It is to be used as a bitmask with various bits set/reset when appropriate.
Any bit set means that the peer should not be used, that is, exactly what
current checks do, no additional changes required.
All the errors that prevent loading configuration must be printed on the "emerg"
log level. Previously, nginx might silently fail to load configuration in some
cases as the default log level is "error".
The ssl_preread module extracts information from the SSL Client Hello message
without terminating SSL. Currently, only $ssl_preread_server_name variable
is supported, which contains server name from the SNI extension.
In this phase, head of a stream is read and analysed before proceeding to the
content phase. Amount of data read is controlled by the module implementing
the phase, but not more than defined by the "preread_buffer_size" directive.
The time spent on processing preread is controlled by the "preread_timeout"
directive.
The typical preread phase module will parse the beginning of a stream and set
variable that may be used by the content phase, for example to make routing
decision.
Previously, it was not possible to use the stream context
inside ngx_stream_init_connection() handlers. Now, limit_conn,
access handlers, as well as those added later, can create
their own contexts.
Previously, it was possible that some system calls could be
invoked while holding the accept mutex. This is clearly
wrong as it prevents incoming connections from being accepted
as quickly as possible.
Keeps the full address of the upstream server. If several servers were
contacted during proxying, their addresses are separated by commas,
e.g. "192.168.1.1:80, 192.168.1.2:80".
The stream session status is one of the following:
200 - normal completion
403 - access forbidden
500 - internal server error
502 - bad gateway
503 - limit conn
If the range includes two or more /16 networks and does
not start at the /16 boundary, the last subrange was not
removed (see 91cff7f97a50 for details).
If PCRE is disabled, captures were treated as normal variables in
ngx_http_script_compile(), while code calculating flushes array length in
ngx_http_compile_complex_value() did not account captures as variables.
This could lead to write outside of the array boundary when setting
last element to -1.
Found with AddressSanitizer.
