woss 2002selvin george1 a biologically inspired programming model for self-healing systems selvin...

WOSS 2002 Selvin George 1

A Biologically Inspired Programming Model

for Self-Healing Systems

Selvin GeorgeComputer Science

David EvansComputer Science

Lance DavidsonBiology

U N I V E R S I T Y O F V I R G I N I A

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Self Healing in Nature

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Diffusion – Local Communication

Cells are aware of surroundings by sensing chemicals emitted by other cells

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Nature’s Programs – Observations

• Aware• Of self• Of environment

• Redundant• Decentralized• Expressive

• Human program – 3 billion base pairs (~250MB)

• Two human programs differ by about 0.5MB (< 1% of Windows 2000)

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Our Programming Model

• Similar to cellular automata• Simple chemical diffusion model• Correspondence to biological cells

– Genes turn on and off state changes•Emit different chemicals depending on

state•Change state based on sensed chemicals

– Cells can divide asymmetrically

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state s1 { emits (a, 0.1) transitions (0 <= a <= 0.375) -> (s2, s2) axis; -> (s1);}

state s2 { emits (a, 0.1) transitions (0 <= a <= 0.375) -> (s3, s3) normal-X; -> (s2);}

state s3 { emits (a, 0.1) transitions (0 <= a <= 0.375) -> (s1, s1) normal-Y; -> (s3);}

Blastula Progra

ms1

s2

s3

a

a

a

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Self-Healing Blastulastate s1 { emits (a, 0.1) transitions (0 <= a <= 0.375) -> (s2, s2) axis; -> (s1);}

state s2 { emits (a, 0.1) transitions (0 <= a <= 0.375) -> (s3, s3) normal-X; -> (s2);}

state s3 { emits (a, 0.1) transitions (0 <= a <= 0.375) -> (s1, s1) normal-Y; -> (s3);}

Kill Cell

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Distributed Wireless File Service

File Distribution and Update

Server

replicate

inhibit

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Distributed Wireless File Service

File Distribution and Update

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Purple Nodes – store File 1

Concentric Circles– Inhibit/Replicate

Green Circle– File Request

White Circle– Server Response

DWFSSimulatio

n

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Mantra

• Biology has killed trillions of organisms over millions of years to solve complex engineering problems

• Engineers should be able to learn from these solutions

• Simulator available: http://swarm.cs.virginia.edu/cellsim