Re: regarding software for linux!!

["Dr. P. Sriram" <sriram@xxxxxxxxxxxxxxxxxx>]

(actually, can be titled as how to get the most out of your bandwidth)

hi all,

i can do technical talking to any responsible person, but the strategy for
optimal bandwidth usage (as i recommend) would be slightly different. 
mirroring would not be the first item to be implemented. running a web
proxy would be the first item. our statistics show that running a proxy
increases external bandwidth utility by about 50% (i.e.)  about 65-70% of
requests will go out to get data and some 30-35 % will be served off the
cache; thus, with a proxy, an x mbps connection will function like a 1.5x
mbps connection since only 65-70 % requests will need to fetch data from
outside. there are tools available (transparent proxy) by which one can
automatically redirect all outgoing requests to a proxy. due to our
internal network topology, we do not have a need to run a transparent
proxy - all users have to use a proxy as the net is not directly
accessible. our 'main' proxy, a linux box (p2 at 233 with 64mb ram) rings
up about 2.5 lakh requests a day and serves some 2+ gigabytes per day
(this is about 10% of our available bandwidth). after this first step, the
next thing to do is to analyze the proxy statistics and see what sites are
used heavily (in terms of bytes per day, not requests per day) and at what
rate the information in the site changes. if the information change is
slow and download request rate is high, it would make sense to mirror.
however, for mirroring to actually lead to bandwidth savings, the required
differential between site information change rate and download rate is not
practical. mirroring can be used as a convenience for users (so downloads
can be faster) - i have not come across a situation where mirroring
can be shown to decrease bandwidth requirement.


sriram


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