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4 SFC / CSO [email protected] — 4 — 2017-02-24 – p.1/34

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FLP CAP CUP ( ) P2P — 4 — 2017-02-24 – p.2/34

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1. 2. 3. P2P 4. — 4 — 2017-02-24 – p.3/34

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1. FLP CAP — 4 — 2017-02-24 – p.4/34

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A, B A-B m A B A B A B . . . — 4 — 2017-02-24 – p.5/34

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1. X 2. X C 3. C 1. 2. 3. reliable multicast — 4 — 2017-02-24 – p.6/34

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: — 4 — 2017-02-24 – p.7/34

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(safety) (liveness) ( ) ( = ) — 4 — 2017-02-24 – p.8/34

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→ / (benign) → (Byzantine) (malicious) — 4 — 2017-02-24 – p.9/34

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FLP Fischer, Lynch, Paterson — 4 — 2017-02-24 – p.10/34

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CAP Consistency ( ) Availability ( ) Partition tolerance ( ) ⇒ 3 C Eventual consistency ( ) . . . — 4 — 2017-02-24 – p.11/34

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Consistency ( ) Strong consistency ( ) (safety) Eventual consistency ( ) (liveness) ↑ Weak consistency ( ) ↑ ( ) — 4 — 2017-02-24 – p.12/34

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n = f ( ) — 4 — 2017-02-24 – p.13/34

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(1) 1 1, 2 n ≤ 3f — 4 — 2017-02-24 – p.14/34

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(2) — 4 — 2017-02-24 – p.15/34

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CS1 : CS2 : CS3 : CL1 : CL2 : : : (e.g. ) — 4 — 2017-02-24 – p.16/34

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Paxos (1) : (The Part-Time Parliament) Paxos ( ) ↔ ↔ ↔ ⇒ — 4 — 2017-02-24 – p.17/34

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Paxos (2) (proposers), (acceptors), (learners) 1. 2. Paxos ( ) — 4 — 2017-02-24 – p.18/34

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Paxos Paxos 2f + 1 Paxos f “byzantizing” Byzantine Paxos PBFT (Practical Byzantine Fault-Tolerance) PBFT — 4 — 2017-02-24 – p.19/34

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2. CUP (Consensus with Unknown Participants) - — 4 — 2017-02-24 – p.20/34

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(B)FT-CUP (Consensus with Unknown Participants) ( / ) : FT (Fault-Tolerant) : BFT (Byzantine Fault-Tolerant) P2P n FT/BFT — 4 — 2017-02-24 – p.21/34

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- n ( ) p.6 — 4 — 2017-02-24 – p.22/34

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3. P2P P2P - - — 4 — 2017-02-24 – p.23/34

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P2P : P2P 3 3 ( ) strategyproof group strategyproof — 4 — 2017-02-24 – p.24/34

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(Sybil) 16 — 4 — 2017-02-24 – p.25/34

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again n > 3f R F R > 2F ⇒ — 4 — 2017-02-24 – p.26/34

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( ) f = 1 ⇒ R — 4 — 2017-02-24 – p.27/34

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4. — 4 — 2017-02-24 – p.28/34

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3 1. ( ) ⇒ 2. ( ) ⇒ 3. ( ) TX · ⇒ — 4 — 2017-02-24 – p.29/34

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10 ATM 1 ATM 1 : http://www.slideshare.net/yamaz2/ss-58813038 ⇒ KVS — 4 — 2017-02-24 – p.30/34

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— 4 — 2017-02-24 – p.31/34

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vs. — 4 — 2017-02-24 – p.32/34

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(centralized) (decentralized) (distributed) Paul Baran, “On Distributed Communications Networks”, 1964 (C) (A) — 4 — 2017-02-24 – p.33/34

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— 4 — 2017-02-24 – p.34/34