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# Accession Number:

## ADP002913

# Title:

## Optimal File Allocation Problems for Distributed Data Bases in Unreliable Computer Networks II,

# Descriptive Note:

# Corporate Author:

## MASSACHUSETTS INST OF TECH CAMBRIDGE LAB FOR INFORMATION AND DECISION SYSTEMS

# Report Date:

## 1983-12-01

# Pagination or Media Count:

##
13.0

# Abstract:

## The problem investigated consists of determining the optimal locations of files and the number of redundant copies of these files, in a vulnerable command, control and communications network. It is assumed that each node and link of the communications network can fail independently of the others. The optimization problem maximizes the probability that a commander is able to access the subset of the files that he needs while minimizing the network-wide costs. These network-wide costs are storage costs and costs due to the time delay in query and update requests of the distributed data base system. The problem can be shown to reduce to a zero-one liner programming problem. The authors look for theorems which reduce the complexity of the solution of the zero-one linear programs. Finally a heuristic algorithm has been developed to solve the zero-one linear program. An efficient polynomial time algorithm has been developed for the totally reliable network case. They try to extend the efficient polynomial time algorithm to the unreliable network case. Author

# Distribution Statement:

## APPROVED FOR PUBLIC RELEASE

#