On 1/18/08 12:18 PM, "Colm MacCarthaigh" <[EMAIL PROTECTED]> wrote:
> Hmmm, it depends what you mean by scale really. Async doesn't help a > daemon scale in terms of concurrency or throughput, if anything it might > even impede it, but it certainly can help improve latency and > responsivity greatly. On the whole, it's easy to see how it might make > the end user experience of a very busy server much more pleasant. I also wonder is that has actually been tested or if it's just a "factoid"? >> Response time never increased in any measurable amount. > > I suspect it might though if the scheduler became bound, async would > route the interupts more efficiently. But, I wonder if the scheduler would become bound in a "reasonable" amount of traffic. > discussions on scalability baffling, the reality is that modern hardware > can outscale pretty much any amount of bandwidth you can buy regardless > of the software. Bandwidth generally isn't an issue for us anymore (thanks to gzip). We can still overrun the CPU with small objects requests/responses. On "large" objects (ie, over 16k or so), the CPU is bored when multiple gig interfaces are full. > The scalability wars should really be over, > everyone won - kernel's rule :-) Which is why I hate to see a ton of work go into async core if it actually does very little to help performance (or if it hurts it) and makes writing modules harder. It braindead simple nowadays to write well behaved high performance modules (well, mostly) bcs you rarely worry about threads, reads/writes, etc. Full async programming is just as challenging as handling a ton of threads yourself. My $.02 US worth (which ain't much). -- Brian Akins Chief Operations Engineer Turner Digital Media Technologies -- Brian Akins Chief Operations Engineer Turner Digital Media Technologies
