The testcaches tool simulates multiple ATS caches' _astats endpoints.
Its primary goal is for testing the Monitor under load, but it may be useful for testing other components.
A list of parameters can be seen by running ./testcaches -h. There are only three: the first port to use, the number of ports to use, and the number of remaps (delivery services) to serve in each fake server.
Each port is a unique fake server, with distinct incrementing stats.
When run with no parameters, it defaults to ports 40000-40999 and 1000 remaps.
Stats are served at the regular ATS stats_over_http endpoint, _astats. For example, if it's serving on port 40000, it can be reached via curl http://localhost:40000/_astats. It also respects the ?application=system query parameter, and will serve only system stats (the Monitor “health check” [as opposed to the “stat check”]). For example, curl http://localhost:40000/_astats?application=system.