Mastering Nginx

Appendix A

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Directive Explanation Context/Default

valid_referers Defines which values of the

Referer header will cause the

$invalid_referer variable

to be set to an empty string.

Otherwise it will be set to 1. The

parameters can be one or more of

the following:

• none: There is no Referer
  header


• blocked: The Referer
  header is present, but
  empty or lacking a scheme


• server_names: The
  Referer value is one of the
  server_names


• arbitrary string: the value
  of the Referer header
  is a server name with or
  without URI prefixes and *
  at the beginning or end


• regular expression: matches
  the text after the scheme in
  the Referer header's value

Valid context: server,

location

Default value: -

variableshash
bucket_size

The bucket size used to hold the

remaining variables.

Valid context: http

Default value: 64

variables_hashmax
size

The maximum size of the hash that

holds the remaining variables.

Valid context: http

Default value: 512

worker_aio_requests The number of open asynchronous
I/O operations for a single worker
process when using aio with
epoll.

Valid context: events

Default value: 32

worker_connections This directive configures

the maximum number of

simultaneous connections that a

worker process may have open.

This includes, but is not limited to,

client connections and connections

to upstream servers.

Valid context: events

Default value: 512