[Blocks-development] suggestions - readvertisements

[Blat F. <pet...@ho...>]

>From: "Michael Spencer Jr." <bl...@ms...>
>To: "Erik Moeller" <mo...@sc...>,        
><blo...@li...>
>Subject: Re: [Blocks-development] Some suggestions
>Date: Sat, 5 Aug 2000 10:26:39 -0500
>
>I agree about mixing up the routing letters.  This sounds like a good idea.
>:)
>
>But remember that a lot of those 'inconvenient' features are very good for
>security -- file advert flooding (through too much traffic) becomes less of
>a problem if we don't rebroadcast file adverts so much.  Remember that this
>client that just connected to you might already have four other connections
>when you send your file list to him.

Yup, in V0.15, initial readvertisements are not forwarded. They
are just used to build an initial adverts.dat file. Im still
thinking about wether the slow readvertisement of files over
time should just be the same as initial adverts, similar to
readvertisements, or some new message type with slightly
different behaviour.

If they were just the same as initial readvertisements they
would slowly migrate from server to server over a long time,
but this would depend on how quickly we crawl through the
list. Say we readvertise one file every 30secs to each
connection (remember there are up to 16 connections so
this implies one ad every ~2 secs!)... then it would take
100000/2 = 50000 secs = ~14 hours to resend the whole
advert list. Which doesnt sound unreasonable.

>
>Leaving it as a user-configurable option is probably the best bet.  
>However,
>maybe sometime down the road the client program should keep track of which
>routes it's advertised to which connections, and not readvertise those
>routes.

This is slightly complicated by the fact that we're dealing
with a pretty big list (at the moment 100000) of adverts, but
thinking about it, if we only needed a single bit to store
a flag, we would only need 16*100000/8 = ~256Kb of memory for
this feature. Thats definately a real possibility.

I think this might even be a V0.16 feature! :)

>Also, if malicious clients become a problem someday, perhaps the
>client should automatically attempt to retrieve the header and some random
>blocks from a random subset of file adverts received over a link, to 
>confirm
>that the files being advertised exist...and drop the connection (and take
>other measures perhaps) if many or most of the files are bogus.


Im not sure that would scale well, the majority of the adverts
would be multiple hops away. prefer popular content be be
replicated.

Keep the suggestions and comments coming :)

ttfn

PG.

________________________________________________________________________
Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com