[…] > client<->squid : 31Mbps.
[…] > Squid<->server : 28Mbps > > Total: 59Mbps. > > Which is slightly higher than the known "good" performance limit for > Squid-3.1. Which is up to ~50Mbps, tuning both in Squid and the system can > reach around 100Mbps IIRC. But that sort of numbers you are looking at > specific traffic types as well. Ah ! Thank you very much for this valuable figures. 50Mb/s is not what I was really hoping/expecting. I was naively thinking that Squid can handle multi 100Mb/s out of the box (at least with no ACLs, and other fancy stuff) We have 2x100Mb/s Internet connections in front of this proxy. >> select_loops = 2316.561716/sec > <snip> >> syscalls.sock.reads = 1316.883520/sec >> syscalls.sock.writes = 1770.096831/sec > > It looks like sending and receiving data in ~2KB chunks, just over one packet > per cycle. > >> syscalls.sock.recvfroms = 58.203913/sec >> syscalls.sock.sendtos = 30.974986/sec >> cpu_time = 117.934176 seconds >> wall_time = 300.048557 seconds >> cpu_usage = 39.305030% > > CPU usage at 40%. > > Squid-3.1 does use around 30% CPU to push data at line rate, which is what > this set of counters seems to be showing. We have done a bunch of work aimed > at improving things all over Squid in the more recent releases, if you want > to assist the developers tracking this down please upgrade to the latest > release before delving too deeply into the analysis as all fixes need to go > in through 3.HEAD anyway and you maybe repeating already done work (only > might there is still CPU issues hiding in the latest development code). Point taken, I'll do that. > What do things look like when its at or close to 100% CPU? Basically, some users complain about browsing slowing down. But the main complaint is about download speeds of "large" files (~50MB -> GB) (but this can be explaind by the natural limits of Squid) > Also any sign of the OS swapping virtual memory when the CPU climbs? that is > a known performance killer for a number of reasons we can't fix easily. Already checked this area, no swapping involved. > Amos Youssef
