Hi Amos, Thanks for the info. According to what you have mentioned below what do you think should be the value of cache_swap_low and high values to lower the load on the system although the hardware is big enough I think to hold such a load (all system us SAS based with 15k rpm drives and has 16GB of pyshical memory.) >That indicates that when the cache dir gets more than 95% full it needs >to clear at least 2GB of objects (2% of 115,000MB). > >Depending on your disks and avg object sizes this may be a large part of >the load. As for the regex acls since like I have said these specified by the videocache python squid plugin redirector setup I can try turning all of these off and see if the problem persists or no. And these regex acls are used only with below access lines url_rewrite_access deny videocache_deny_url url_rewrite_access allow videocache_allow_url url_rewrite_access allow videocache_allow_dom >A lot of those can be reduced to dstdomain or at least dstdomain >followed by a regex. > >ie: >acl A dstdomain .googlevideo.com >acl R urlpath_regex -i /videoplayback > >http_access allow/deny A R > >Using dstdomain (very fast test) at the start of an access line to >determine if the slower regex later on in the line is even needed can >produce a dramatic speed boost in response times. > >Where you are testing for file types the rep_mime_type on reply can >check the mime faster than a regex can test the entire URL. > >Also matching all of that file type by mime from a whole dstdomain can >be more effective and faster than a specific regex testing for a range >of specific sub-domains and file endings. > >Also you do not indicate which if the *_access lines these are being >tested in. It's a very good idea to only to them in one of either >http_access or http_reply_access, not both. Ragheb Rustom -----Original Message----- From: Amos Jeffries [mailto:squid3@xxxxxxxxxxxxx] Sent: Saturday, May 30, 2009 11:16 AM To: Ragheb Rustom Cc: squid-users@xxxxxxxxxxxxxxx; crobertson@xxxxxxx Subject: Re: squid2.7 Stable 6 passes in intervals where cpu usage hits 100% Ragheb Rustom wrote: > Hi Chris, > > Thank you for the reply. I will use squid -k debug to check what is going > on. > > As for the additional info sorry for not clearing the squid setup more > anyway this is squid configuration values you have guessed as taken from my > squid.conf > > Wild guesses based on the information given: > > *) You are using UFS for your cache_dir instead of AUFS. > > cache_dir aufs /cache1 115000 16 256 > cache_dir aufs /cache2 115000 16 256 > > I am using AUFS not UFS. > > *) Your cache is pretty large and your cache_swap_high and > cache_swap_low are still at the defaults > > cache_swap_low 93 > cache_swap_high 95 > > Do u think these values are reasonable enough regarding the above values of > my Cacche dir or should they be changed. > That indicates that when the cache dir gets more than 95% full it needs to clear at least 2GB of objects (2% of 115,000MB). Depending on your disks and avg object sizes this may be a large part of the load. > *) You are using large lists of regex ACLs > > acl videocache_allow_url url_regex -i \.youtube\.com\/get_video\? > acl videocache_allow_url url_regex -i \.googlevideo\.com\/videoplayback > \.googlevideo\.com\/get_video\? > acl videocache_allow_url url_regex -i \.google\.com\/videoplayback > \.google\.com\/get_video\? > acl videocache_allow_url url_regex -i \.google\.[a-z][a-z]\/videoplayback > \.google\.[a-z][a-z]\/get_video\? > acl videocache_allow_url url_regex -i > (25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9] > ?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][ > 0-9]?)\/videoplayback\? > acl videocache_allow_url url_regex -i > (25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9] > ?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.(25[0-5]|2[0-4][0-9]|[01]?[0-9][ > 0-9]?)\/get_video\? > acl videocache_allow_url url_regex -i > proxy[a-z0-9\-][a-z0-9][a-z0-9][a-z0-9]?\.dailymotion\.com\/ > acl videocache_allow_url url_regex -i vid\.akm\.dailymotion\.com\/ > acl videocache_allow_url url_regex -i > [a-z0-9][0-9a-z][0-9a-z]?[0-9a-z]?[0-9a-z]?\.xtube\.com\/(.*)flv > acl videocache_allow_url url_regex -i bitcast\.vimeo\.com\/vimeo\/videos\/ > acl videocache_allow_url url_regex -i > va\.wrzuta\.pl\/wa[0-9][0-9][0-9][0-9]? > acl videocache_allow_url url_regex -i \.files\.youporn\.com\/(.