install squid

install:
sudo apt-get update
wget http://www.squid-cache.org/Versions/v4/squid-4.8.tar.gz
tar xvzf squid-4.8.tar.gz
cd squid-4.8
sudo apt-get install build-essential
sudo apt-get install autoconf g++ python2.7-dev
sudo apt-get install libssl-dev
./configure --with-openssl --enable-ssl-crtd
make
sudo make install
#It will install everything to /usr/local/squid

CACHE_DIR: "cache_dir aufs Directory-Name Mbytes L1 L2 [options]"
	- install pthread for "aufs"
	sudo apt-get install libpthread-stubs0-dev
	- DIskd works perfectly on some OS'es, like Solaris, BSD.
	- Linux-based OS, AFAIK, works with diskd so slow. And AUFS is the best choise in this case. Depending system settings, of course.
	- "We should set L1 and L2 high enough so that directories at the second level don't have a huge number of files"
	- example with 50Gb cache: cache_dir aufs /squid_cache/ 51200 32 512
		+ assume the average size of a cached object to be 16 KB --> 51200x1024÷(32x512x16) = 200 cached objects in each of the directories at the second level which is quite good.

Cache object size limits:
	- "we can set the maximum limit to something around 100 MB, which will make sure that the popular software, audio/video content, and so on, are also cached, which may lead to significant bandwidth savings"
	- "minimum_object_size 0 KB"
	- "maximum_object_size 96 MB"

Cache Swap:
	- The default is 90 and 95 %, which are good if the size of cache directory is low (like 10 GB). If we have a large amount of space for caching (such as a few hundreds GBs), we can push the limits a bit higher and closer
	- "cache_swap_low 96"
	- "cache_swap_high 97"

	- "cache_replacement_policy heap LFUDA" choose algorithm to delete object cache