...

CONFIG proxy.config.http.origin_server_pipeline INT 16
CONFIG proxy.config.http.user_agent_pipeline INT 256

HTTP Background Fill Competion

There's an algorithm here that I don't fully understand, but this setting should guarantee that objects
loaded in the background are cached regardless of their size.

...

CONFIG proxy.config.http.cache.heuristic_lm_factor FLOAT 1.000000

HTTP Reverse Proxy Object Expiration Fuzzy Logic

I had to dig into the codebase for this one. Apparently this is a feature designed for reverse proxies
to "sweep" the cache at defined intervals. My memory's a bit foggy, so apologies if I got the definition wrong.
In any case, this functionality doesn't help a forward proxy cache whose goal is to keep objects in the cache.
The following setting disables this feature.

CONFIG proxy.config.http.cache.fuzz.min_time INT -1

Cache Minimum Average Object Size

This setting is pretty important. It defines a global variable whose function is to both structure the cache
for future objects, as well as optimize other areas. For my purposes, I decided an "average Internet object"
is roughly 32KB in size, and so we can do the following math:

Average Internet Object Size: 32KB
Disk Cache Size: 2GB
Disk Cache Size In Bytes: 2147483648 (2 * 1024 * 1024 * 1024)
Average Internet Object Size In Bytes: 32768 (32 * 1024)
Disk Cache Object Capacity: 65536 (2147483648 / 32768)

CONFIG proxy.config.cache.min_average_object_size INT 65536

NOTE: This setting should be sized relative to the size of your disk cache.
Also, it requires clearing the disk cache and restarting ATS.