http://zzz.i2p/topics/840-originally-installed-0-8-3-and-earlier-eepsite-correlation
It specifies a maximum number of threads for the pool handling HTTP requests, and specifies the name of that pool ("main"). If a user copies that jetty.xml file to make additional eepsites and does not change the pool name, the additional eepsites will use the same pool, with common thread min, max, and idle time settings.