On Thu, Jun 2, 2011 at 12:45 AM, Amos Jeffries <squid3@xxxxxxxxxxxxx> wrote: > On 02/06/11 18:27, Tory M Blue wrote: >> >> Afternoon >> >> Have a question, is there a negative to running -k rotate more than >> once a day? > > All your active connections will pause while Squid deals with the logs. > Ahh wasn't aware thanks, but it seems to be pretty quick, so not sure this is terrible :) >> I've recently moved squid to a ramcache (it's glorious), however my >> cache.swap file continues to grow and brings me to an uncomfortable >> 95%. > > By "ramcache" do you mean RAM cache (aka a large cache_mem storage area) or > an in-memory pseudo disk? > > Tried using COSS? (in-memory pseudo disk with hardware backing). In memory psuedo-disk /dev/ram0. I tried Coss before and it was a really bad experience, wonder if I try it with the pseudo-disk instead of on hard disk (I setup coss before using standard fast SAS disks (not memory) and it was slower then sin, really bad, 20-30 seconds for the first image etc. Maybe what you are saying is I did my test wrong and COSS should be used with a in memory "pseudo-disk", like what I'm running now with aufs.. hmmm >> >> If I run rotate it goes from 95% to 83% (9-12gb cache dir), it seems I >> need to run this once every 12 hours to stay in a good place, but is >> there anything wrong with that? I don't see it and seems that the >> rotate really just cleans up the swap file and since it's all in ram, >> it's super fast. > > That should be fine even if its was on disk. High throughput networks are > known to do it as often as every 3 hours with only minor problems. > I've only heard of one network doing it hourly, the pause there was > undesirable for the traffic being handled. > There is a nasty little feedback loop: the faster to *have* to do it the > worse is the effects when you do. It is economical, up to a point. > > >> >> Another option is to move the swap file to a physical disk, what type >> of performance hit will my squid system take? Obviously it's just >> looking up, reading hash so it should not cause any issues, but >> wondered. What is my best option, keep everything in ram and run >> rotate 2-3x a day or is the penalty so small that pushing the swap >> file to a physical disk a better answer? > > Unsure. Try it and let us know. > > The swap.state is a journal with small async writes for each file operation > (add/remove/update of the cache_dir), including those for temporary files > moving through. You only get into problems if the write speed to it falls > behind the I/O of the cache its recording. (in general, on average etc.. > Peak bursts should not be a big problem) > Squid can recover from most swap.state problems. But it is best to avoid > that kind of thing becoming normal. > > HTH Always thank you sir. Tory > Amos > -- > Please be using > Current Stable Squid 2.7.STABLE9 or 3.1.12 > Beta testers wanted for 3.2.0.8 and 3.1.12.2 >
