This commit removes frontend-tls parameter, and adds
redirect-if-not-tls parameter parameter to --backend option. nghttpx
now responds to the request with 308 status code to redirect the
request to https URI if frontend connection is not TLS encrypted, and
redirect-if-no-tls parameter is used in --backend option. The port
number in Location header field is 443 by default (thus omitted), but
it can be configurable using --redirect-https-port option.
We have added "dns" parameter to backend option. If specified, name
lookup is done dynamically. If not, name lookup is done at start up,
or configuration reloading. nghttpx caches DNS result including error
case in 30 seconds in this commit. Later commit makes this
configurable.
DNS resolution is done asynchronously using c-ares library.
std::make_shared in Xcode 7, 7.1, and 7.2 does not perform
value-initialization, and causes undefined behaviour if struct does
not have user defined default constructor. This workaround explicitly
defines user defined default constructor, and initializes values.
Previously, we didn't retry request on connection failure. Sometimes
we hit the edge case where connection is about to lost just when we
write request. To avoid this situation, we now retry request to
failed attempt. We also add ConnectBlocker to MemcachedConnection not
to attempt to connect to memcached if connection could not be made
previously.
To reduce TTFB with large number of incoming connections, we now
intentionally accept one connection at a time, so that it does not
delay the TTFB of the existing connection. This is significant
especially for TLS connections.
Suppose the wildcard patterns follows:
- *.nghttp2.org/foo
- *.img.nghttp2.org/bar
Previously, s.img.nghttp2.org/foo does not match anything. Now it
matches first pattern.
The --backend-tls-sni-field is deprecated in favor of sni keyword.
--backend-tls-sni-field still works, and it overrides all sni keyword
in --backend option. But it will be removed in the future release.
It is very hard to support multiple protocols in backend while
retaining multiple mode settings. Therefore, we dropped modes except
for default and HTTP/2 proxy mode. The other removed modes can be
emulated using combinations of options. Now the backend connection is
not encrypted by default. To enable encryption on backend connection,
use --backend-tls option.
Previously, we use one Http2Session object per DownstreamAddrGroup.
This is not flexible, and we have to provision how many HTTP/2
connection is required in advance. The new strategy is we add
Http2Session object on demand. We measure the number of attached
downstream connection object and server advertised concurrency limit.
As long as former is smaller than the latter, we attach new downstream
connection to it. Once the limit is reached, we create new
Http2Session object. If the number lowers the limit, we start to
share Http2Session object again.
This commit changes nghttpx's mruby script handling. Previously we
have 2 options to specify the mruby script file to be run on request
and on response. Now they are merged into 1 option, namely
--mruby-file. It now must return object. On request, the object's
on_req(env) method is invoked with env object. Similarly, on
response, the object's on_resp(env) method is invoked. The
specification of Env object has not changed.
The control process handles signals, reads configuration, reads
private keys, and bind port (which may be privileged one). It never
drop privileges, so that it can execute new binary with the same
privilege. It forks worker process. The worker process handles all
incoming connections. It drops privilege.
To achieve host-path backend routing, we changed behaviour of
--backend-http2-connections-per-worker. It now sets the number of
HTTP/2 physical connections per pattern group if pattern is used in -b
option.
Fixes GH-292
-b option syntax is now <HOST>,<PORT>[;<PATTERN>[:...]]. The optional
<PATTERN>s specify the request host and path it is used for. The
<PATTERN> can contain path, host + path or host. The matching rule is
closely designed to ServeMux in Go programming language.
Currently, we use same number of HTTP/2 sessions per worker with given
backend addresses. New option to specify the number of HTTP/2 session
per worker will follow.
When same SSL_CTX is used by multiple thread simultaneously we have to
setup some number of mutex locks for it. We could not check how this
locking affects scalability since we have 4 cores at best in our
development machine. Good side of sharing SSL_CTX across threads is
we can share session ID pool.
If --tls-ctx-per-worker is enabled, SSL_CTX is created per thread
basis and we can eliminate mutex locks. The downside is session ID is
no longer shared, which means if session ID generated by one thread
cannot be acceptable by another thread. But we have now session
ticket enabled and its keys are shared by all threads.
Tatsuhiro Tsujikawa