Re: [squid-users] squid performance epoll. 350req/sec 100% cpu
Ralf Hildebrandt wrote: * Stefan Neufeind [EMAIL PROTECTED]: Try compiling with the epoll-patch. Made an enormous performance-improvement here. System-time is wasted in the connection-handling (polling/select) - which is more efficient with epoll. Call me a retard, but where can I find this patch? Hi Ralf, see here: http://devel.squid-cache.org/projects.html I can also offer you a SRPM of the original Fedora FC4-release with epoll already integrated (needed a little tweaking). If you are interested, just let me know. Since you've still got my ICQ-contact afaik, just msg me :-) Regards, Stefan
Re: [squid-users] squid performance epoll. 350req/sec 100% cpu
Michal Mihalik wrote: Hello. I am tring to optimize squid for best possible performance. it is in production and it's doing more than 350req/sec. At peaks upto 500req/sec. My problem is only one. 100% cpu. :-) I tried to update my debian to 2.6.16 and recompiled squid: Squid Cache: Version 2.5.STABLE12 configure options: --prefix=/usr --exec_prefix=/usr --bindir=/usr/sbin --sbindir=/usr/sbin --libexecdir=/usr/lib/squid --sysconfdir=/etc/squid --localstatedir=/var/spool/squid --datadir=/usr/share/squid --enable-async-io --with-pthreads --enable-storeio=ufs,aufs,diskd,null --enable-linux-netfilter --enable-arp-acl --enable-removal-policies=lru,heap --enable-snmp --enable-delay-pools --enable-htcp --enable-epoll --enable-cache-digests --enable-underscores --enable-referer-log --enable-useragent-log --enable-auth=basic,digest,ntlm --enable-carp --with-large-files i386-debian-linux the thing I realy don't like is 25% cpu + 50% system cpu . why the 50% system! can anyone help? Try compiling with the epoll-patch. Made an enormous performance-improvement here. System-time is wasted in the connection-handling (polling/select) - which is more efficient with epoll. Regards, Stefan
Re: [squid-users] Non-cached pages with squid 2.5-stable13
Mark Elsen wrote: Hi Mark, thank you for that tool. It reports: http://[...]/cache/setHeader.php/getTheList Expires 35 sec from now (Sun, 19 Mar 2006 10:49:01 GMT) Cache-Control - Last-Modified 25 sec ago (Sun, 19 Mar 2006 10:48:01 GMT) validation returned same object ETag - Content-Length 6.3K (6438) Server Apache This object will be fresh for 35 sec. It has a validator present, but when a conditional request was made with it, the same object was sent anyway. I've read that squid might not be caching it, since the expires is less than 60 seconds in the future. Is that true? But even rasing the limit returned (currently 60 seoncds, maybe raising it to 120) does not work for me. What does the validation returned same object mean and why is it printed in read? Not sure, what is returned for this object with : http://web-sniffer.net ? Hmm - does not show anything special either. But during tries to track this down it showed that most of the time I received TCP_MEM_HIT, but sometimes a row of TCP_REFRESH_MISS occured for a duration of 10 or 20 seconds (1 request per sec) out of no obvious reason and only sporadic. It seems this occured with and without the collapsed forwarding-patch. I'll try to find a good way to reliable diagnose it before continuing this thread. Thank you for your help so far. Regards, Stefan
Re: [squid-users] Non-cached pages with squid 2.5-stable13
Mark Elsen wrote: On 3/19/06, Stefan Neufeind [EMAIL PROTECTED] wrote: Hi, at the moment I did try to run a squid 2.5-stable13 from Fedora Core 4, handpatched with collapsed-forwarding-support and epoll. Those two additional features work quite well. But currently I experience some pages which unfortunately are not cached by squid. ... ... http://www.ircache.net/cgi-bin/cacheability.py Hi Mark, thank you for that tool. It reports: http://[...]/cache/setHeader.php/getTheList Expires 35 sec from now (Sun, 19 Mar 2006 10:49:01 GMT) Cache-Control - Last-Modified 25 sec ago (Sun, 19 Mar 2006 10:48:01 GMT) validation returned same object ETag - Content-Length 6.3K (6438) Server Apache This object will be fresh for 35 sec. It has a validator present, but when a conditional request was made with it, the same object was sent anyway. I've read that squid might not be caching it, since the expires is less than 60 seconds in the future. Is that true? But even rasing the limit returned (currently 60 seoncds, maybe raising it to 120) does not work for me. What does the validation returned same object mean and why is it printed in read? Regards, Stefan
[squid-users] Non-cached pages with squid 2.5-stable13
Hi, at the moment I did try to run a squid 2.5-stable13 from Fedora Core 4, handpatched with collapsed-forwarding-support and epoll. Those two additional features work quite well. But currently I experience some pages which unfortunately are not cached by squid. I wonder why - and wonder if it might have to do with vary-headers the webserver is sending. A called script returns: Date: ... (current date) Server: Aapche Expires: ... (like date, approx 2min in the future) Last-Modified: ... (shortly before Date) Vary: Accept-Encoding Content-Length: ... Connection: close Content-Type: text/html The Vary-header is used to deliver gzip-compressed or non-compressed content (compressed inside php) to the clients which do/don't support it. Though I _think_ everything should be fine upon each request to squid for this object squid includes an If-Modified-Since in it's request which is already more than 2 hours in the past - might be the time when squid was started and/or first tried to cache a copy of the page. Both the squid and the webserver are in sync. Is there a possibility why squid does not cache the content, and why it might be using an IMS that far back in the past? Static content is cached fine - but that does not include Vary-headers or Expires. I've seen notes from (afaik) squid 2.5-stable11 that pages with vary-headers are now cached. Could this be related that in some special cases they are not yet? By the way: The squid is running in httpd_accel mode with proxy, in front of several webservers (which are in sync) defined via cache_peer. Any hints to track this down would be welcome! Yours sincerely, Stefan Neufeind
[squid-users] Performance-problems on reverse-proxy squid
Dear all, I'm running a squid-proxy (squid 2.5.stable7-1) in reverse-proxy mode in front of two webservers. Squid does equal loadbalancing across the servers, and answers requests for static pages/images/... itself. Because of the site-content squid is able to service about 80%-85% of the requests itself. Statistics report about 500 requests/second hitting squid, with an output to the internet of about 20mbit/s during peak-times. The squid-machine has an Intel Pentium IV 3,2GHz with two Intel Pro/1000-networkadapters (e1000-driver) on-board (one for outbound, one for internal network to the webservers). The system is running Fedora Core 3 with latest 2.6.x-kernel from Fedora. There are 2GB RAM available, with 1024MB allowed for squid, about 500MB of mem are used for filesystem-buffers, about 200MB used for kernel-buffer. Access to the harddisks is about 15 i/o writes per second, and a bit less read-i/o each. My problem is that during peak-hours the machine runs with very high cpu-utilisation. About 65% show up as being used by system. Unfortunately yet I wasn't able to isolate the bottleneck. I also used InterruptThrottleRate of the network-adapters to limit their interrupts and increased the Tx/RxDescriptors - without any change to cpu-utilisation. Does somebody have an idea how I could debug the cpu-utilisation of system, and how to lower it? Friends told me to watch out for possible buffers that could reduce the number of transfers from kernel-to-userspace or so - but I didn't find much. Feedback/help is _very_ much appreciated. Yours sincerely, Stefan Neufeind
