Development of a Distributed Task Bag Using CORBA

1
Development of a Distributed Task Bag Using CORBA

• Frank McCown
• Operating Systems UALR
• Dec. 6, 2001

2
Task Bag

• Concept originated from Linda system at Yale as
  distributed memory.
• Master/Slave paradigm

3
Task Bag Operations

• pairOut(key, value) Adds the Pair (key/value)
  to the Task Bag. If a Pair already exists with
  the same key, that Pair is replaced with the new
  Pair.
• pairIn(key) ? value Causes some Pair in the
  Task Bag that matches key to be withdrawn from
  the Task Bag. The value part of the Pair is
  returned. If no matching Pair is available, an
  empty value is returned to the caller.
• readPair(key) ? value Same as pairIn except the
  Pair is not removed from the Task Bag.

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Tasks for Task Bag

• Any problem that can be divided into sub-tasks
  and solved in parallel
• Searching for text in multiple files
• Finding set of prime numbers
• Computing fractal images
• Performing matrix multiplication

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Matrix Multiplication
X

A
B
Result

• Each ResultR,C is computed using row R from A
  and column C from B.

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Implementation

• Task Bag is distributed object
• 2 choices for implementing distributed system
• Java RMI
• CORBA - ORBacus
• Programming language Java
• Platform Any

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Task Bag Pairs

• Data Pairs Matrix rows and columns for use by
  Workers
• Task Pairs Row and Column to be calculated for
  Workers
• Result Pairs Result of calculation for Row and
  Column for Master

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Event Notification

• Master must be notified when results are
  available.
• Workers must be notified when work is available.

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Order of Events
10
IDL
interface TaskBag oneway void pairOut(in
string key, in string value) oneway void
pairOutTask(in string key, in string value)
oneway void pairOutResult(in string key, in
string value, in string workerName) string
pairIn(in string key) string pairInTask(in
string key, in string workerName) string
readPair(in string key)
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Demo

• Start Naming Service. start java
  com.ooc.CosNaming.Server ORBconfig project.conf
• Start Master. java TaskMaster
• Start Workers. java Worker
• Place tasks in Task Bag for Workers to do.