[draft] MD-117: Ximen (Postconfirmations) Standards#117
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| - **Description**: Provides a set of liveness and correctness requirements for Postconfirmations protocols. | ||
| - **Authors**: [Liam Monninger](mailto:liam@movementlabs.xyz) | ||
| - **Approval**: :red-cross: |
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| - **Approval**: :red-cross: | |
| - **Approval**: |
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| **User journey**: Consumers of Ximen Postconfirmations consensus can rely on agreement to be achieved by a know Global Stabilization Time w.r.t. to the confirming ledger. | ||
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| **Justification**: A partially-synchronous protocol is a consensus protocol under FLP. While it does not render predictable points in time at which consensus will be known, it does prevent permanent asynchrony and unliveness. |
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it is not a protocol under FLP. FLP is discussing asynchronous protocols. Do you mean BFT?
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I think this is the same as #116 (comment). But, it's probably better to just refer to "Consensus in the Presence of Partial Synchrony."
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I don't think there is such a thing as a partially-synchronous protocol.
Partial synchrony is an assumption (a model of the network).
There are protocols that are consistent/valid/terminates under this assumption.
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We are tending towards defining a new name. for example quasi-partial synchronous. We mean that there will come a time after which "enough" voters are able to submit their votes within a bound time. This is rather similar to a partial synchronous model. Other words than quasi- are welcome. its just the first word that came to mind.
| **What can go wrong?** | ||
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| - Liveness may get stuck for epoch lengths. The L1 synchronizes the committee at epoch boundaries, and if enough committee members are honest and live eventually the protocol will be live again. | ||
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So overall, this sort implies that joining or leaving the set of voters must be handled carefully and requires synchronisation with the rounds on the L2?
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The committee is defined on the L1 and the L2 has the synchronize with the L1 iff there are fast confirmations. The number of rounds on the L2 to L1 mapping can be deterministic, e.g. every N L2blocks we submit a commitment to L1.
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@l-monninger i think we need explain more on epoch change being equal to some sort of view change more. Essentially as the epoch rollover updates the committee there may come a time (GST) when there is a committee that is live again and has the same view on the L2.
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Summary
MD-117