Folie 1

1
Architecture Concept for a Distributed Database
and Data Management System for Disadvantaged
Communication Networks MCC 2008,
23.09.2007 Thomas Nitsche On behalf of Norman
Jansen and Marc Spielmann FGAN/FKIE
2
Outline

• Introduction Challenges of Tactical
  Communication Networks
• Object-Oriented Data Model
• Local Object Bases
• Replication
• Data Management and Configuration Rules
• Implementation
• Conclusion

3
1) Introduction Network Enabled Capabilities

• Provide a global information grid (GIG)
  connecting all participating elements

Sensors
Actors
GIG
Command Control

• Aim
• Provide relevant data in timely manner ? CROP
• Requires Full integration of tactical level

4
Restrictions of the Tactical Level

• Low bandwidth, Fragmented networks
• Limited capabilities of mobile devices

5
Restrictions of the Tactical Level

• Low bandwidth, Fragmented networks
• Limited capabilities of mobile devices

DB
DB
DB
DB
DB
DB

• ? Redundancies are necessary to provide
  continuous, system-wide availability of functions
  and information
• Store data locally at different network nodes
• Minimize data exchanged ? provide relevant data
  on demand

6
Object-Oriented Data Model
Represent military units as objects
7
Object-Oriented Data Model (2)

• Objects represent military units, positions,
  etc.
• Unique object identifier (OID)
• Some attributes

position
absPt59
BN
8
Object-Oriented Data Model (2)

• Objects represent military units, positions,
  etc.
• Unique object identifier (OID)
• Some attributes
• Object graph set of objects connected by links

position
absPt61
BN_CmdPost
unit
commandPost
position
absPt59
BN
9
Object-Oriented Data Model (2)

• Objects represent military units, positions,
  etc.
• Unique object identifier (OID)
• Some attributes
• Object graph set of objects connected by links
• Pathes used to navigate
• E.g. commandPost.position ? absPt61

position
absPt61
BN_CmdPost
unit
commandPost
position
absPt59
BN
10
Object-Oriented Data Model (2)

• Objects represent military units, positions,
  etc.
• Unique object identifier (OID)
• Some attributes
• Object graph set of objects connected by links
• Pathes used to navigate
• E.g. commandPost.position ? absPt61
• Data category mnemonic identifier for OID
• E.g. BlueForce ? BN

11
Object-Oriented Data Model (2)

• Objects represent military units, positions,
  etc.
• Unique object identifier (OID)
• Some attributes
• Object graph set of objects connected by links
• Pathes used to navigate
• E.g. commandPost.position ? absPt61
• Data category mnemonic identifier for OID
• E.g. BlueForce ? BN

position
absPt61
BN_CmdPost
unit
commandPost
position
BlueForce
absPt59
BN

• Object modifications only allowed by owner ?
  cloning

12
Local Object Bases

• Local Object Bases (LOB)
• Private database for each user (unit,
  organisation, role, )
• Holds data objects (currently) relevant for user
• LOBS are logical entities ? can be shared by one
  physical DB
• Assumption Applications and LOB of each user
  reside one same network node

Data replication
13
Initialization of Local Object Bases

• Initialization phase
• Special component (initializer) controls
  initialization of LOBs
• Transfer initial data (and configuration rules)
  to LOBs
• Until LOBs have well-defined initial state
• Deployment phase
• Data is replicated among (regular) LOBs

Communication
Local DB access
Replication (Disadvantaged communication)
Initialization (Broadband, stable)
14
Replication Update

• Update mechanism
• Employs primary copy method
• Each object is owned by some LOB (? primary copy)
• If owner modifies object changes are propagated
  asynchronously

BN
Coy2
(1) Write (modify own position)
(2) Update (propagate changed attribute)
15
Replication Update (2)

• Update mechanism
• Employs primary copy method
• Each object is owned by some LOB (? primary copy)
• If owner modifies object changes are propagated
  asynchronously
• Advantages
• Large bandwidth reduction read and write are
  local operations
• No inconsistencies due to concurrent
  modifications possible
• Disadvantages
• Objects (local copies) can temporarily be
  out-dated
• Modification only allowed for own objects ?
  cloning necessary
• ? Suited for disadvantaged networks

