Syntax: proxy_ssl_certificate file; Default: — Context: http, server, location This directive appeared in version 1.7.8. Specifies a file with the certificate in the PEM format used for authentication to a proxied HTTPS server.

Syntax: auth_request_set variable value; Default: — Context: http, server, location Sets the request variable to the given value after the authorization request completes. The value may contain variables from the authorization request, such as $upstream_http_*.

Syntax: worker_processes number | auto; Default: worker_processes 1; Context: main Defines the number of worker processes. The optimal value depends on many factors including (but not limited to) the number of CPU cores, the number of hard disk drives that store data, and load pattern. When one is in doubt, setting it to the number of available CPU cores would be a good start (the value “auto” will try to autodetect it). The auto parameter is supported starting from versions 1.

Syntax: proxy_cache_revalidate on | off; Default: proxy_cache_revalidate off; Context: http, server, location This directive appeared in version 1.5.7. Enables revalidation of expired cache items using conditional requests with the “If-Modified-Since” and “If-None-Match” header fields.

Syntax: scgi_intercept_errors on | off; Default: scgi_intercept_errors off; Context: http, server, location Determines whether an SCGI server responses with codes greater than or equal to 300 should be passed to a client or be intercepted and redirected to nginx for processing with the error_page directive.

Syntax: spdy_chunk_size size; Default: spdy_chunk_size 8k; Context: http, server, location This directive appeared in version 1.5.9. Sets the maximum size of chunks into which the response body is sliced. A too low value results in higher overhead. A too high value impairs prioritization due to HOL blocking.

Syntax: proxy_no_cache string ...; Default: — Context: http, server, location Defines conditions under which the response will not be saved to a cache. If at least one value of the string parameters is not empty and is not equal to “0” then the response will not be saved: proxy_no_cache $cookie_nocache $arg_nocache$arg_comment; proxy_no_cache $http_pragma $http_authorization; Can be used along with the proxy_cache_bypass directive.

Syntax: types_hash_bucket_size size; Default: types_hash_bucket_size 64; Context: http, server, location Sets the bucket size for the types hash tables. The details of setting up hash tables are provided in a separate document. Prior to version 1.5.13, the default value depended on the size of the processor’s cache line.

Syntax: scgi_temp_file_write_size size; Default: scgi_temp_file_write_size 8k|16k; Context: http, server, location Limits the size of data written to a temporary file at a time, when buffering of responses from the SCGI server to temporary files is enabled. By default, size is limited by two buffers set by the scgi_buffer_size and scgi_buffers directives. The maximum size of a temporary file is set by the scgi_max_temp_file_size directive.

Syntax: xslt_types mime-type ...; Default: xslt_types text/xml; Context: http, server, location Enables transformations in responses with the specified MIME types in addition to “text/xml”. The special value “*” matches any MIME type (0.8.29). If the transformation result is an HTML response, its MIME type is changed to “text/html”.