies geographically distributed metacomputing can’t in general
compete with parallel systems (OK for some cases)
• 3) << 4) implies RPC not a critical programming abstraction as it ties
distributed entities together and gains a time that is typically only 1%
of inevitable network delay
– However many service interactions are at their heart RPC but
implemented differently at times e.g. asynchronously
• 2) says MPI is not relevant for a distributed environment as low
latency cannot be exploited
• Even more serious than using RMI/RPC, current Object paradigms
also lead to mixed up services with unclear boundaries and autonomy
• Web Services are only interesting model for services today
Linking Modules
Closely coupled Java/Python …
Module
B
Module
A
Method Calls
.001 to 1 millisecond

Coarse Grain Service Model
Service
B
Messages
Service
A
0.1 to 1000 millisecond latency
From method based to RPC to message based to
event-based
“Listener”
Subscribe
to Events
Service B
Publisher
Post Events
Message Queue in the Sky
Service A
What is a Simple Service?
• Take any system – it has multiple functionalities
– We can implement each functionality as an independent distributed
service
– Or we can bundle multiple functionalities in a single service
• Whether functionality is an independent service or one of many
method calls into a “glob of software”, we can always make them as
Web services by converting interface to WSDL
• Simple services are gotten by taking functionalities and making as
small as possible subject to “rule of millisecond”
– Distributed services incur messaging overhead of one (local) to
100’s (far apart) of milliseconds to use message rather than method
call
– Use scripting or compiled integration of functionalities ONLY
when require <1 millisecond interaction latency
• Apache web site has many projects that are multiple functionalities
presented as (Java) globs and NOT (Java) Simple Services
– Makes it hard to integrate sharing common security, user profile,
file access .. services
•
•
•
•
•
Grids of Grids of Simple Services
Link via methods  messages  streams
Services and Grids are linked by messages
Internally to service, functionalities are linked by methods
A simple service is the smallest Grid
We are familiar with method-linked hierarchy
Lines of Code  Methods  Objects  Programs  Packages
Methods
CPUs
Services
Clusters
Component Grids
Compute
Resource Grids
MPPs
Databases
Sensor
Federated
Databases
Sensor Nets
Data
Resource Grids
Overlay
and Compose
Grids of Grids
Component Grids?
• So we build collections of Web Services which we
package as component Grids
–
–
–
–
–
–
–
Visualization Grid
Sensor Grid
Utility Computing Grid
Person (Community) Grid
Earthquake Simulation Grid
Control Room Grid
Crisis Management Grid
• We build bigger Grids by composing component
Grids using the Service Internet
Flood CIGrid
…
Electricity
CIGrid
…
Gas Services
and Filters
Flood Services
and Filters
Collaboration Grid
Sensor Grid
Registry
Gas CIGrid
Portals
GIS Grid
Data Access/Storage
Visualization Grid
Compute Grid
Metadata
Core Grid Services
Security
Notification
Workflow
Messaging
Physical Network
Critical Infrastructure (CI) Grids built as Grids of Grids
Repositories
Federated Databases
Database
Sensors
Streaming
Data
Field Trip Data
Database
Sensor Grid
Database Grid
Research
SERVOGrid
Education
Compute Grid
Data
Filter
Services Research
Simulations
?
GIS
Discovery Grid
Services
Analysis and
Visualization
Portal
Geoscience Research and Education Grids
Customization
Services
From
Research
to Education
Education
Grid
Computer
Farm
IOI and CIE
• Let us study the two layers IOI (Service Internet On the Bit Internet)
and CIE (Context and Information Environment)
• IOI is most “straightforward” as it is providing reasonably well
understood capabilities at a new “level”
• CIE is roughly the inter-service “shared memory” used to manage and
control them at “distributed operating system level
– Critical is “shared” (a database service) versus message based CIE
Application Specific Grids
Generally Useful Services and Grids
Workflow WSFL/BPEL
Service Management (“Context etc.”)
Service Discovery (UDDI) / Information
Service Internet Transport  Protocol
Service Interfaces WSDL
Higher
Level
Services
CIE
IOI
NaradaBrokering
Audio/Video
Conferencing Client
Computer
Modem
Minicomputer
Server
Web Service B
Peers
NaradaBrokering Broker
Network
Firewall
Queues
Stream
Server-enhanced
Messaging
Workstation
Laptop computer
Peers
PDA
Audio/Video
Conferencing Client
NB supports messages
and streams
NaradaBrokering and IOI
• “Software Overlay Network” features
• Support for Multiple Transport protocols
• Support for multiple delivery mechanisms
– Reliable Delivery
– Exactly-once Delivery
– Ordered Delivery
– Optional Delivery optimization modules for different modes
• Compression/Decompression of payloads with optional module
• Coalescing/Fragmentation of payloads with optional module
• NTP Time Service
• Security Service
• Performance Monitoring
• Performance optimized routing with optional module
• Support for WS-Reliability, WS-ReliableMessaging and their
Federation
Virtualizing Communication



Communication specified in terms of user goal and Quality of
Service – not in choice of port number and protocol
Bit Internet Protocols have become overloaded e.g. MUST use
UDP for A/V latency requirements but CAN’t use UDP as
firewall will not support ………
A given “Service Internet” communication can involve multiple
transport protocols and multiple destinations – the latter
possibly determined dynamically
NB Brokers
A
Satellite
UDP
Firewall
HTTP
Software Multicast
NB Broker
Client Filtering
Fast
Link
B1
Hand-Held
Protocol
Dial-up
Filter
B2
B3
Performance Monitoring


Every broker incorporates a Monitoring service that
monitors links originating from the node.
Every link measures and exposes a set of metrics
• Average delays, jitters, loss rates, throughput.



