another cool wart
Tom Anderson (tom@emigrant)
Wed, 3 Jun 1998 13:04:52 -0700 (PDT)
One other nice experiment: congestion is likely to happen in
the middle of a large download. What if we could switch download
sites in the middle of a download. Is there an experiment we could
run that says: "We have downloaded 7 MB of this 15 MB file and we
have now run into congestion or a network partition so we are going
to switch over to this other server for the rest of the file. How
often is this a win? How big a win is it? I don't think there is
support for such an operation in current HTTP specification. Maybe
the right way to go about this is retrieving multiple large files
(100 KB) from a replicated service. Start with one service and
with performance slows down switch to another service. Maybe some
random percentage of downloads always go to a backup and as we
start to observe better performance from a backup server we start
to send more and more of the requests to the backup server (important
to maintain stability).
In the PC tech column yesterday in the NYT, the columnist described
spending 3 hours downloading a new software app (Outlook) from
Microsoft. He tried getting it from Microsoft, and it crashed
halfway through; he tried getting it from some mirror in California, and it
crashed halfway through. He ended up downloading it from New Zealand!
tom