[tor-dev] Load Balancing in 2.7 series - incompatible with OnionBalance ?

teor teor2345 at gmail.com
Wed Oct 21 23:13:48 UTC 2015

> On 21 Oct 2015, at 10:22, Alec Muffett <alecm at fb.com> wrote:
> typo:
>> alecm: and this persists for up to 24h, even though the outage was only 10 minutes
> Also, I neglected to observe that linear polling of A-E seeking a descriptor suggests A will be hammered whilst J is nearly idle.

Do you mean "seeking an introduction"?

Do we connect to introduction points in the order they are listed in the descriptor? If so, that's not ideal, there are surely benefits to a random choice (such as load balancing).

That said, we believe that rendezvous points are the bottleneck in the rendezvous protocol, not introduction points.

However, if you were to use proposal #255 to split the introduction and rendezvous to separate tor instances, you would then be limited to:
- 6*10*N tor introduction points, where there are 6 HSDirs, each receiving 10 different introduction points from different tor instances, and N failover instances of this infrastructure competing to post descriptors. (Where N = 1, 2, 3.)
- a virtually unlimited number of tor servers doing the rendezvous and exchanging data (say 1 server per M clients, where M is perhaps 100 or so, but ideally dynamically determined based on load/response time).

In this scenario, you could potentially overload the introduction points.

> Some entropy in IP selection would be a good thing.

I agree!


More information about the tor-dev mailing list