[Bitcoin-development] Scalability issues

grarpamp grarpamp at gmail.com
Mon Jul 23 22:33:24 UTC 2012


> You're seriously suggesting that I'm using a system
> which is 720x (one month vs one hour) faster than your
> P4 1.8GHz?

Don't know what you're using since you've not stated it.

> I find this doubtful, especially since bitcoin's sync is effectively
> single threaded.

Extra cores help with disk, crypto, net, etc...

> month

I've spent about two weeks crunching about the last month's
worth of new blocks.

> Your results are not expected and are not believed to be
> representative.

The config is reproducible, and not believed to be uncommon.

> try to isolate it

Mostly disk and crypto.
Shall everyone instead run in bitrot and no-privacy mode?
What do we do when we've got 10k trans a day coming in?
50k? 100k, 1M? When the chain gets 1M, 50M, 500M, 1B long?

Forget my swamped box, these numbers are coming to others.

> try to sync from a local node into tmpfs

I'd bet some people using 'tmpfs' probably have it unknowingly
[fall]backed to swap instead of core.

Bitcoin already takes up 3GiB of disk, how many have that much
free RAM? How many have 30GiB, 300GiB?

> If you're building against BDB later than the recommended 4.8
> be aware that there have been performance regressions with later
> versions

Yes, I left out that bit of platform so here are the remaining
bits... db4830, boost149, vm.kmem_size=650000000


I'm not bashing anything or anybody, just detailing a stock config
that is underwater. Anybody wishing to verify can get the hardware
from their junk pile and the software from freebsd.org. I'll certainly
be looking at both it and different setups too. If anyone's using
say Linux/BSD, BTRFS/ZFS, crypto, on i386/amd64, they could
chime in with their times too.

Disk is the cheapest, easiest thing for Joe to get. Think about
indexing and checkpointing into said disk. I don't know what
bitcoin's doing, but if it's verifying every transaction back to
the root, that would seem a bit ridiculous.

Joe probably won't be happy buying TiB's for bitcoind, so after that's
filled (assuming there's CPU to do it), the trust model has to change.
These scales are coming...




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