-By Shrutirupa Banerjiee(@freak_crypt) Let Us Gossip About It!! -By Shrutirupa Banerjiee(@freak_crypt)

Who am I? Blockchain and Security Enthusiast Mathematics and Core Cryptography Researcher https://about.me/shrutirupa

What is Gossip??

Key Features Probabilistic Exchange of Information Fault Tolerance Repetitive Reliable Scalable Robust Decentralised

How is the information disseminated???

3 States Susceptible Infected Removed

Susceptible The node does not know about the update

Infected The node knows the update and is actively spreading it

Removed The node knows the update, but it does not participate in the spreading any more

Models SI (Susceptible-Infected) SIR(Susceptible-Infected-Removed)

SI Model push-pull style pull style push style

SIR Model Based on the Push style(Pull could be used as well) Susceptible nodes receiving the update become infected These infected nodes push the update to other nodes The protocol terminates, when all susceptible and infected nodes are switched to removed state.

The decision to transition to the removed state is influenced by the following factors: Blind(evaluation to transit to removed state done at each round) Feedback(evaluation to transit after receiving a message when node is aware of the update) Counter(transition is performed after a fixed number of rounds) Coin(transition is performed with a given probability at each round)

CASSANDRA

Nodes exchange information using a Gossip protocol about themselves and about the other nodes that they have gossiped about, so all nodes quickly learn about all other nodes in the cluster

Code Snippet Demo

Reference http://www.cs.cornell.edu/courses/cs6410/2016fa/slides/19-p2p-gossip.pdf http://disi.unitn.it/~montreso/ds/papers/montresor17.pdf http://www.inf.u-szeged.hu/~jelasity/ddm/gossip.pdf https://en.wikipedia.org/wiki/Gossip_protocol https://managementfromscratch.wordpress.com/2016/04/01/introduction-to-gossip/ https://www.linkedin.com/pulse/gossip-protocol-inside-apache-cassandra-soham-saha