On 9/03/2016 6:49 a.m., Cohen-Rose, Adam wrote: > > We¹re planning to test how switching to an SMP config affects performance > ‹ will hopefully post our results when we see them. > Thanks. That would be good to see. > > One remaining puzzle: we see the latency creep upwards overnight when the > traffic drops ‹ reaching 140ms when it¹s normally 25ms. Is this just an > artefact of the servers being lightly loaded? > Yes. Squid processing is driven by I/O cycles. Which have a 10m timeout. When there is no (or low) I/O happening, Squid can do its non-I/O processing parts of the transactions with up to that 10ms delay on each cycle. There is also a much increased packet overhead as each tiny bit of I/O that needs doing has a whole lot of CPU speed to push it through the proxy really fast. In some extreme cases that can result in lots of 1-byte packets, but usually it just means smaller packets. Amos _______________________________________________ squid-users mailing list squid-users@xxxxxxxxxxxxxxxxxxxxx http://lists.squid-cache.org/listinfo/squid-users
