Adaptable Connectors in the CORBA Component Model

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Adaptable Connectors in theCORBA Component Model

• Mathieu Vadet Philippe Merle
• vadet, merle_at_lifl.fr
• GOAL Team, LIFL

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Objectives

• Adapt event communication layer in distributed
  component oriented applications
• Context CCM
• Platform OpenCCM
• Ease adaptations production and use
• Least-effort programming
• Only communication logic
• Minimize programming faults
• Integration by description
• Configuration and instantiation logic
• Minimize integration faults

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Illustration
Any communication Service
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Issues
OpenCCM adaptable connector
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Issues

• Reification of connector
• MOP sticks to language, CORBA or CCM ?

OpenCCM adaptable connector
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Issues

• Reification of connector
• Many implementations
• CORBA or not CORBA,
• Proprietary information

???
OpenCCM adaptable connector
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Issues

• Reification of connector
• Many implementations
• Instantiation support
• At deployment-time, connection-time, runtime
• Automation means

OpenCCM adaptable connector
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Approach

• Reification of connection operations
• Implemented by framework
• Connector communication logic
• Component oriented connector
• Connector assembly of components
  configuration
• Instantiation deployment

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Illustration
Notification Service
OpenCCM adaptable connector
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Illustration
Notification Service
OpenCCM adaptable connector
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Illustration
Multicast IP
OpenCCM adaptable connector
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Illustration
Multicast IP
OpenCCM adaptable connector
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Illustration
JMS
OpenCCM adaptable connector
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Illustration
OpenCCM adaptable connector
JMS
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Configuration

• Describes used connectors
• Connector initial configuration
• Physical location of the archive
• Entry point
• Proprietary information
• Static deployment
• References on initial configurations
• Dynamic deployment
• Configuration propagation policies
• Looks like simplified CCM deployment descriptors

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Configuration

• Example for Automaton component port

port repository id
static deployment
"IDLAutomaton/to_observer1.0"
connectors staticeventservice
dynamic eventservice
locationhttp//egmont.lifl.fr/eventservice.jar
entrypointEventServiceConnectorHome.creat
e_home addresscorbaloclocalhost8000/
DefaultEventChannel
dynamic deployment
initial configuration
archive physical location
entrypoint
specific
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Configuration

• Example for Observer component port

"IDLObserver/from_automaton1.0"
connectors staticeventservice,multicast
dynamic eventservice /
idem / multicast
locationfile//home/vadet/connectors/multicast.ja
r entrypointMulticastConnectorHome.crea
te_home ip224.0.0.100
port9999
2 connectors deployed statically
2 initial configurations
multicast group infos
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Static Deployment

• First experiment
• Objective
• Deployment-time connections
• Achievement
• Configuration checking algorithm
• Connection validation protocol

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Static Deployment

• Example before deployment
• Same configuration everywhere

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Static Deployment

• Example after deployment
• Same connector instantiated everywhere

Event Service Channel
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Static Deployment

• Example upon connection

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Static Deployment

• Example upon connection
• Manager checks consistency

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Checks consistency OK for that case
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Static Deployment

• Example upon connection
• Manager checks consistency
• Manager validate connection

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3
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Static Deployment

• Example upon connection
• Manager checks consistency
• Manager validate connection
• Connection established

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Static Deployment

• Static adaptation of connectors
• At deployment-time
• Fits well for static connections
• Allows (m,n) connectors
• Drawbacks
• Consistent configurations everywhere
• A priori knowledge of connections
• Complex administration

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Dynamic Deployment

• Next experiment
• Objectives
• Runtime discovery of connector
• Negotiation protocol
• Achievement
• Enhance configuration checking algorithm
• Configuration propagation protocol
• Built-in policies

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Dynamic Deployment

• Example before deployment
• Configuration for automaton
• Specifies propagation of eventservice initial
  configuration

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Dynamic Deployment

• Example before deployment
• Configuration for observers
• Requires the propagation of a configuration

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Dynamic Deployment

• Example after deployment
• Connector is only instanciated for automaton

Event Service Channel
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Dynamic Deployment

• Example upon connection

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Dynamic Deployment

• Example upon connection
• Manager checks consistency

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Checks consistency Needs propagation
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Dynamic Deployment

• Example upon connection
• Manager checks consistency
• Manager sends configuration to the other manager

deploy_profile
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Send configuration with eventservice initial
configuration
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Dynamic Deployment

• Example upon connection
• Manager checks consistency
• Manager send profile to the other manager
• Manager instantiates the connector

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Instanciation of the eventservice connector and
update of the configuration
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Dynamic Deployment

• Example upon connection
• Manager checks consistency
• Manager validate connection

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3
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Dynamic Deployment

• Example upon connection
• Manager checks consistency
• Manager validate connection
• Connection established

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Dynamic Deployment

• Dynamic adaptation of connectors
• At connection-time
• Fits well for dynamic connections
• Ease administration
• Limitations
• Policies too restrictive
• No negotiation
• Drawbacks
• No (m,n) connector

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Lessons Beyond The Experiments

• Connectors seen as distributed assemblies of
  system components
• Design, development, configuration and deployment
• Flexible containers build at runtime
• Parts are downloaded and assembled dynamically
• Distributed coordination between containers
• Configuration propagation
• gt Negotiation
• Could be applied to other component oriented
  middleware
• Ideas are not CCM specific

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Future prospects
Any CS
- No (m,n) connector - No connector spokesman at
runtime
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Future prospects
(m,n) connector Comm. service as CCM component
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Future prospects
Event comm. NF domain

• Any NF domain
• Load balancing
• Fault tolerance
• Real time
• ...