I hate to speak for someone else, but I believe that Tim may have been referring to the tendency of some people to use threads without understanding their limitations. (I've seen attempts to massively thread CPU-bound applications on single CPU machines.)
Threads are not magic that can be spread on a program to make it "better". That being said. Tim did not say "don't" he asked "why".<grin/> That's much politer than I've normally been to people in a similar circumstance. <shrug/> G. Wade [EMAIL PROTECTED] wrote: > > > From: Tim Funk <funkman () joedog ! org> > > Subject: Re: [Q] Is it safe to create threads in Tomcat web-apps? > > > You can create threads all day in tomcat, but here are the importnatn things > > to consider: > > > - WHY! Are threads really the correct solution? > > - And last but not least: WHY! Are threads really the correct solution? > > I'm getting the impression that you think multiple threads are never > the right answer. :) That's not necessarily true. > > Suppose that your response to a request contains three steps which are > independant of one another; in order to deliver a faster response > time, you'd like to execute them concurrently. > > If these three steps are CPU-bound, then the amount of benefit really > depends on the machine; you need multiple CPUs so that the scheduler > can run the different threads on different CPUs. With a single CPU, > you're not likely to see much benefit. > > However, if the three steps are IO-bound, using multiple threads to > run them concurrently can lead to a big improvement. Most of the time > spent doing IO is spent waiting. (Particularly if the IO is network > IO, a "sub-request" to a remote site, for example). If the idle times > occur concurrently instead of serially, you'll certainly do better. > > -- > Steve > > --------------------------------------------------------------------- > To unsubscribe, e-mail: [EMAIL PROTECTED] > For additional commands, e-mail: [EMAIL PROTECTED] --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
