Topic: Bitcoin 20MB Fork - page 123. (Read 154802 times)

I've been carefully reading replies. It is true that the average internet connection is quite "bad",but that does not matter. You can't just provide services to everyone in the world. Some people have internet speeds that are unbearable.
We either have to expand the size limit, or we have to find a way to compress the blockchain. Whichever these skeptics like more. 

What makes anyone think that the creator of Bitcoin left?

He has already answered this numerous times and it probably drives him crazy to keep hearing the same questions being repeated.

 The answer is we don't know Satoshi's true motivations for leaving but can only speculate.

From Gavin's notes he did test on a VPS successfully, but there is no mention of how long and the specs of the VPS. He even mentioned the larger blocks loaded 4 times faster on the VPS than smaller blocks (perhaps disk I/O related??)... very odd  . I'm sure the VPS is fine as Gavin was targeting a home computer and broadband connection as the goal, but am still curious to know the results.

IIRC, my 3Ghz Pentium D machine used about 30 hours of CPU time (20 hours wall time) to process about 20GB of block-chain (Bitcoin 0.8.3 or something). That works out to about 2 minutes per 20MB of transactions. Now I am wondering what machine they tested on. Even if I am off by 10GB, that is still less than 5 minutes per 20MB.

I don't think you can easily extrapolate a 20MB block cpu load average by looking at that data studying 32MB blocks under different conditions either.

I did some research and with one of my VPS's(I have some dedis and multiple VPS's )On one  I'm paying 10usd a month for 4 cores of Intel E3 CPUs 3.3GHz+ per core and per AUP I am allowed to use all 4 cores burstable and up to one of the cores for at least 1 hour continuously, thus one core running at 80% continuously on an Intel E3 CPUs 3.3GHz should be fine with a 10 usd /mo VPS.

Thus all we need to determine is if a single core 3.3GHz+ Intel can handle a node processing 20MB blocks.

My bitcoin node mostly had a dedicated connection to itself. I did not have a "soft cap": only a $5/GB penalty if I went over 300GB/month.



You were not the only one to wonder about specs. I think you can probably assume "Semi-modern Intel CPU with ~4 cores at ~3Ghz".

You are correct that many consumer ISP's use soft caps for monthly bandwidth and than severely reduce speeds.
This means that those that watch a lot of movies or torrent a lot may have problems. Somewhat a valid concern.


http://gavintech.blogspot.com/

"CPU usage should go down by a factor of about eight in the next release when we switch to Pieter's libsecp256k1 library for validating transactions. "

Additionally, the article you cite doesn't even give any details of the specs of the machine so it is impossible for me to draw any conclusions.

I am concerned about the continuous CPU load on a VPS because that will shut down the node. Where can I find this data? If a 10 dollar /month VPS cannot act as a full node than that would be troubling.

I think we should target somebody with a "pretty good" computer and a "pretty good" home internet connection.

And assume that network bandwidth, CPU and storage will continue to grow at about the rates they've been growing for the last 30 or more years (see the wikipedia pages on Moore's Law and Nielson's Law for pointers to discussions on those).

250gb per month is plenty for a 20MB block size
(20MB every ten minutes times 6 blocks per hour times 24 hours/day times 31 days/month == 90GB; we currently transmit all transaction data twice (haven't optimized that yet), so double that and you're still well under 250gb per month).


I believe it is extremely important to maintain the fundamental properties that Satoshi laid out -- because the system he described is the system that all of us who own bitcoin bought in to.

If the collective decision is to change some of those fundamental properties, then there must be extremely good reasons to do so.

On the block size issue, Satoshi said on Sun, 02 Nov 2008 on the metz-dowd cryptography mailing list (in reply to a question about scalability):

When I first heard about Bitcoin, it was small enough I could read everything, and I did, including all of those mailing list posts. The promise of a system that could scale up to rival Visa is part of the vision that sold me on Bitcoin.

