I checked -- cached objects are not re-checked, at least not with two or three hours. But the memory usage is higher still without icap while the cache is still filling -- but this may due to the fact that I configured squid to cache objects only up to 1 MB and icap scans larger objects, too. Additionally squid does not know the icap scan limit, therefore every file will be sent to the ICAP server. So the higher memory usage will be probably the need of caching large objects, too, at least until ICAP has them scanned. Your thought with the two memory buffers may be another reason. OK, thank you, now I understand more clearly the extensive memory usage with ICAP. I will have to rethink whether ICAP is really the best way for what I want. Thank you again for your insight! Martin On 25.06.09 15:39, Martin.Pichlmaier@xxxxxxxxxxxxxxxxxxxxxxxxxxx wrote: > I have a question regarding memory usage for squid. I have 4 proxies, each > has about 200-400 req/s and 2-5 MB/s with ntlm_auth and about 1000 lines > of acl, > squid version is 3.0.STABLE15 on Redhat AS 5 Linux. > They are busy servers and therefore have no disk cache but memory cache of > 6144 MB (6 GB) and provide the internet access for some 10k users. [...] > The squid process needed about 7.5 to 7.8 GB and that seems reasonable. > After we enabled ICAP (c_icap with clamav virus scanning) the memory usage > of the squid process rose to about 12.8 GB. > > Is this a normal behaviour with squid when icap is enabled? It's quite possible that when icap is enables, squid must reserve some memory for icap i/o buffers. Although only one buffer may be teoretically needed, it's possible that squid uses two of them. the user memory highly depends on number and size of the uncached objects being accessed (i think cached objects aren't re-checked, are they?) -- Matus UHLAR - fantomas, uhlar@xxxxxxxxxxx ; http://www.fantomas.sk/ Warning: I wish NOT to receive e-mail advertising to this address. Varovanie: na tuto adresu chcem NEDOSTAVAT akukolvek reklamnu postu. WinError #98652: Operation completed successfully.