ngx_http_core_module

Tengine added some enhancements to this module. The new directives are listed below.

Directives

Syntax: listen 443 ssl http2 spdy Default: - Context: server

Define checking whether client supports HTTP v2 or SPDY v3 protocol with ALPN or NPN, and Tengine will select a protocol to deal with SSL offload, from HTTP v2, SPDY v3, and HTTP v1.x, in order of such priority.

Syntax: client_body_buffers number size Default: 16 4k/8k Context: http, server, location

Specify the number and size of buffers used when reading non buffered client request body, all the buffers are stored in the memory. Buffers are allocated only on demand. By default, the buffer size is equal to your OS's pagesize. The total buffer size should be larger than client_body_postpone_size, otherwise, it will be enlarged by force.

Syntax: client_body_postpone_size size Default: 64k Context: http, server, location

When you turn off the proxy_request_buffering or fastcgi_request_buffering, Tengine will send the body to backend either it receives more than size data or the whole request body has been received. It can save the connection and reduce the network system call number with backend.

Syntax: proxy_request_buffering on | off Default: on Context: http, server, location

Specify the request body will be buffered to the disk or not. If it's off, the request body will be stored in the memory and sent to backend after Tengine receives more than client_body_postpone_size data. It can avoid the disk IO with large request body.

By default in the buffered mode, the whole request body larger than the client_body_buffer_size will always be saved into the disk. This behavior may increase the server load greatly with heavy upload application.

Note that, if you turn it off, the nginx retry mechanism with unsuccessful response will be broken after you sent part of the request to backend. It just returns 500 directly when it encounters an unsuccessful response. This directive also breaks these variables: $request_body, $request_body_file. You should not use them any more while their values are incomplete.

Also note that, enabling spdy will prevent proxy_request_buffering off from taking effect.

Syntax: fastcgi_request_buffering on | off Default: on Context: http, server, location

The same as proxy_request_buffering.

Syntax: resolver address ... [valid=time] [ipv6=on|off]; Default: -- Context: http, server, location

Tengine will parse nameserver in /etc/resolv.conf as DNS server when resolver is not assigned.

Syntax: gzip_clear_etag on | off Default: on Context: http, server, location

Determines whether gzip module should clear the “ETag” response header field.