If cache was bypassed with proxy_cache_bypass, cache-controlling headers
(Cache-Control, Expires) wasn't considered and response was cached even
if it was actually non-cacheable.
Patch by John Ferlito.
Configuration with duplicate upstream blocks defined after first use, i.e.
like
server {
...
location / {
proxy_pass http://backend;
}
}
upstream backend { ... }
upstream backend { ... }
now correctly results in "duplicate upstream" error.
Additionally, upstream blocks defined after first use now handle various
server directive parameters ("weight", "max_fails", etc.). Previously
configuration like
server {
...
location / {
proxy_pass http://backend;
}
}
upstream backend {
server 127.0.0.1 max_fails=5;
}
incorrectly resulted in "invalid parameter "max_fails=5"" error.
For normal cached responses ngx_http_cache_send() sends last buffer and then
request finalized via ngx_http_finalize_request() call, i.e. everything is
ok.
But for stale responses (i.e. when upstream died, but we have something in
cache) the same ngx_http_cache_send() sends last buffer, but then in
ngx_http_upstream_finalize_request() another last buffer is send. This
causes duplicate final chunk to appear if chunked encoding is used (and
resulting problems with keepalive connections and so on).
Fix this by not sending in ngx_http_upstream_finalize_request()
another last buffer if we know response was from cache.
The special case in question leads to replies without body in
configuration like
location / { error_page 404 /zero; return 404; }
location /zero { return 204; }
while replies with empty body are expected per protocol specs.
Correct one will look like
if (status == NGX_HTTP_NO_CONTENT) {
rc = ngx_http_send_header(r);
if (rc == NGX_ERROR || r->header_only) {
return rc;
}
return ngx_http_send_special(r, NGX_HTTP_LAST);
}
though it looks like it's better to drop this special case at all.
Big POST (not fully preread) to a
location / {
return 202;
}
resulted in incorrect behaviour due to "return" code path not calling
ngx_http_discard_request_body(). The same applies to all "return" used
with 2xx/3xx codes except 201 and 204, and to all "return ... text" uses.
Fix is to add ngx_http_discard_request_body() call to ngx_http_send_response()
function where it looks appropriate. Discard body call from emtpy gif module
removed as it's now redundant.
Reported by Pyry Hakulinen, see
http://mailman.nginx.org/pipermail/nginx/2011-August/028503.html
Test case:
location / {
error_page 405 /nope;
return 405;
}
location /nope {
return 200;
}
This is expected to return 405 with empty body, but in 0.8.42+ will return
builtin 405 error page as well (though not counted in Content-Length, thus
breaking protocol).
Fix is to use status provided by rewrite script execution in case
it's less than NGX_HTTP_BAD_REQUEST even if r->error_status set. This
check is in line with one in ngx_http_script_return_code().
Note that this patch also changes behaviour for "return 302 ..." and
"rewrite ... redirect" used as error handler. E.g.
location / {
error_page 405 /redirect;
return 405;
}
location /redirect {
rewrite ^ http://example.com/;
}
will actually return redirect to "http://example.com/" instead of builtin 405
error page with meaningless Location header. This looks like correct change
and it's in line with what happens on e.g. directory redirects in error
handlers.
Replies with 201 code contain body, and we should clearly indicate it's
empty if it's empty. Before 0.8.32 chunked was explicitly disabled for
201 replies and as a result empty body was indicated by connection close
(not perfect, but worked). Since 0.8.32 chunked is enabled, and this
causes incorrect responses from dav module when HTTP/1.1 is used: with
"Transfer-Encoding: chunked" but no chunks at all.
Fix is to actually return empty body in special response handler instead
of abusing r->header_only flag.
See here for initial report:
http://mailman.nginx.org/pipermail/nginx-ru/2010-October/037535.html
This fixes crashes observed with some 3rd party balancer modules. Standard
balancer modules (round-robin and ip hash) explicitly set pc->connection
(aka u->peer.connection) to NULL and aren't affected.
If client closed connection in ngx_event_pipe_write_to_downstream(), buffers
in the "out" chain were lost. This caused cpu hog if all available buffers
were in the "out" chain. Fix is to call ngx_chain_update_chains() before
checking return code of output filter to avoid loosing buffers in the "out"
chain.
Note that this situation (all available buffers in the "out" chain) isn't
normal, it should be prevented by busy buffers limit. Though right now it
may happen with complex protocols like fastcgi. This should be addressed
separately.
The default value is 32 AIO simultaneous requests per worker. Previously
they were hardcoded to 1024, and it was too large, since Linux allocated
them early on io_setup(), but not on request itself. So with default value
of /proc/sys/fs/aio-max-nr equal to 65536 only 64 worker processes could
be run simultaneously. 32 AIO requests are enough for modern disks even if
server runs only 1 worker.
and "chunked_transfer_encoding" directives, to be in line with all
directives taking a boolean argument. Both flags will ensure that
a directive takes one argument.
syscall(2) uses usual libc convention, it returns -1 on error and
sets errno. Obsolete _syscall(2) returns negative value of error.
Thanks to Hagai Avrahami.