16
Replication Subscribe/Download

• Subscribe to arbitrary data of a unit
  (publisher)
• Further bandwidth reduction
• Subscription data category filter (?
  fine-grained subset of LOB)
• Download (pull) updates (current state) only on
  subscribers request (? allows prioritization)

17
Data Management

• Replication mechanism
• Provides flexible technical basis for replicating
  data objects
• TODO Specify relevant data (What data is to be
  replicated and when?)
• Data management
• For initialization
• For controlling the replication between LOBs
• Allows administrator to easily
• Specify the information needs of units
• Configure the system
• Adapt to changing situations in network centric
  operations
• ? Configuration rules

18
Configuration Rules

• Configuration rules
• Describe relevant information according to
  certain operational situation
• First approach
• Which data objects are to be replicated from
  which LOBs
• How data is manipulated (e.g., aggregated)
• How objects are integrated into own LOB
• Two sets per LOB Configuration rules for
• Initialization phase
• Initializer sends config. rules to each LOB
• Each LOB configures its replication according
  these rules
• Each LOB reads initial data according to config.
  rules
• Deployment phase
• Exchange data objects according to config. rules

19
Configuration Rules (2) Subscription

• Subscription rules describe which data is to be
  replicated
• DestCategory SUBSCRIBE( Publisher, Category,
  Filter)
• Example
• BlueForceChild SUBSCRIBE( LOB(BN), BlueForce, e
  position)

LOB(Co)
LOB(BN)
position
position
BlueForce
BlueForce
BN
absPt61
Co
absPt62
commandPost
unit
commandPost
unit
position
BN_CmdPost
absPt59
20
Configuration Rules (2) Subscription

• Subscription rules describe which data is to be
  replicated
• DestCategory SUBSCRIBE( Publisher, Category,
  Filter)
• Example
• BlueForceChild SUBSCRIBE( LOB(BN), BlueForce, e
  position)

LOB(Co)
LOB(BN)
position
position
BlueForce
BlueForce
BN
absPt61
Co
absPt62
commandPost
unit
commandPost
unit
position
BN_CmdPost
absPt59
21
Configuration Rules (2) Subscription

• Subscription rules describe which data is to be
  replicated
• DestCategory SUBSCRIBE( Publisher, Category,
  Filter)
• Example
• BlueForceChild SUBSCRIBE( LOB(BN), BlueForce, e
  position)

LOB(Co)
LOB(BN)
position
position
BlueForce
BlueForce
BN
absPt61
Co
absPt62
commandPost
unit
commandPost
unit
position
BN_CmdPost
absPt59
22
Configuration Rules (2) Subscription

• Subscription rules describe which data is to be
  replicated
• DestCategory SUBSCRIBE( Publisher, Category,
  Filter)
• Example
• BlueForceChild SUBSCRIBE( LOB(BN), BlueForce, e
  position)

LOB(Co)
LOB(BN)
position
position
BlueForce
BlueForce
BN
absPt61
Co
absPt62
commandPost
unit
commandPost
unit
position
BN_CmdPost
absPt59
23
Configuration Rules (2) Subscription

• Subscription rules describe which data is to be
  replicated
• DestCategory SUBSCRIBE( Publisher, Category,
  Filter)
• Example
• BlueForceChild SUBSCRIBE( LOB(BN), BlueForce, e
  position)

LOB(Co)
LOB(BN)
position
BlueForce
BlueForce
BN
absPt61
commandPost
unit
commandPost
unit
position
BN_CmdPost
absPt59
24
Configuration Rules (2) Subscription

• Subscription rules describe which data is to be
  replicated
• DestCategory SUBSCRIBE( Publisher, Category,
  Filter)
• Example
• BlueForceChild SUBSCRIBE( LOB(BN), BlueForce, e
  position)

LOB(Co)
LOB(BN)
position
BlueForce
BlueForce
BN
absPt61
commandPost
unit
commandPost
unit
position
BN_CmdPost
absPt59
position
Co
absPt62
25
Configuration Rules (2) Subscription

• Subscription rules describe which data is to be
  replicated
• DestCategory SUBSCRIBE( Publisher, Category,
  Filter)
• Example
• BlueForceChild SUBSCRIBE( LOB(BN), BlueForce, e
  position)

