Time To First Byte and proxy_buffering

[Maxim Dounin]

Hello!

On Mon, Oct 24, 2011 at 11:17:05PM +0100, Jonathan Matthews wrote:

> Does "proxy_buffering on" (especially when it'll definitely buffer to
> disk) imply that the client will *not* be sent the first part of the
> response until nginx has received and buffered the entire response
> from the upstream server?

No.

> Or does/can the upstream response buffering
> happen in parallel with the client-side response being sent?

Yes.

There is a caveat though: individual buffers (see proxy_buffers 
directive) will be sent to client only once they are fully filled.  
And that's why "proxy_buffering off" exists: it allows pass all 
data without any delay even if buffer isn't yet filled, as this 
may be critical in some use cases (streaming, some server push 
cases).

Maxim Dounin