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trying to create a leader election protocol with my specifications but i fail. Let me describe more detail.

Let's imagine we have 5 nodes A,B,C,D,E and let's also assume that all of them compete to solve a puzzle something like PoW but for our scenario is irrelevant. Let's also assume that both C,D solve simultaneously the puzzle and send the proofs for verifications in the other nodes.

  1. A[C2,D3]

  2. B[C4,D2]

  3. E[C3,D6]

Nodes A,B,E receives messages from C,D. For example node A receives a message from C at timestamp 2 and from D at timestamp 3 it also verifies proofs that C,D solves the puzzle successfully.

What i am searching for now is to pick the fastest node from the winners C,D and recognize him as the leader of the protocol. As a result, they all exchange their messages and they average the times to find the winner node with the smallest time. if randomly pick node B it will calculate the time for C [4+2+3]/3=3, D[3+2+6]/3=3,6.

Hence every node will calculate time 3 for C and time 3,6 D and finally, they choose C with the lowest timestamp as a leader.

Am i correct until now does this process has logic?

My big problem now is what happened if B node is malicious and try to trick the protocol and send different values to A,E this will confuse all node so they cannot reach a consensus. How can we fix this and pass this step?

Can anyone give me any idea?

Mixalis Navridis
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1 Answers1

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Falsehoods programmers believe about time applies. Particularly the bits about trusting the system clock.

The first good algorithm for leader election was Paxos. A number of others have emerged since. See here for a partial list.

Getting distributed programming right is hard. In the past decade, Jepsen has analyzed a lot of systems. In the overwhelming majority of cases the guarantees that the authors thought they could validly give about how their systems would fail were wrong. You shouldn't expect to beat that average. Therefore I strongly recommend that you delegate leader election to proven software such as Zookeeper rather than trying to roll your own implementation.

btilly
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  • First of all thnx for anwersing to my question i appreciate it that. I have a question Paxos uses three phases Prepare phase,accept,commit. Lets also assume that in my protocol where i described i have a coordinator or leader to initiate the phase of paxos and move on. My question is how to reach consensus on timestamps if A,B,E have different data can you be more specific to my problem? It is important from me to somehow find the faster one – Mixalis Navridis May 31 '22 at 14:57