On 7/3/12 3:51 AM, darrob wrote:

We've been using the multi-introducer patch on I2P since Tahoe-LAFS 1.8.3 and it has indeed proven to be more robust. The single-introducer grid we started out with simply fell apart when the introducer disappeared. It then took a long time before everybody learned the new introducer's address and adjusted their configurations. Time and files were lost. This hasn't happened again since we've started using the patched version.

The administrative burden is definitely there. However, I'd argue against it being worse. At least nodes that only know about a subset of introducers (e.g. only I2 in your example below) are in no rush of adding the rest (I3) because the grid is still functional.

Ah, that's an excellent data point. Thanks! Yeah, multi-introducers are a bit like RAID: you have more time to respond to a failure before the whole system starts having problems.

...

If you generalize this, then all nodes can function as introducers, and there's no need for dedicated Introducer nodes. As long as at least one node with a public IP is up at any given time, everybody else can learn the current state of the world.

This sounds perfect. I wonder if this system is susceptible to introducer spam attacks of some sort, though. I image those would be an annoyance at best.

Yeah, I think the worst-case attack is a DoS, where somebody floods useless information into the system. The key is the signed announcements: you may hear about all sorts of garbage, but you'll only pay attention to announcements that are signed by someone you've Invited, or who Invited you, or to whom you're transitively connected by Invitations. Ideally we can use that same criteria to limit how Announcements are flooded, so unrecognized garbage (i.e. "a stranger") doesn't travel further than a single node. cheers, -Brian _______________________________________________ tahoe-dev mailing list tahoe-dev@tahoe-lafs.org https://tahoe-lafs.org/cgi-bin/mailman/listinfo/tahoe-dev ----- End forwarded message ----- -- Eugen* Leitl <a href="http://leitl.org">leitl</a> http://leitl.org ______________________________________________________________ ICBM: 48.07100, 11.36820 http://www.ativel.com http://postbiota.org 8B29F6BE: 099D 78BA 2FD3 B014 B08A 7779 75B0 2443 8B29 F6BE