Proxy buffering query

Francis Daly francis at
Tue Aug 2 22:43:43 UTC 2022

On Tue, Aug 02, 2022 at 11:01:32AM -0400, libresco_27 wrote:

Hi there,

> What is the relationship between these three directives -
> proxy_busy_buffers_size, proxy_buffers and proxy_buffer_size?, plus some of the following sections.

> Currently, I'm only using proxy_buffer_size in my location block but
> whenever I set it to some higher number, for ex: 32k, it throws the
> following error -
> nginx: [emerg] "proxy_busy_buffers_size" must be less than the size of all
> "proxy_buffers" minus one buffer

If you have told nginx to use 20 kB of buffers; then also telling nginx
that it can have up to 40 kB of those buffers busy sending, is unlikely
to be a correct config.

I suspect that the error message is to ensure that you do not think that
you have configured more buffers than you actually have.


Francis Daly        francis at

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