TU Wien:Advanced Internet Computing VU (Dustdar)/MindMap WS09

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Datei:TU Wien-Advanced Internet Computing VU (Dustdar) - MindMap WS09.zip

AIC

  • Open World Assumption
  • EAI
  • SoC
    • Services
      • Standardized Interface / Well-defined - WSDL
      • Self-contained
      • available
      • little integration need
      • granularity
        • fine
        • coarse-grained
      • loosely coupled
      • reusable
      • can be stateful
      • context-independent
      • service-composition
      • QoS
        • measureable
        • availability
        • accessibility
        • integrity
        • performance
      • synchonicity
        • sync RPC-style
        • async message/document-style
    • Interface
      • operations, params, data-typing, access protocols
    • SOA
      • publish/find/bind
      • Roles + grafik
        • Service Providers
        • Service Clients (Requestors)
        • Service Reqistry
      • Technologies
        • Distributed object midware
          • CORBA
          • J2EE
        • Message-oriented midware
          • ActiveMQ
          • IBM WebSphere MQ
        • .. Web services != SOA, = one approach
    • ASP vs Web Services
      • ASP limitations
      • Software as a Service (dazwischen, download)
    • SLAs
      • contract between provider and client
  • Web Services
    • do *
      • Describe
        • WSDL
      • Publish
        • UDDI
      • Find
        • UDDI
      • Bind
        • SOAP
      • Invoke
        • SOAP
      • Compose
        • Orchestration (BPEL)
    • Extended Specifications
      • WS-Addressing
      • WS-Policy
      • WS-MetaDataExchange
      • QoS
        • WS-Security
          • integrate kerberos etc
        • WS-ReliableMessaging
          • in-order delivery, at least/most once
        • WS-Coordination
        • WS-Transaction
          • short/long
      • WS-CDL Choreography Description Language
      • BPEL Business Process Exectution Language
  • SOAP
    • Simple Object Access Protocoll, XML-based messaging protocol
    • Message Format: Header + Body
    • Roles and processing
      • No nodes
      • All nodes except initial sender
      • Only ultimate receiver
      • + additional roles by modules/application
    • Faults
      • Code, Reason
      • optional: detail, node, role
    • Interaction Styles
      • Document literal
        • binding style="document", soap:body use="literal"
      • Remote procedure call
        • binding style="rpc", soap:body use="encoded"
    • Extensibility
      • features (reliability, security, message exchange patterns)
      • Processing model
      • Protocol bindings
    • Message Exchange Patterns (MEP)
      • features extending one-way communication
      • Request-response
    • Bindings
      • how to use transport protocol
      • HTTP intermediaries != SOAP intermediaries
      • Request-response using HTTP POST
      • Response using HTTP GET
    • Attachments
      • XML Base64 encoding
      • SOAP MTOM (abstract), XOP (impl)
      • MIME for binary parts
  • WSDL
    • XML vocabulary to describe Web services
    • exensible and adaptable
    • parts
      • Abstract: operational behaviour (what)
      • Concrete: binding, service (how, where)
    • Abstract
      • Types
        • data type definition (normally XML Schema)
      • Message
        • multiple parts associated with a type
        • RPC -> parts are parameters
      • Operation
        • combinations of input/output
      • Port-type
        • named set of abstract operations
    • WSDL Message Exchange Patterns
      • One-way operation (predefined)
        • async messaging
      • Request-response operation (predefined)
      • Notification operation
        • client has registered for event update
      • Solicit-reponse operation
    • Concrete
      • Bindings
      • Operations
      • Ports
        • individual endpoint, single address
      • Services
        • group of ports, not communicating
        • alternatives for protocol, distance
    • Predefined Bindings
      • SOAP binding
      • HTTP & MIME bindings
    • Problems/Limitations
    • WSDL 2.0
      • simpler, better specified, additional features
      • no message construct
      • interfaces replace port types
      • endpoints replace ports
      • document-style operations first-class-citizens
      • MEPs
        • message exchange patterns more flexible
        • faults as interace sub-elements
        • 8 predefined
          • in-only, out-only