I feel bad suggesting that we limit the block size at all, or that the target be home computers and internet connections -- but I think there are plausible concerns about centralization risk, and I think starting small and scaling up as technology advances is a reasonable compromise.

Those are "burstable" numbers, not average speeds based on data caps. Most of the world has a data cap of 250GB or less:
(250GB/month)/(30days/month)/(24hours/day)/(3600seconds/hour)*10bits/byte=965kbps averaged over the month.

In skimming the  article I linked, I saw that Japan's cap was the closest to the 2TB of potential data usage I mentioned in the other thread: allowing about 1TB/month.

My node had 5Mbps of burstable upload. However, to keep block propagation times down, I felt it was necessary to limit my blocks produced to 500kB. If blocks start approaching 20MB, I think any serious node will need at least 100Mbps of burstable upload bandwidth



For VPS, the bandwidth is not the problem. Your data center probably allows several providers to peer with each other: making your access cheaper. The problem with a VPS is that you will be asked to upgrade to a dedicated server if you use too much CPU time. How much CPU time does it take to verify a 20MB block?

About 6 minutes, 40 seconds.


Since you will be using more than half the CPU time, you will be asked to move to a dedicated server. I have found dedicated server hosting in Canada that allows 5TB of transfers for about $80/month. One reason I opted for the more expensive commercial Internet access is that I was able to plug Bitcoin hashers directly into the machine. I was not affected by the use of BGP to hijack my hahsers because my hashers were pointed at my own P2Pool instance in the same machine.

Even before the US started seizing domains, I have endeavored to keep my web-hosting outside the United States, where data is subject to the Patriot Act. Keeping my hosting in Canada also (ostensibly) means I don't have to worry about US law. (Some Tier 1 transit providers like CogentCo require Terms of Service language from web-hosts still requiring US law to be followed.) Staying in Canada means my bandwidth costs 10x as much. (Possibly due to the smaller population, but not certain.)

Edit: PS: I am laying out these numbers, not to argue against the fork, but to illustrate where the 1MB block proponents are coming from. I think 20MB blocks will be expensive, but necessary. The 1MB block supporters think that raising the block limit will simply kick the scaling problem down the road: while at the same time, making it harder to operate the network under the radar in the event of a crack-down.

You can already use a SPV and don't need to download the whole block-chain as Satoshi envisioned. The blockchain is currently ~32GB so those 500 GB HD should be fine for a while or you can add a 2TB hard drive for 60 bucks. Disk space is dirt cheap and most people upgrade regularly. Since you have such small hard drives did you realize that you should replace them every 3-4 years anyways because they now have a 10-30% failure rate depending upon the make/model? It is much safer to upgrade your computer regularly and sell the old one or convert those internals to externals than risk losing a portion of your data.

Are you sure you are even running as a full node by checking that your port 8333 is open(most people assume they are full node and aren't)?


Certainly not, I was simply providing real world data showing most home broadband users won't be effected by this.


He gets paid completely in bitcoin , of course he has to sell some. No one should be 100 invested in either fiat or bitcoin.

It's not just connection speed that will prevent normal people from running Bitcoin;  the best internet service I can get at my house has a 250gb monthly limit.

Also, I'm currently running full nodes on computers with 500GB hard drives.  Is that the message?  "Buy bigger computers and move somewhere that offers better internet service" ?

What kind of wallet will I be able to run, and will it depend on centralized servers?  If we can use a pruned blockchain or some kind of new wallet, could we please have these new wallets before any hard fork?

I understand that some changes may be necessary, but decentralization isn't one of the things that ever needs to be changed.

I'd like to trust Gavin, but he says he's been selling BTC.  That doesn't give me confidence in whatever changes he's planning.

Well, wide distribution is a nice thing but it fails in being a store of value. Someone should have told people not to buy the coins because "we need to wait until 2020".

I don't know if satoshi made a mistake or if people were just stupid for buying the coins.

