Quote from: CoinHoarder on January 24, 2016, 03:39:02 PM

Quote from: Fuserleer on January 24, 2016, 12:28:16 PM

Quote from: monsterer on January 24, 2016, 11:49:14 AM

The real problem with the idea of a decentralised exchange is not the technology, its the users.

Users do not care about decentralisation at all. The only thing they care about is convenience, fees, speed and security. DEX has great security, but fees will always be higher and speed will always be slower.

Correct, users don't care.

Plus, trade speed will be the critical problem that will prevent any DEX from seeing high volume, especially in the future.

I've spent quite a lot of time looking at ways to achieve high frequency trading (HFT) that is both secure and reliable (trades don't go missing, no "queue jumping"), and I don't think its possible to get < 5 second easily without some form of semi-centralization. When you compare traditional HFT exchanges such as the NYSE and others which are able to process trades sub-millisecond, well, our decentralized counterparts are never going to be able to compete as a serious alternative.

The fastest I've been able to get trades in our DEX with sufficient reliability is about 10 seconds, but that comes with quite a bit of overhead across the board in terms of bandwidth, processing and other costs.

Don't take this the wrong way, as I like you and your eMunie project, but I don't get this statement. You claim eMunie can process way more TPS than Bitshares, yet you can't get trades to settle on your DEX in less than 10 seconds? That doesn't make since to me. Bitshares settles trades in less than 4 seconds reliably. In fact, 4 seconds is the maximum amount of time and it usually takes around 2 seconds, but it does depend on when you click the confirmation but in relation to when the last block was produced. I suggest trying Bitshares' DEX. I think you will be impressed with the speed of settlement.

Also, I don't think anyone expects DEXs (at least as the technology is today) to realistically compete with the NYSE or other large HFT exchanges. I only expect them to compete with cryptocurrency exchanges in the near to immediate future. You can however trade stocks and commodities on Bitshares which is a benefit compared to most cryptocurrency exchanges.

Load handling isn't the same as settle or confirmation time, which is a completely different kettle of fish

It comes down to good old CAP and consensus. Assume there is a trade T with an ask of 100. User A submits a buy with a price of 100, User B also submits a buy with a price of 100 at exactly the same time but at the opposite end of the network. Which is the correct buy to apply? Some nodes will see A's buy first, apply it, and B's will be invalid, others will see B's first, apply it, and A's will be invalid. Then you end up in a conflict, half think A was first and is the correct buy to match that ask, the other half think B.

So while the initial acknowledgement can be very fast (sub 1 second), the duration to come to consensus is much longer and in some circumstances the original acknowledgement that A and B see may not be the one the network ultimately agrees on.

In the case of Bitshares, it has what I consider to be semi-centralization in the form of DPOS, which makes this task much easier to do quickly. Not only that, I doubt that Bitshares is seeing trading loads high enough yet to be triggering that scenario in the first place.

Bitshares also has very fast block times IIRC, and coupled with DPOS, they mitigate a lot of the problems that you have to deal with when doing the same in a fully decentralized system.

Is the Bitshares approach the right or wrong way? That depends what you want from the platform, if it does what it says on the tin and both they and the users are happy with it. If everyone is happy, then sure, why the hell not

Also I agree that HFT DEXs will probably never be required, but I spent a little time pushing the limits just so I knew where they were