          • robust in-only, robust-out-only
          • in-out, out-in
          • in-optional-out, out-optional-in
      • interface extensions / fault extensions
      • import / include ... different/same target namespace
      • WSDL 1.1 widely used, WSDL 2.0 adoption takes time
  • Web service Composition
    • Business processes
      • activity performed in sequence according to business rules, produces outcome
      • short/long lived
      • internally or between business partners
      • Process model - real world
      • Workflow model - technology interactions
    • Requirements
      • Combine and link existing Web services
      • Flexible, Recursive, Recoverable, Seperation of concerns
    • Issues
      • Abstract process representation
      • Discovery and interoperability
      • Efficiency
      • Process Execution and Monitoring
    • Orchestration vs Choreography
      • Orchestration
        • "part-of" sense
        • compose web services for business processes
        • define composite services
        • reuse of existing web services
      • Choreography
        • "sequencing" sense
        • compose web services for business collaboration
        • peer-to-peer model
        • define how multiple parties collaborate
    • Web services workflows
      • thousands of Web services available
      • requires analysis of web services QoS
    • Composition
      • multi-party conversational interactions
      • approaches
        • process-based
        • requirements-driven
        • AI-based
      • protocols
        • Orchestration (BPEL)
        • Cheoreography (WS-CDL)
        • Event-based federation (WS-Eventing)
      • time
        • design time (static composition)
        • deployment time ... e.g. different services per installation
        • run time (dynamic composition)
      • dynamic issues
        • discovery, QoS parameter negotionation
        • services do not answer, wrong state info, service contract violation
        • service protocols and policies
    • Research
      • Autonomic composition
        • self-configuring
          • discovery
        • self-optimizing
          • selection
        • self-healing
          • reaction
        • self-adapting
          • behaviour-change
      • QoS-aware service compositions
        • respect policies, performance levels,security requirements, SLAs,...
    • WS-BPEL
      • Web Services Business Process Execution Language
      • Process-oriented composition language
      • concrete vs abstract processes
      • mainly orchestration, some choreography support
      • WSDL-based, block-structured
      • Activities - primitive/structured
      • Data handling - containers
      • Processes
        • Abstract
          • may hide optional details
          • describe externally visible interactions
        • Concrete
          • implementation details
          • internal business logic
      • Service Selection
        • Partner Link Type
        • Partner Link
        • Endpoint
      • Binding
        • static/dynamic
      • Adoption/Implementations
        • Apache ODE
        • WebSphere
        • Biztalk erver
        • OraceBPEL
    • WS-CDL
      • Web Services Choreography Description Language
      • Declarative language for B2B interaction patterns
      • Global definition formessage exchanges
        • Ordering conditions
        • Constraints
      • Complementary to WS-BPEL
        • extends choreography support
        • more global view
        • declarative, not executeable
      • hardly adopted, over-engineered and too abstract
  • Transactions
    • Intro
      • QoS-Layer: WS-C, WS-AT, WS-BA
      • Two-phase commit (2PC)
        • prepare, commit
      • Resource locking
      • ACID Properties
      • Atomicity + Consistency + Isolation + Durability
    • WS-Transactions challenges
      • loose coupling
      • distribution
      • heterogeneity
      • long runtimes
    • Long-running activities
      • commit sub-activities on completion
      • error -> rollback, compensation
      • application specific compensation
      • limited isolation, visible intermediary results
    • Coordination / WS-TransactionStandards
      • About
        • example: auction + trading / bidding
        • Protocols
          • message exchange between participant and coordinator
        • Coordinator
          • mediates, agreement protocols
        • Participants
          • must agree on outcome
          • plays one-to-many roles (completer, 2PC resource manager, caching...)