*)\/flv\/ > acl videocache_allow_url url_regex -i \.msn\.com\.edgesuite\.net\/(.*)\.flv > acl videocache_allow_url url_regex -i > media[a-z0-9]?[a-z0-9]?[a-z0-9]?\.tube8\.com\/ > mobile[a-z0-9]?[a-z0-9]?[a-z0-9]?\.tube8\.com\/ > acl videocache_allow_url url_regex -i \.mais\.uol\.com\.br\/(.*)\.flv > acl videocache_allow_url url_regex -i > \.video[a-z0-9]?[a-z0-9]?\.blip\.tv\/(.*)\.(flv|avi|mov|mp3|m4v|mp4|wmv|rm|r > am) > acl videocache_allow_url url_regex -i video\.break\.com\/(.*)\.(flv|mp4) > acl videocache_allow_dom dstdomain v.mccont.com dl.redtube.com > .cdn.dailymotion.com > acl videocache_deny_url url_regex -i http:\/\/[a-z][a-z]\.youtube\.com > http:\/\/www\.youtube\.com > > acl bad_requests urlpath_regex -i cmd.exe \/bin\/sh default\.ida?XXXXXXX > omg.pif > > acl music url_regex -i .wav > acl video url_regex -i .avi .mpe > acl cddown url_regex -i .iso .raw > > These are all the acl regex entries I use in my squid.conf file mainly most > of them are those of videocache. A lot of those can be reduced to dstdomain or at least dstdomain followed by a regex. ie: acl A dstdomain .googlevideo.com acl R urlpath_regex -i /videoplayback http_access allow/deny A R Using dstdomain (very fast test) at the start of an access line to determine if the slower regex later on in the line is even needed can produce a dramatic speed boost in response times. Where you are testing for file types the rep_mime_type on reply can check the mime faster than a regex can test the entire URL. Also matching all of that file type by mime from a whole dstdomain can be more effective and faster than a specific regex testing for a range of specific sub-domains and file endings. Also you do not indicate which if the *_access lines these are being tested in. It's a very good idea to only to them in one of either http_access or http_reply_access, not both. > > I will use the squid -k debug and try and get more info of what is going on > during the high cpu usage period and will share whatever I find on > squid-users mail list. > > Thanks Chris for your support. > > Ragheb > > -----Original Message----- > From: crobertson@xxxxxxx [mailto:crobertson@xxxxxxx] > Sent: Friday, May 29, 2009 10:18 PM > To: squid-users@xxxxxxxxxxxxxxx > Subject: Re: squid2.7 Stable 6 passes in intervals where cpu > usage hits 100% > > Ragheb Rustom wrote: >> Dear All, >> >> I have been noticing for some time now that my squid server passes in > nearly >> regular intervals during the day where the squid process CPU usage hits > 100% >> for around 20 - 30 seconds or so during which squid will not serve > requests. >> After these 20 -30sec the squid CPU usage drops to around 5 - 13% and >> website navigation is normal again. This happens like I said before at >> nearly regular intervals during each day several times and it happens only >> for around 20 -30sec. I have been observing the cache.log file but there > is >> nothing apparent there. Is there a way that I know what squid is doing > when >> this problem happens to try and resolve it as trying to solve it like it > is >> now with no info about what is going on is somewhat vague. > > squid -k debug > >> I think this >> problem happened after I have changed memory and disk replacement policies >> from lru to heap but I am not so sure that this is the source of the >> problem. I am using squid2.7-Stable6 on a fedora9 server which is a dual >> xeon quad 2.8Ghz CPU with 16Gb of Ram installed and 3 SAS hard drives. One >> more thing this server is also running videocache 1.9.1 but it has been >> running videocache also before the problem started with no problems >> whatsoever. I appreciate any help you can offer me. >> > > Wild guesses based on the information given: > > *) You are using UFS for your cache_dir instead of AUFS. > *) Your cache is pretty large and your cache_swap_high and > cache_swap_low are still at the defaults > *) You are using large lists of regex ACLs > >> Sincerely, >> >> Ragheb Rustom >> Smartelecom S.A.R.L >> Sin el fil - Mar Elias Street >> Absi Center - Ground Floor >> Beirut, Lebanon >> Email: ragheb@xxxxxxxxxxxxxxx >> > > Chris > > -- Please be using Current Stable Squid 2.7.STABLE6 or 3.0.STABLE15 Current Beta Squid 3.1.0.8 or 3.0.STABLE16-RC1
