I keep reading about how mongo's use of memory mapped files is real bad. Isn't that the same technique used by varnish cache and that's what makes it awesome? Can someone explain please?
Varnish has a much simpler access pattern (which happens to fit the page-cache semantics like a glove in almost all use-cases) and was developed by a drastically more competent team.
Comparing varnish to mongodb is akin to comparing a precision Rolex from Swiss to a plastic mickey mouse watch from a gumball machine.