LOB(Co)
LOB(BN)
position
BlueForce
BlueForce
BN
absPt61
commandPost
unit
commandPost
unit
position
BN_CmdPost
absPt59
BlueForce Child
position
Co
absPt62
26
Configuration Rules (3) Modification

• Modification rules describe how data should be
  modified
• MODIFY( Trigger, Operation, DestCategory)
• Example
• MODIFY( BlueForceChild0, BlueForceChild1,
• geometricMean,
• BlueForce)

LOB(BN)
Objects
Operations
geometricMean
BN_CmdPost
absPt61
BlueForce
BN
absPt59
BlueForce Child1
BlueForce Child0
Co1
absPt71
absPt73
Co2
Co1_CmdPost
absPt72
Co2_CmdPost
absPt74
27
Configuration Rules (3) Modification

• Modification rules describe how data should be
  modified
• MODIFY( Trigger, Operation, DestCategory)
• Example
• MODIFY( BlueForceChild0, BlueForceChild1,
• geometricMean,
• BlueForce)

LOB(BN)
Objects
Operations
geometricMean
BN_CmdPost
absPt61
BlueForce
BN
absPt59
BlueForce Child1
BlueForce Child0
Co1
absPt71
absPt73
Co2
(1) update of a position by replication
Co1_CmdPost
absPt72
Co2_CmdPost
absPt74
28
Configuration Rules (3) Modification

• Modification rules describe how data should be
  modified
• MODIFY( Trigger, Operation, DestCategory)
• Example
• MODIFY( BlueForceChild0, BlueForceChild1,
• geometricMean,
• BlueForce)

LOB(BN)
Objects
Operations
geometricMean
BN_CmdPost
absPt61
BlueForce
BN
absPt59
(2) read
BlueForce Child1
BlueForce Child0
Co1
absPt71
absPt73
Co2
Co1_CmdPost
absPt72
Co2_CmdPost
absPt74
29
Configuration Rules (3) Modification

• Modification rules describe how data should be
  modified
• MODIFY( Trigger, Operation, DestCategory)
• Example
• MODIFY( BlueForceChild0, BlueForceChild1,
• geometricMean,
• BlueForce)

LOB(BN)
Objects
Operations
geometricMean
BN_CmdPost
absPt61
(3) read
BlueForce
BN
absPt59
BlueForce Child1
BlueForce Child0
Co1
absPt71
absPt73
Co2
Co1_CmdPost
absPt72
Co2_CmdPost
absPt74
30
Configuration Rules (3) Modification

• Modification rules describe how data should be
  modified
• MODIFY( Trigger, Operation, DestCategory)
• Example
• MODIFY( BlueForceChild0, BlueForceChild1,
• geometricMean,
• BlueForce)

LOB(BN)
Objects
Operations
(4) modify
geometricMean
BN_CmdPost
absPt61
BlueForce
BN
absPt59
BlueForce Child1
BlueForce Child0
Co1
absPt71
absPt73
Co2
Co1_CmdPost
absPt72
Co2_CmdPost
absPt74
31
Implementation

• Experimental service-oriented network-based C2IS
  (PLATO)
• PLATO system contains general framework for
  building services

• Based on service framework implemented
  distributed CROP management service and
  initializer
• First set of configuration rules in XML

32
Conclusion

• Introduced concept of local object bases (LOBs)
• Model for OO distributed DB system
• Data objects are stored partially redundant in
  LOBs
• Each LOB manages data relevant for one user
• Replication mechanism (subscribe/download-method)
• Adapted to requirements of tactical networks
• Specify precisely which data objects to replicate
• Reduces communication costs
• Data Management mechanisms
• Configuration rules for LOBs
• Control initialization and replication during
  runtime
• Future work
• Develop formal language for config. rules
• Simple enough for admin vs. sufficiently
  expressive

33
Conclusion

• Introduced concept of local object bases (LOBs)
• Model for OO distributed DB system
• Data objects are stored partially redundant in
  LOBs
• Each LOB manages data relevant for one user
• Replication mechanism (subscribe/download-method)
• Adapted to requirements of tactical networks
• Specify precisely which data objects to replicate
• Reduces communication costs
• Data Management mechanisms
• Configuration rules for LOBs
• Control initialization and replication during
  runtime
• Future work
• Develop formal language for config. rules
• Simple enough for admin vs. sufficiently
  expressive

Questions? jansen, spielmann_at_fgan.de