Hi Jean-Paul, that's a very interesting point of view and I have never thought about it this way, since I have a totally different background.
How would you go on about defining a min spec? Is this done by testing the software on different hardware configurations or are you looking at the requirements a priori? Best regards Henning On Wed, Jul 01, 2015 at 09:04:19PM -0700, Jean-Paul Kogelman wrote: > Hi folks, > > I’m a game developer. I write time critical code for a living and have to > deal with memory, CPU, GPU and I/O budgets on a daily basis. These budgets > are based on what we call a minimum specification (of hardware); min spec for > short. In most cases the min spec is based on entry model machines that are > available during launch, and will give the user an enjoyable experience when > playing our games. Obviously, we can turn on a number of bells and whistles > for people with faster machines, but that’s not the point of this mail. > > The point is, can we define a min spec for Bitcoin Core? The number one > reason for this is: if you know how your changes affect your available > budgets, then the risk of breaking something due to capacity problems is > reduced to practically zero. > > One way of doing so is to work backwards from what we have right now: Block > size (network / disk I/O), SigOps/block (CPU), UTXO size (memory), etc. Then > there’s Pieter’s analysis of network bottlenecks and how it affects orphan > rates that could be used to set some form of cap on what transfer time + > verification time should be to keep the orphan rate at an acceptable level. > > So taking all of the above (and more) into account, what configuration would > be the bare minimum to comfortably run Bitcoin Core at maximum load and can > it be reasonably expected to still be out there in the field running Bitcoin > Core? Also, can the parameters that were used to determine this min spec be > codified in some way so that they can later be used if Bitcoin Core is > optimized (or extended with new functionality) and see how it affects the min > spec? Basically, with any reasonably big change, one of the first questions > could be: “How does this change affect min spec?" > > For example, currently OpenSSL is used to verify the signatures in the > transactions. The new secp256k1 implementation is several times faster than > (depending on CPU architecture, I’m sure) OpenSSL’s implementation. So it > would result in faster verification time. This can then result in the > following things; either network I/O and CPU requirements are adjusted > downward in the min spec (you can run the new Bitcoin Core on a cheaper > configuration), or other parameters can be adjusted upwards (number of SigOps > / transaction, block size?), through proper rollout obviously. Since we know > how min spec is affected by these changes, they should be non-controversial > by default. Nobody running min spec is going to be affected by it, etc. > > Every change that has a positive effect on min spec (do more on the same > hardware) basically pushes the need to start following any of the curve laws > (Nielsen, Moore) forward. No need for miners / node operators to upgrade. > > Once we hit what we call SOL (Speed Of Light, the fastest something can go on > a specific platform) it’s time to start looking at periodically adjusting min > spec upwards, or by that time maybe it’s possible to use conservative plots > of the curve laws as a basis. > > Lastly, a benchmark test could be developed that can tell everyone running > Bitcoin Core how their setup compares to the min spec and how long they can > expect to run on this setup. > > What do you guys think? > > > jp > _______________________________________________ > bitcoin-dev mailing list > bitcoin-dev@lists.linuxfoundation.org > https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev -- Henning Kopp Institute of Distributed Systems Ulm University, Germany Office: O27 - 3402 Phone: +49 731 50-24138 Web: http://www.uni-ulm.de/in/vs/~kopp _______________________________________________ bitcoin-dev mailing list bitcoin-dev@lists.linuxfoundation.org https://lists.linuxfoundation.org/mailman/listinfo/bitcoin-dev
