8/2/2019 (3)BASE - Using Abstraction to Improve Fault Tolerance

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BASE: Using Abstraction to Improve Fault Tolerance

Rodrigo Rodrigues , Miguel Castro , and Barbara Liskov MIT Laboratory for Computer Science

200 Technology Sq., Cambridge MA 02139, USA Microsoft Research Ltd.

1 Guildhall St., Cambridge CB2 3NH, UK

rodrigo@lcs.mit.edu, mcastro@microsoft.com, liskov@lcs.mit.edu

ABSTRACT

1. INTRODUCTION

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2. THE BASE TECHNIQUE

2.1 Methodology

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2.1.1 Applicability

2.2 The BASE Library

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execute

propose_value/check_value

get_obj/put_objshutdown/restart

Client

BASE

Client

BASE

Replica

Conf.

Wrapper

Original

Implementation

invoke

BASEProtocol

modify

3. EXAMPLES

3.1 File System

3.1.1 Abstract Specification

Andrewbenchmark

kernel NFS client

relay

replicationlibrary

replica 1

unmodified NFS daemon 1

replicationlibrary

conformancewrapper

stateconversion

unmodified NFS daemon n

replicationlibrary

conformancewrapper

stateconversion

replica n

client

3.1.2 Conformance Wrapper

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3.1.3 State Conversions

TypeGen. #Parent

Attrs

Data

0

FILE12

DIR10

FILE10

DIR1-1

t1

other attrs

FREE0

1 2 3 4

TypeGen. #Parentfhandletstamps

DIR1-1

h1t1

FILE10

h2t2

DIR10

h3t3

FREE0

0 1 2 3

FILE12

h4t4

root

f1

f2

d1

Abstract State:

Conformance Representation: Concrete State:

4

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-

-

3.1.4 Proactive Recovery

3.2 Object-Oriented Database

3.2.1 System Overview

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-

3.2.2 Abstract Specification

3.2.3 Conformance Wrapper

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3.2.4 State Conversions

4. EVALUATION

4.1 File System Overhead

4.1.1 Experimental Setup

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4.1.2 Homogeneous Results

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4.1.3 Heterogeneous Results

4.2 Object-Oriented Database Overhead

4.2.1 Experimental Setup

4.2.2 OO7 Results

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0

5

10

15

20

T1 T6 T1 T6

Thor BASE-Thor

Elapsedtime(s)

Commit

Traversal

0

5

10

15

20

T2a T2b T2a T2b

Thor BASE-Thor

Elapsedtime(s)

Commit

Traversal

4.3 Code Complexity

5. RELATED WORK

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6. CONCLUSION

7. ACKNOWLEDGMENTS

8. REFERENCES

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