        • Activities
          • combine distributed web services
      • WS-Coordination
        • Foundation layer for coordination
        • Activation, Registration
        • Coordination context
        • Extensibility
      • WS-AtomicTransaction
        • 2-phase commit for web services (2PC)
        • short-lived activities
      • WS-BusinessActivity
        • long-running transactions
        • operation nesting
        • compensation-based
        • combine with atomic transactions
  • WS Metadata UDDI
    • Metadata
      • addressing information for endpoint
      • required extended features
      • QoS attributes
    • Technologies
      • XML Schema
        • data types
      • WSDL
        • messages, interfaces, endpoints
        • message exchange patterns
      • WS-Addressing
        • web service endpoint references
      • WS-Policy
        • QoS requirements
      • UDDI
        • metadata repository
      • WS-MetadataExchange
        • dynamic metadata exchange
    • UBR
      • Universal Business Registry
      • global registry of all services
      • quality issues, availability of services...
      • > mainly private/semi-private UDDIs
    • UDDI
      • Universal Description, Discovery and Integration
      • APIs in WSDL with SOAP binding to publish & query
      • purspose: web service info & dynamic binding
      • Registry
        • White pages: business information
        • Yellow pages: categorization
        • Green pages: technical information
      • Data
        • businessEntity
          • organization
          • contact info
        • businessService
          • web services
          • addresses, versions, protocols, ..
        • bindingTemplate
          • technical manual
          • parameters, default values, ...
        • tModel
          • generic container spec
            • WSDL specification
          • reference to actual document
          • unstrctured, human-readable
      • Dynamic binding
        • standard interface as tModel
        • app queries UDDI for known tModel key
    • WS-Addressing
      • Motivation
        • messaging
          • BPEL
        • coordination/transactions
        • no addressing in SOAP
        • transport-protocol independence required
      • Specifies
        • endpoint references
        • additional SOAP headers
      • Endpoint References
        • map to WSDL port
        • Address URI
        • Reference Property
        • Reference Parameter
        • optional Metadata (port type, policies, ...)
      • Message Headers
        • mandatory: To, Action
        • optional: related endpoints, msg relationships
    • WS-Policy
      • describe nonfunctional service behaviour (vs WSDL)
      • eg: supports/requires transactions, security, QoS
      • WS-Policy (define) + WS-PolicyAttachment (apply)
      • Policy
        • assertions + operators
        • ExactlyOne, All, optional attribute
      • Normal Form for intersection: ExactlyOne + Alls
      • Validation using intersection + domain-specific knowledge
    • WS-MetadataExchange
      • WSDL interface for metadata exchange between endpoints
      • Bootstrapping of interactions
      • Extensibility + Redirection
  • WS-I
    • WS-I Basic Profile
    • subset of proven, interoperable WS features
    • checklist for middleware providers
    • WS-I Basic Security Profile
  • REST
    • Representational State Transfer
    • architectural style for distributed systems
    • basic architecture of the WWW
      • HTTP & URI
    • simple, ad-hoc, light-weight
    • Characteristics
      • Resource-Orientation
        • MIME-type
      • Statelessness
        • so is HTTP
      • Uniform Interface
        • HTTP interface, GET POST PUT HEAD DELETE
      • Naming
        • unique and descriptive
        • URI per resource
      • Layering
        • transparent intermediaries (proxies, caches)
        • supported by HTTP
    • RESTful Web Services
      • in line with the Web
      • HTTP + URI
      • XML or JSON, HTML, ...
      • JAX-RS
        • Java API
        • POJO based
        • annotations
        • Jersey, Apache CXF, JBoss Resteasy
  • SOAP vs REST
    • SOAP & WS-*
      • + protocol transparent
      • + wsdl
      • - fuzzy boundaries
      • performance
    • RESTful
      • + simple & lightweight, HTTP, XML, URI, MIME
      • + HTTP available in languages/platforms
      • + port 80 - firewalls
      • - Hi-REST vs Lo-REST
  • Mashups
    • eg: netvibes
    • ad-hoc
    • client-side / server-side
    • JSON, RSS, Atom
    • Service Mashups
      • combine services with
        • fresh content
        • collaborative approaches (tags)
        • semantic techs (RSS, RDFa, SPARQL)
      • often RESTful
      • Tools
        • Yahoo Pipes
  • Research Questions
    • Autonomic Management