1. WOSS 2002Selvin George1 A Biologically Inspired Programming Model for Self-Healing Systems Selvin George Computer Science David Evans Computer Science Lance Davidson Biology U N I V E R S I T Y O F V I R G I N I A

2. WOSS 2002Selvin George2 Self Healing in Nature

3. WOSS 2002Selvin George3 Diffusion – Local Communication Cells are aware of surroundings by sensing chemicals emitted by other cells

4. WOSS 2002Selvin George4 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)

5. WOSS 2002Selvin George5 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

6. WOSS 2002Selvin George6 state s1 { emits (a, 0.1) transitions (0 (s2, s2) axis; -> (s1); } state s2 { emits (a, 0.1) transitions (0 (s3, s3) normal-X; -> (s2); } state s3 { emits (a, 0.1) transitions (0 (s1, s1) normal-Y; -> (s3); } Blastula Program s1 s2 s3 a a a

7. WOSS 2002Selvin George7 Self-Healing Blastula 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); } Kill Cell

8. WOSS 2002Selvin George8

9. WOSS 2002Selvin George9 Distributed Wireless File Service File Distribution and Update Server replicate inhibit

10. WOSS 2002Selvin George10 Distributed Wireless File Service File Distribution and Update

11. WOSS 2002Selvin George11 Purple Nodes – store File 1 Concentric Circles – Inhibit/Replicate Green Circle – File Request White Circle – Server Response DWFS Simulation

12. WOSS 2002Selvin George12 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