Now tell me what sense is in wide distribution of worthless coins? Maybe there is sense in it but what sense does all your wishing and hoping have about the price?

I do have some serious discrepancies here about this whole bitcoin-thing and i honestly don't trust people to not screw it up even more. All the persona cult about satoshi and the intellectuals of these days is exaggerated. The intellectuals need to be questioned for their assumptions after what we currently see in the market.

You are cherry picking those stats and making some incorrect assumptions.

The reason I took a smaller figure is because your assumption entails that those 20MB will be at least 20-30% full. A VPS that costs between 5-10usd a month should be able to act as a full node no problem as well.

http://www.netindex.com/download/2,1/United-States/

A global avg for broadband upload is 9.9 Mbps
The data for the US reflects upload of 10Mbps
Avg upload for mobile in US is 6.2Mbps

I'm not citing advertised peak speeds either but real world data gathered independently.



5 dollars a month max for a VPS if they live in an unusual location with only shitty ISP's to choose from is a lot?

p.s... I am sorry that you have such slow Internet speeds, but be aware that you are the exception and not the rule and 5 dollars can host your own website, tor relay, and full node with no problem. I will even help you find a good VPS if you need to.

You mis-interpreted my post. My point was with 20MB blocks, you will no longer be able to host a node on consumer Internet Plans. The important number was not the 2Mbps download, but the 4Mbps upload. BTW, to get those numbers, I simply multiplied my former node's bandwidth usage by 20.

My current ISP has reduced the speeds it is offering for consumer access. The fastest upload offered on a consumer plan is 3Mbps. Business plans have an option with 5Mbps of upload. (Experiments like 250Mbps down and 15Mbps up are being grandfathered)

Telus, the local phone company, is better with it's VDSL offerings. You can get 5 or 10Mbps of upload speed. For independent providers (using the same lines), like the one I was with, your maximum upload speed is 5Mbps. To get 10Mbps or more, you have to go to fibre, costing $$$$. VDSL and cable may technically be able to handle that, but the companies involved don't want to cannibalize their lucrative fibre offerings.


My overall point is that if we go ahead with this fork, we have to do it with the understanding that the era of running a full node on a consumer Internet connection will be over. Due to extra CPU overhead (due to transaction processing), the days of running on a VPS may be over as well.

Now, with 20MB, I expect dedicated hobbyists and small businesses will still be able to run a node, but it will be a considerable expense: hundreds if not thousands per month. Webhosting may be cheaper, but then you can't keep an eye on your box; or plug hashers directly into it.

Exactly. The existing 1MB limit is not keeping the blocks at an average of 30% to 40% full today, just as it was not keeping them 10% full three years ago. If the block size limit became 20MB tomorrow then it might still be four years before the first 20MB block occurs, and five years before they are common.


This worries me too. It is a serious risk. Once the blocks are an average of 75% full the network goes into a red-zone where a bunch of deliberately small or empty blocks can pile up the unconfirmed tx causing delays of hours for confirmations. It is a very cheap attack. Just sent some coins to an exchange to sell? Come back tomorrow if this attack is in progress. Yet some people are more worried about a few 20MB spam blocks being mined, which the network would hardly notice.

Satoshi is the one who decided on Bitcoin's high inflation rate in the early years, which I believe was (wisely) done to distribute the currency widely; Bitcoin, or any currency, is more valuable the more users it has.

Development discussions currently happen on the IRC channel for Bitcoin, the development mailing list, the /r/bitcoin subreddit at Reddit, and this very forum (more serious discussions usually are to be found in the Development & Technical section).

Is that the same people/group debating and doing the thinking that's responsible for the high inflation too? Where is your elitist circle having discussions exactly? Would love to witness that fun. You have failed before more than once #justsayin'

and bandwith, centralizing the whole thing.

for all i know, bitcoin is no cash, bitcoin is no gold, we dont know what it is yet (or i honestly dont), and mass adoption should not matter in the sense that they will get what usually get: what they are told to.