Re: [Bitcoin-development] [ANN] High-speed Bitcoin Relay Network

[Mike Hearn <mike@plan99.net>]

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Very cool, thanks Matt.

I was actually thinking this morning, maybe we should require all nodes to
go through the inv/getdata dance. Otherwise it's possible to improve your
chances at racing a block by mining a block, waiting to see a block inv
from another node, then blasting out your block while other nodes are still
waiting on their getdatas.


On Wed, Nov 6, 2013 at 6:50 AM, Matt Corallo <bitcoin-list@bluematt.me>wrote:

> Recently, there has been a reasonable amount of discussion about the
> continued fragility of the public Bitcoin network on IRC and elsewhere
> (1). To this extent, I'm organizing a system of peering between nodes in
> the network by creating a system of high-speed relay nodes for miners
> and merchants/exchanges. This system will a) act as a fallback in the
> case that the public Bitcoin network encounters issues and b) decrease
> block propagation times between miners.
> It is NOT designed to in any way replace or decrease the need for the
> public Bitcoin P2P network. It is NOT any kind of attempt at
> centralization, and I still encourage interested parties to establish
> their own private peering agreements with large miners as needed.
>
> Currently the network consists of one specially-designed relay node, but
> I hope to bring more online in the coming days.
>
> This network is open to everyone via a few public relay nodes, but also
> will have nodes which are made available only to large miners and
> merchants/exchanges to mitigate the ability of malicious parties to DoS
> the network.
>
> To peer with the public relay nodes, simply select the closest region
> out of us-west (West Coast US), us-east (East Coast US), eu (Western
> Europe), au (Australia), or jpy (Japan) and add
> public.REGION.relay.mattcorallo.com to your addnode list. Note that
> since all of the relay nodes will relay between each other, you gain no
> latency advantage by peering with more than the closest node to you (and
> currently all the regions map to one node, so there they're redundant
> anyway).
>
> For each relay node, you can connect to either port 8334 or 8335.
> Connecting on port 8334 will relay only blocks, and port 8335 will relay
> both blocks and transactions. The relay nodes will request any
> transactions which appear in your invs no matter which port you connect to.
>
> Relay node details:
>  * The relay nodes do some data verification to prevent DoS, but in
> order to keep relay fast, they do not fully verify the data they are
> relaying, thus YOU SHOULD NEVER mine a block building on top of a
> relayed block without fully checking it with your own bitcoin validator
> (as you would any other block relayed from the P2P network).
>  * The relay nodes do not follow the standard inv-getdata-tx/block flow,
> but instead relay transactions/blocks immediately after they have done
> their cursory verification. They do keep some track of whether or not
> your nodes claim to have seen the transactions/blocks before relaying,
> but you may see transactions/blocks being sent which you already have
> and have not requested, if this is a problem for you due to bandwith
> issues, you should reconsider your bandwith constraints and/or are
> peering with too many nodes.
>  * The relay nodes will all relay among themselves very quickly, so
> there is no advantage to peering with as many relay nodes as you can
> find, in fact, the increased incoming bandwidth during block relay
> spikes may result in higher latency for your nodes.
>  * The relay nodes are NOT designed to ensure that you never miss data,
> and may fail to relay some transactions. Additionally, because the relay
> nodes do not respond to standard getdata requests, if you miss a relay
> and then reconnect, that data will not be sent again by the relay nodes.
> The relay nodes are NOT a replacement for having peers on the standard
> P2P network, they are only there to augment the existing P2P network.
>
> If you are a merchant/exchange/large miner/other important node operator
> and wish to gain access to additional domain names which map to relay
> nodes with fewer peers, please fill out the form at
>
> https://docs.google.com/forms/d/1UL82QdcXXEhZwSHJAK04Sk_cWg4zLOu8a216nO7Mt8c/viewform
>
> You can find the source for the relay nodes at
> https://github.com/TheBlueMatt/RelayNode
>
> If you have any comments/concerns/suggestions, please do not hesitate to
> email bitcoin-peering@mattcorallo.com
>
> Thanks,
> Matt
>
>
> (1) There has been extended discussion on #bitcoin-wizards as well as
> #bitcoin-dev of the very small number of active, listening nodes.
> Additionally, because many of those nodes are versions prior to 0.8.4,
> it seems very likely that maliciously creating network splits or at
> least drastically reducing the number of peers for most nodes would not
> be particularly challenging in the current network. Also,
>
> http://www.tik.ee.ethz.ch/file/49318d3f56c1d525aabf7fda78b23fc0/P2P2013_041.pdf
> noted that they were able to single-handledly decrease the network-wide
> orphan rate by around 50% by improving network peering. Finally, you've
> all seen the recent discussion on malicious mining algorithms. Though
> those are not entirely prevented by reducing block propagation times,
> they can be significantly limited compared to the current, rather
> disjoint, network.
>
>
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