Opened 4 years ago

Closed 4 years ago

#2085 closed enhancement (duplicate)

The relationship between directive "fastcgi_busy_buffers_size" and other two directives is not recorded clearly.

Reported by: zhoushulin1992@… Owned by:
Priority: minor Milestone:
Component: documentation Version: 1.18.x
Keywords: Cc: zhoushulin1992@…
uname -a: Linux xlarge 4.15.0-72-generic #81-Ubuntu SMP Tue Nov 26 12:20:02 UTC 2019 x86_64 x86_64 x86_64 GNU/Linux
nginx -V: nginx version: nginx/1.18.0
built by gcc 7.4.0 (Ubuntu 7.4.0-1ubuntu1~18.04.1)
configure arguments: --prefix=/usr/local/nginx --with-pcre=/root/Downloads/pcre-8.43


In the document of directive "fastcgi_busy_buffers_size", it says that "By default, size is limited by the size of two buffers set by the fastcgi_buffer_size and fastcgi_buffers directives". Indeed, based on the handling logic in src/http/modules/ngx_http_fastcgi_module.c, the value of "fastcgi_busy_buffers_size" must be equal or greater than the maximum of the value of "fastcgi_buffer_size" and "fastcgi_buffers" size. So it is recommended to add this information in the doc of "fastcgi_busy_buffers_size"(

The same situation happens in directive "fastcgi_temp_file_write_size" in, and directive "fastcgi_max_temp_file_size" in They should all be equal or greater than the maximum of the value of "fastcgi_buffer_size" and "fastcgi_buffers" size.

What's more, the value of directive "fastcgi_busy_buffers_size" must be less than (number-of-fastcgi_buffers - 1)*size-of-fastcgi_buffers. This also should be recorded.

Change History (1)

comment:1 by Maxim Dounin, 4 years ago

Resolution: duplicate
Status: newclosed

Closing this as duplicate of #2086, which is more generic, as applies to proxy.

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