As mentioned before, try the new version of calamaris (v2.99). There is a new report included, which shows you in the 'Requested extensions' report some nice information about object freshness: - ratio fresh/stale - ratio unmod/mod This helps you to improve your squid refresh_pattern.
Michael On Thu, 2004-12-02 at 22:39, Adam Aube wrote: > Martin Marji Cermak wrote: > > > I have been playing with Squid under a heavy load and there are some > > stats. I am trying to maximise the "Byte Hit Ratio" value. I got 13% > > average, but I am not happy about this number - I want it higher > > To increase your byte hit ratio, you can: > > 1) Switch to one of the heap cache replacement policies > 2) Tune your refresh_pattern settings to make Squid cache more aggressively > > See the FAQ and default squid.conf for details on these items. > > However, before going through the tuning, run an analysis tool (such as > Calamaris) on your logs to see what your traffic pattern is like. This will > show you what a reasonable byte hit ratio would be. > > If, for example, 70% of your traffic is dynamic content (which usually > cannot be cached), then a 13% byte hit ratio is actually pretty good. > > > USED HARDWARE: > > Processor: P4 1.8GHz > > Memory: 1 GB > > Hardisk: 40 GB IDE 7200rpm > > > Requests: 180 req/sec (peak), 60 req/sec (day average). > > According to posts from Squid developers, a single caching Squid box has an > upper limit of about 300 - 400 requests/second. This isn't too bad, > considering you are using a single IDE disk for the entire system. > > > maximum_object_size 51200 KB (SHOULD I MAKE IT HIGHER ???) > > Actually, you might want to make it lower. Most web requests will not be for > 50 MB files, and your byte hit ratio will be hurt if a 50 MB file that is > requested once forces out fifty 1 MB files that are accessed twice each. > > The default is generally acceptable, unless log analysis shows large numbers > of requests for larger files. > > > cache_dir aufs /cache 25000 16 256 > > You should size your cache to hold about a week's worth of traffic. Just > watch your memory usage (1 GB of cache ~ 10 MB of memory for metadata). > > > cache_mem 8 MB > > This is generally fine - the OS will generally use free memory to cache > files anyway, which will have the same effect as boosting this setting. > > > I am going to install a new box with SCSI disks so I will report to you > > how the performance will change. > > Best disk performance will be achieved with multiple small, fast SCSI disks > dedicated to Squid's cache, each with its own cache_dir (no RAID), and > round-robin between the cache_dirs. > > Adam
