On Tue, Jan 6, 2009 at 10:42 PM, Florent Daigniere
<nextgens at freenetproject.org> wrote:
> Matthew Toseland wrote:
>> On Tuesday 06 January 2009 12:15, Florent Daigniere wrote:
>>> Matthew Toseland wrote:
>>>> On Wednesday 31 December 2008 14:23, Matthew Toseland wrote:
>>>>> #1: 41 votes : release the 20 nodes barrier
>>>>>
>>>>> "most of the users nowadays have a lot of upload-bandwith available.
>> Myself
>>>>> has about 3Mbits upload, but the limit to connect to not more than 20
>> nodes
>>>>> results in about 50kb/s max. Please release the limit or use a dynamic
>>>> system
>>>>> that offers more connections if the node has a high bandwith upload limit
>>>>> (scaling). Thx"
>>>>>
>>>>> I'm not sure what to do about this. The original rationale for the 20
>> peers
>>>>> limit was that we didn't want to disadvantage darknet nodes too much on a
>>>>> hybrid network, since they will not often have large numbers of peers.
>>>>> Combined with experience on 0.5 suggesting that more peers is not always
>>>>> better, a security concern over over-reliance on ubernodes, and the fact
>>>> that
>>>>> we should eventually be able to improve bandwidth usage through better
>> load
>>>>> management. However, there's a limit to what we are able to achieve
>> through
>>>>> better load management, and it's a difficult problem.
>>>>>
>>>>> Thoughts?
>>>> As people have pointed out, many people only have access to very slow
>>>> connections. Vive seems to think there is no theoretical problem with
>>>> this ... so the remaining questions:
>>>> - What should the minimum number of peers be?
>>>> - What should the maximum number of peers be?
>>>> - How much output bandwidth should we require for every additional peer?
>>>>
>>>> For the first, a safe answer would be 20, since that's what we use now;
>>>> clearly it won't seriously break things. IMHO less than 1kB/sec/peer is
>>>> unreasonable, but I might be persuaded to use more than that. And we
>> probably
>>>> should avoid adding more peers until we've reached the minimum bandwidth
>> for
>>>> the lower limit. Vive suggested a limit of 50, I originally suggested
>> 40 ...
>>>> probe requests continue to show approximately 1000 live nodes at any given
>>>> time, so we don't want the upper limit to be too high; 100 would certainly
>> be
>>>> too high.
>>>>
>>>> One possibility then:
>>>>
>>>> 0-20kB/sec : 20 peers
>>>> 21kB/sec : 21 peers
>>>> ...
>>>> 40kB/sec+ : 40 peers
>>>>
>>>> Arguably this is too fast; some connections have a lot more than 40kB/sec
>>>> spare upload bandwidth. Maybe it shouldn't even be linear? Or maybe we
>> should
>>>> have a lower minimum number of peers?
>>>>
>>>> 0-10kB/sec : 10 peers
>>>> 12kB/sec : 11 peers
>>>> 14kB/sec : 12 peers
>>>> ...
>>>> 70kB/sec : 40 peers
>>>>
>>> Yay, more alchemy!
>>
>> More alchemical than an arbitrary 20 peers limit? I suppose there are more
>> parameters...
>
> See below; it's not about changing the alchemy; it's about changing it now.
>
>>> What's the reason why we are considering to raise the limit again?
>>
>> To improve performance on opennet, in the average case, for slow nodes, and
>> for fast nodes?
>>
>>> It's
>>> not the top-priority on the uservoice thingy anymore. Anyway, I remain
>>> convinced that ~50 votes is irrelevant (especially when we consider that
>>> a single user can give 3 voices to the same task!) and that we shouldn't
>>> set priorities depending on what some "vocal" users are saying.
>>>
>>> They are concerned by their bandwidth not being sucked up? Fine! Turn
>>> them into seednodes, create a distribution toadlet, create a special
>>> mode where they would only serve UoMs (and would be registered by
>>> seednodes as such)... They are plenty of solutions to max out their
>>> upload bandwidth usage if that's what they want their node to do!
>>
>> Don't you think that more opennet peers for fast nodes, and maybe fewer for
>> really slow nodes, would improve performance for everyone?
>
> Fewer peers for slow nodes would help in terms of latency; I'm not sure
> about more for fast nodes.
>
>> Given that our
>> current load management limits a node's performance by the number of its
>> peers multiplied by the average bandwidth per peer on the network?
>>
>
> IMHO it's a lot more trickier to do than to bump one constant! Anyway,

ugh.....
Did anybody notice we have this dynamic already?

r19603 Scale so 20 peers at 16K/sec.
r19602 Scaling of peers with bandwidth

That's in April 2008.

> that's not the point: the point is you're about to merge a new
> client-layer AND considering to change yetAnotherParameter which might
> have network wide effects in the meantime. All of that in a short
> timeframe and right before a release (unless I missed something the
> release is still planned for "soon")!
>
> It's bad practice.
>
> Suppose things get screwed up (or drastically improve): how will you say
> which of your changes have caused it? It's not like the theoreticians
> knew for sure what the effects are going to be: they said "it shouldn't
> break things" ... not that it won't or can't.
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