large number of cache files

[Roger Fischer]

Hello,

from a practical perspective, what would be considered an unreasonable large number of cache files (unique cache keys) in a single nginx server?

1M, 10M, 100M?

With a large cache, would there be any significant benefit in using multiple caches (multiple key_zones) in a single nginx server?

Or using two nginx servers on the same physical server (or VM)?

I am aware of the ~ 8K keys (files) per 1 MB of key zone memory, and that available memory thus poses a limit. I am curios at what point the the cache exceeds the comfort zone of the design.

Thanks…

Roger