Data Sharing Service

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Data Sharing Service

• Kiran Devaram
• Samatha Gangapuram
• Harish Maringanti
• Prashant Shanti Kumar
• Pradeep Tallogu

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Overview

• CORBA specification
• CCM Specification
• Middleware description
• Demo of Existing System
• Project scenario
• Project scope
• List of assumptions

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CORBA specification

• Common Object Request Broker Architecture
• An architecture and specification for
  creating, distributing, and managing distributed
  program objects in a network

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Object Semantics

• Objects
• Requests
• Object creation and Destruction
• Types
• Interfaces
• Value types
• Abstract Interfaces
• Operations
• Attributes

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ORB request path
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Client Request Path
Client
Object Implementation
Dynamic Invocation
IDL Stubs
ORB Interface
Static IDL skeleton
Dynamic skeleton
Object Adapter
ORB Core
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ORB Structure
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Corba Component Model (CCM)

• CORBA Component Model (CCM) is a
  specification for creating server-side scalable,
  language-neutral, transactional, multi-user and
  secure enterprise-level applications.

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Typical CCM Specification consists

• CCM Containers
• CORBA components that run in these containers
• Portable Object Adapter (POA)
• Object Request Broker (ORB)
• other CORBA object services like CORBA
  Transactions, CORBA Security, CORBA Persistence,
  CORBA Events, etc...

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CCM scenario
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CORBA Component

• Component is a new CORBA meta-type.
• Extension of Object (with constraints)
• Has an interface, and an object reference
• Also, a stylized use of CORBA interfaces/objects
• Provides component features (also named Ports)
• Could inherit from a single Component type
• Could support multiple interfaces
• Each component instance is created and managed by
  a unique component home

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Component Features

• Attributes configurable
• properties
• Facets offered operation
• interfaces
• Receptacles required operation
• interfaces
• Event sources produced events
• Event sinks consumer events

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CORBA Component
Component Interface
Facet
Receptacles
Event sink
Event Sources
Attributes
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Middleware Data Service

• Developed by Rockwell Collins ATC
• Used to simulate data sharing between components
  in an aircraft
• Highlights
• Data sharing
• Rate handling
• Data Staleness handling
• Bounds checking
• Error logging
• Scope for functional increments

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Data Service contd..

• Basic methods
• Advertise
• Subscribe
• getValue
• setValue
• getDataChannel
• sendGroup

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Advertise call path
getDataChannel (name)
Producer
Avionics Data Service
Advertise ()
Data Channel
SetValue
a
b
c
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Producer Consumer connections
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Project Scenario

• Number of Components 3
• Technologies
• OpenCCM 0.4
• OpenORB 1.2.1
• Java
• Services
• Data Service
• Naming Service

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Existing Architecture
Producer
Consumer and Producer
Timer
event
Consumer
event
event
Get Data Set Data
Get Data
Set Data
Data Service
Configuration File
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Existing system demo
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Architecture
Producer
Consumer and Producer
Consumer
Up call
getData setData
Set Data
Up call
Up call
Data Service
Configuration File (Timer Service)
Wrapper
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Project Scope

• Providing up-call capability to Data Service
• Improving data services rate handling mechanism
• Enhance performance by including thread pool for
  making component calls

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Up-Call Management

• Include new wrapper within the Data Service
• Resolve component reference through Name Service
• Receive trigger calls from timer
• Package component call to include role
• Retrieve thread from thread pool
• Make up-call to respective components

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Data Service Rate Handling

• Pull - model
• Store producer proxy reference within consumer
  proxy
• Break set data call at producer proxy
• Look up producer proxy reference at getData call
• Retrieve most recent data from Producer proxy

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Thread Pool Implementation

• Provide thread pool for component calls
• Resource utilization through pre-spawning fixed
  number of threads
• Data Service uses worker thread to make up-call
• Same thread does a set or get on the Data Item
• Thread sync maintained between multiple threads

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Assumptions

• Only one producer for each data item
• Maintaining naming convention for each component
• Scenario architecture is known

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References

• Object Management Group formal
  specification catalogue
• Avionics Data Service documentation
• OpenCCM documentation
• OpenORB manual

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• Comments and Questions

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Go Cats

• Go K-State Beat Nebraska