From: http://wiki.squid-cache.org/SquidFaq/SquidMemory#How_much_memory_do_I_need_in_my_Squid_server.3F

As a rule of thumb on Squid uses approximately 10 MB of RAM per GB of the total of all cache_dirs 
(more on 64 bit servers such as Alpha), plus your cache_mem setting and about an additional 10-20MB. 
It is recommended to have at least twice this amount of physical RAM available on your Squid server.

From: http://curl-loader.sourceforge.net/

curl-loader (also known as "omes-nik" and "davilka") is an open-source tool written in C-language, 
simulating application load and application behavior of thousands and tens of thousand HTTP/HTTPS 
and FTP/FTPS clients, each with its own source IP-address. In contrast to other tools curl-loader 
is using real C-written client protocol stacks, namely, HTTP and FTP stacks of libcurl and TLS/SSL 
of openssl, and simulates user behavior with support for login and authentication flavors.

The goal of the project is to deliver a powerful and flexible open-source testing solution as a real 
alternative to Spirent Avalanche and IXIA IxLoad.

From: http://www.comfsm.fm/computing/squid/FAQ-6.html

These are taken from RFC 2616 and verified for Squid. Squid-2 uses almost all codes except 
307 (Temporary Redirect), 416 (Request Range Not Satisfiable), and 417 (Expectation Failed).

From: http://wiki.squid-cache.org/SquidFaq/SquidLogs

The Squid result code is composed of several tags (separated by underscore characters) which 
describe the response sent to the client.