# each backend must listen on a unique port
# without this the CARP algorithm would be useless
http_port localhost:400${process_number}

# a 10 GB cache of small (up to 32KB) objects accessible by any backend worker
cache_dir rock /mnt/cacheRock 10240 max-size=32768

# NP: for now AUFS does not support SMP but the CARP algorithm helps reduce object duplications
# a 10 GB cache of large (over 32KB) objects per-worker
cache_dir aufs /mnt/cache${process_number} 10240 128 128 min-size=32769

# the default maximum cached object size is a bit small
# you want the backend to be able to cache some fairly large objects
maximum_object_size 512 MB

# you want the backend to have a small cache_mem
cache_mem 4 MB

# the backends require a different name to frontends, but can share one
# this prevents forwarding loops between backends while allowing
# frontend to forward via the backend
visible_hostname backend${process_number}.example.com

# change /var/log/squid to your own log directory
access_log /var/log/squid/backend${process_number}.access.log
cache_log /var/log/squid/backend${process_number}.cache.log

# add just enough access permissions to allow the frontend
http_access allow localhost