- From: Jeffrey Mogul <mogul@pa.dec.com>
- Date: Tue, 20 Dec 94 16:42:52 PST
- To: Rob McCool <robm@neon.mcom.com>
- Cc: http-wg%cuckoo.hpl.hp.com@hplb.hpl.hp.com
I agree... for instance, I'm not sure how I would implement something to keep track of how idle multiple server processes are without using shared memory or writable mmap()ed files, which I already have found are not available on certain platforms we support... Well, I have some suggestions. Have Netscape send a check to Digital, and I'll share them with you :-). I'm not sure where the demand for this is either... The generality of a session seems to me to be not that great a win if the session is still a batch request-response cycle. I'd rather have real sessions similar to what Simon proposes in HTTP-NG, where we can have interactive stock quotes streaming in through one window while at the same time the user is browsing the same server's other HTML documents, all in one connection. This is the kind of situation where I could imagine it would be better to use two TCP connections, instead of trying to multiplex one. That is, if you have enough data flow to amortize the costs of two connections, then it's probably worth following that relatively simple approach, instead of going through all the work of implementing HTTP-NG. Yes, and to that end we have to keep in mind that while <img width=N height=M> is useful, it means that in order to see that performance win, everyone has to edit their HTML. That will take time, and Netscape's perceived performance works everywhere without having to edit (or parse) every single HTML doc on a server... This is only true if one believes that Netscape's perceived performance is independent of network dynamics. Which is, I believe, an open question. My own intuition is that we can follow two paths: (1) Stick with the parallel connection approach, which gives reasonably good performance today but which might turn into a global performance disaster in the future. (2) Encourage people to shift ASAP to an alternative (besides the WIDTH and HEIGHT tags, several HTTP-level mechanisms have been proposed). This might avert future global problems, but in the short term it might be a while before enough servers support it to make it highly beneficial. I would also expect that in the long run (i.e., with widespread support), it would improve UPP because you wouldn't have to wait even for the initial bits of the images to arrive. This dilemma is similar to the global warming issue: do we reduce CO2 emissions now, or do we wait and see if the icecaps really will melt? And are there other benefits to reducing emissions, beyond averting global warming? -Jeff
Received on Tuesday, 20 December 1994 16:52:07 UTC