thx for your reply amos 2013/10/2 Amos Jeffries <squid3@xxxxxxxxxxxxx>: > On 2/10/2013 10:02 p.m., Jérôme Loyet wrote: >> >> Hello, >> >> I'm facing a particular situation. I have to set-up a squid cluster on >> 10 server. Each server has a lot of RAM (192GB). >> >> Is it possible et effective to setup squid to use only memory for >> caching (about 170GB) ? > > > memory-only caching is the default installation configuration for Squid-3.2 > and later. > is there any problem by setting cache_mem to 170GB ? > >> What directive should be tweaked ? (cache_mem, >> cache_replacement_policy, maximum_object_size_in_memory, ...). The >> cache will store object from several KB (pictures) up to 10MB (binary >> chunks of data). > > > All of the above memory cache parameters. (cache_replacement_policy is disk > parameter, but there is memory_cache_replacement_policy instead). > > cache_mem and maximum_object_size_in_memory in particular. The default is > for only small objects to be memory cached. > > > >> With 10 sibling cache squid instances, what should I use as type of >> cache peering ? (10 siblings or a multicast ICP cluster, other ?) > > > With memory cache holding under-32KB objects SMP workers would be best. They > share a single memory cache, but it is size limited to 32KB memory pages due > to Squid internal storage design. I'm not sure yet whether the work underway > to extend Rock storage past this same limit is going to help shared memory > cache as well (hope so, but dont know). I'm planning to set up one squid instance on each of the 10 servers. As the server won't be dedicated to squid, I want to limit squid to run on one single process (no SMP). > > For now, if you want larger objects to server from memory you will be best > off with a CARP cluster or HTCP sibling configuration for now. > > NP: I recommend staying away from ICP with Squid-3.2 and later. We have not > yet changed the defaults, but ICP has a very high false-positive hit rate on > HTTP/1.1 traffic. HTCP is more bandwidth hungry on the UDP but far better on > HIT rate. what's your opinion about multicast for sharing cache ? > > Amos
