Thanks for the responde Maxim, I appreciate it.

In our case we're not using perl modules and we're not serving files either. We're using a bunch of known lua/resty libraries (we're using openresty), but AFAIK all IO in lua is non-blocking.

On the other hand, that 75s delay in processing was just the example I pasted, we saw cases where it took almost 3m to respond.

Thanks