Re: [GSoC 23] distributed substitutes, cost of storage

[Simon Tournier <zimon.toutoune@gmail.com>]

Hi,

Please skip if it interferes in the discussion. :-)  That’s just my
partial understanding as a ignorant person on this topic of P2P storage
system.


First of all, thanks for considering the two architectures of P2P
storage networks: (1) one node publishes their local content or (2) one
node publishes a chunk of the global content.

Between all the drawbacks and/or difficulties of (2), one corollary
feature appears to me interesting: enforcing a policy for the global
that allows redundancy and so never lost some data.  À la
git-annex-numcopies [1].

However, I am still missing how Swarm-like could help…


On Fri, 07 Apr 2023 at 22:45, Attila Lendvai <attila@lendvai.name> wrote:

> this page also has a much shorter whitepaper:
>
> https://www.ethswarm.org/why
>
> it started out as a storage layer for Ethereum, and as such one of its
> main task is to store the blockchain data, but it's not limited to
> that. there's nothing special about the blockchain data from this
> perspective, and reflecting that, the Swarm project is not under the
> Ethereum umbrella anymore.

… Thanks for the pointer.

Well, I do not understand how Swarm-like does not rely on some
cryptocurrency, here BZZ for Swarm itself.  Since Swarm-like enforces
that I must store data that I do not care, then because it is a strong
constraint by the system, somehow it breaks my altruism and I only would
do such by being financially compensated – what they implement:

        p.1
        Swarm is a peer-to-peer network of nodes that collectively
        provide a decentralised storage and communication service. This
        system is economically self-sustaining due to a built-in
        incentive system which is enforced through smart contracts on
        the Ethereum blockchain and powered by the BZZ token.

        p.2
        Built-in incentives seek to optimise the allocation of bandwidth
        and storage resources and render Swarm economically
        self-sustaining. Swarm nodes track their relative bandwidth
        contribution on each peer connection, and excess debt due to
        unequal consumption can be settled in BZZ. Publishers in Swarm
        must spend BZZ to purchase the right to write data to Swarm and
        prepay some rent for long term storage.

        p.7
        As nodes relay requests and responses, they keep track of their
        relative consumption of bandwidth with each of their
        peers. Within bounds peers engage in a service-for-service
        exchange. However, once a limit is reached, the party in debt
        can either wait until their liabilities are amortised over time,
        or can pay by sending cheques that cash out in BZZ on the
        blockchain (see figure 5).

        [...]

        Nodes are financially motivated to help each in relaying
        messages, because each node that successfully routes a request
        closer to the destination earns BZZ when the request was
        successfully served. If that node is not storing the data
        itself, it pays a small amount of money to request chunks from
        an even closer node. By doing such trades, nodes earn a little
        profit when serving a request. This implies that nodes are
        motivated to cache chunks as, after purchasing the chunk once
        from a closer node, any subsequent requests for the same chunk
        will earn pure profit.

        p.8
        A contract on the blockchain allows advance purchase of a
        postage batch for BZZ tokens. A batch entitles the owner to
        issue a limited number of stamps. These stamps then serve as a
        fiduciary signal indicating how much it is worth for a user to
        persist the associated content in Swarm. By using this value to
        prioritise which chunks to remove from the reserve first, storer
        nodes maximise the utility of the DISC (see figure 6).

    From the whitepaper: <https://www.ethswarm.org/swarm-whitepaper.pdf>.


Other said, if the underlying cryptocurrency does not have a financial
value – what it would be the case, IMHO, for some Swarm-like system
applied to Guix – then I am not convinced that this “way“ to solve the
free-rider problem is better (more sustainable) than other P2P system as
IPFS-like, Torrent-like, GNUnet-like, etc.


>> However, somehow, I am not convinced that Guix should introduce some
>> mechanisms to tackle some free rider problems [3].
>
> isn't the main task of every p2p storage solution to tackle the free
> rider problem? 

Yes, it is the task of P2P storage system.  Is Guix one P2P storage
solution?  Or should Guix exploit already implemented P2P storage
systems?

Cheers,
simom

1: https://git-annex.branchable.com/git-annex-numcopies/