Individual links can disable measurements for
individual or the entire set of metrics.
Measurement
Broker
Broker
Monitoring
intervals can
Node
Node
Service
also be varied
Link
Link
Monitoring Service,
Data
Data
returns measured
Aggregates info
metrics to
Control Message
from nodes in a
Exchange
Performance
certain domain
Aggregator.
Performance Aggregation
Service
NaradaBrokering Service Integration
Proxy Messaging
Handler Messaging
S1
P1
P2
S1
S2
S2
Notification
S1
S?
Service
NB Transport
S2
P?
Proxy
Any Transport
Standard SOAP Transport
Internal to Service: SOAP Handlers/Extensions/Plug-ins Java (JAXRPC) .NET Indigo and special cases: PDA's gSOAP, Axis C++
Fast Web Service Communication I
• IOI Application level Internet allows one to optimize
message streams at the cost of “startup time”, Web Services
can deliver the fastest possible interconnections with or
without reliable messaging
• Typical results from Grossman (UIC) comparing Slow
SOAP over TCP with binary and UDP transport (latter gains
a factor of 1000)
Record
Count
SOAP/XML
Pure SOAP
WS-DMX/ASCII
SOAP
over UDP
WS-DMX/Binary
Binary
over UDP
MB
µ
σ/µ
MB
µ
σ/µ
MB
µ
σ/µ
10000
50000
150000
375000
1000000
5000000
0.93
4.65
13.9
34.9
93
465
2.04
8.21
26.4
75.4
278
7020
7020
6.45%
1.57%
0.30%
0.25%
0.11%
2.23%
0.5
2.4
7.2
18
48
242
1.47
1.79
2.09
3.08
3.88
8.45
0.61%
0.50%
0.62%
0.29%
1.73%
6.92%
0.28
1.4
4.2
10.5
28
140
1.45
1.63
1.94
2.11
3.32
5.60
5.60
0.38%
0.27%
0.85%
1.11%
0.25%
8.12%
Fast Web Service Communication II
• Mechanism only works for streams – sets of related
messages
• SOAP header in streams is constant except for
sequence number (Message ID), time-stamp ..
• One needs two types of new Web Service
Specification
• “WS-StreamNegotiation” to define how one can use
WS-Policy to send messages at start of a stream to
define the methodology for treating remaining
messages in stream
• “WS-FlexibleRepresentation” to define new
encodings of messages
Fast Web Service Communication III
• Then use “WS-StreamNegotiation” to negotiate stream in
Tortoise SOAP – ASCII XML over HTTP and TCP –
– Deposit basic SOAP header through connection – it is part of
context for stream (linking of 2 services)
– Agree on firewall penetration, reliability mechanism, binary
representation and fast transport protocol
– Naturally transport UDP plus WS-RM
• Use “WS-FlexibleRepresentation” to define encoding of a Fast
transport (On a different port) with messages just having
“FlexibleRepresentationContextToken”, Sequence Number,
Time stamp if needed
– RTP packets have essentially this structure
– Could add stream termination status
• Can monitor and control with original negotiation stream
• Can generate different streams optimized for different end-points
CIE: Common Service Information and Metadata
• Consider a collection of services working together
– Workflow tells you how to specify service interaction but more
basically there is shared information or context
specifying/controlling collection
• WS-RF and WS-GAF have different approaches to contextualization –
supplying a common “context” which at its simplest is a token to
represent state
• More generally core shared information includes dynamic service
metadata and the equivalent of configuration information.
• One can supports such a common context either as pool of messages
or as message-based access to a “database” (Context Service)
• Two services linked by a stream are perhaps simplest example of a
collection of services needing context
• Note that there is a tension between storing metadata in messages and
services.
– This is shared versus distributed memory debate in parallel
computing
Four Metadata Architectures
System or Federated Registry or Metadata Catalog
Database
Grid or Domain Specific Metadata Catalogs
Database1
Database2
Database3
Web Service Ports
SDE1
SDE2
SDE1
SDE2
SDE1
SDE2
SDE1
SDE2
SDE1
SDE2
SDE1
SDE2
SDE1
SDE2
Service
Service
Service
Service
Service
Service
Service
Individual Services
M
M
M
M
M
M
M
Messages
M
M
M
M
M
Notification Architecture
• Point-to-Point
Service B
Publish
Subscribe
Service A
• Or Brokered
Subscribe
Service B
Broker
Queues Messages
Supports creation
and subscription of topics
Publish
Service A
• NaradaBrokering will support both WS-Eventing
and WS-Notification as well as Java Message
Service JMS that is Java Notification standard
Architecture Characteristics
• Build as Component Web Services Grids
–
–
–
–
Simulation
Visualization
GIS
Database
• NaradaBrokering provides
–
–
–
–
Fault Tolerance
Support for High Performance Streams
Basic Dynamic Information Environment
Notification
• HPSearch provides
– More flexible information environment with scripting
– Can prototype simple workflow before implementing in BPEL
• Scripted Information Environment plus Workflow supports
Complexity (multi-scale iterations)