Mastering Nginx

Appendix A

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Directive Explanation Context/Default

proxy_buffers The number and size of buffers

used for responses from upstream

servers.

Valid contexts: http,

server, location

Default value: 8

4k|8k (platform

dependent)

proxy_busybuffers
size

The total size of buffer space

allocated to sending the response

to the client while still being read

from the upstream server. This

is typically set to two proxy_

buffers.

Valid contexts: http,

server, location

Default value: 8k|16k

(platform dependent)

proxy_cache Defines a shared memory zone to

be used for caching.

Valid contexts: http,

server, location

Default value: off

proxy_cache_bypass One or more string variables,

which when non-empty or non-

zero, will cause the response to be

taken from the upstream server

instead of the cache.

Valid contexts: http,

server, location

Default value: -

proxy_cache_key A string used as the key for storing
and retrieving cache values.

Valid contexts: http,

server, location

Default value:

$scheme$proxy_

host$request_uri

proxy_cache_lock Enabling this directive will
prevent multiple requests from
making an entry into the same
cache key.

Valid contexts: http,

server, location

Default value: off

proxy_cachelock
timeout

The length of time a request will

wait for an entry to appear in the

cache or for the proxy_cache_

lock directive to be released.

Valid contexts: http,

server, location

Default value: 5s