* Amos Jeffries <squid3@xxxxxxxxxxxxx>: > Ralf Hildebrandt wrote: > >3.0.STABLE25 is showing the following behaviour during normal operation: > > Hi Ralf, > Thank you for all this, but I'm wondering why you are putting so > much work into 3.0? 3.1 sucks even more? See my other bug reports! That stuff is crashing all over the place. Need to get some stability here :) > I ask because the major performance gains are aimed at 3.2. It could > do with this type of analysis as part of the polish up. I COULD run 3.2 if you like. > Okay, add to that a sudden extreme loss of known clients. And a > sudden 'instant' drop in memory usage before the growth. > > This looks to me like the usual culprit: > A Squid crash followed by dirty rebuild of a large caches' index. Could be > The behaviour in such a situation is complete non-response on the > ports for a short period (extreme service times for existing clients, > they simply get no further traffic and time out). Yes, but that should only be a problem for the clients. > Followed by a period of heavy reads as the entire cache_dir get > scanned file-by-file for meta data to build the index. Some of which > will fail as the un-closed files from previous instance are found. > Accompanied by heavy writes as the swap.state journal gets rebuilt > from each of those meta-data reads. > > Under heavy client load this extra disk IO can lead to delays > processing other actions and slower new client service times. OK, but for such a long time? > Potentially a huge backlog of buffered in-transit data waiting to be > stored in the cache. Which can't be written to until the index is > loaded properly. > > This latter can be alleviated by a sufficiently large in-memory > cache, though older versions did not permit that space to be used > until after the rebuild either. > > >proxy 10426 88.5 17.3 380636 357040 ? R 10:42 110:54 /usr/sbin/squid3 -NsYC > > > >% strace -c -p 10426 > > Over how long a time was the strace taken? just that 1.6 seconds or > something longer? That trace is from about 15 seconds. -- Ralf Hildebrandt Geschäftsbereich IT | Abteilung Netzwerk Charité - Universitätsmedizin Berlin Campus Benjamin Franklin Hindenburgdamm 30 | D-12203 Berlin Tel. +49 30 450 570 155 | Fax: +49 30 450 570 962 ralf.hildebrandt@xxxxxxxxxx | http://www.charite.de
