On Wed, May 09, 2007 at 01:30:41AM -0400, Daniel Ouellet wrote: > No swapping is happening, even with 1000 httpd running. > > load averages: 123.63, 39.74, 63.3285 01:26:47 > 1064 processes:1063 idle, 1 on processor > CPU states: 0.8% user, 0.0% nice, 3.1% system, 0.8% interrupt, 95.4% > idle > Memory: Real: 648M/1293M act/tot Free: 711M Swap: 0K/4096M used/tot >
How does this server do with 1000 non-httpd processes running? Perhaps I need a newer Nemeth et al, but in my 3rd edition, pg 759 middle of the page says "Modern systems do not deal welll with load averages over about 6.0". Could your bottleneck be in context-switching between so many processes? With so many, the memory cache will be faulting during the context switching and have to be retreived from main memory. I don't think that such slow-downs appear in top, and I don't know about vmstat. I don't know if there's a tool to measure this on i386. I've never run httpd but it looks to me like a massivly parralized problem where each connection is trivial to serve (hense low CPU usage, no disk-io waiting) but there are just so many of them. How does the server do with other connection services, e.g. pop or ftp? Doug.
