Example of usage:
error_log memory:16m debug;
This allows to configure debug logging with minimum impact on performance.
It's especially useful when rare crashes are experienced under high load.
The log can be extracted from a coredump using the following gdb script:
set $log = ngx_cycle->log
while $log->writer != ngx_log_memory_writer
set $log = $log->next
end
set $buf = (ngx_log_memory_buf_t *) $log->wdata
dump binary memory debug_log.txt $buf->start $buf->end
The code tried to use suffixes for "long" and "long long" types, but
it never worked as intended due to the bug in the shell code. Also,
the max value for any 64-bit type other than "long long" on platforms
with 32-bit "long" would be incorrect if the bug was fixed.
So instead of fixing the bug in the shell code, always use the "int"
constant for 32-bit types, and "long long" constant for 64-bit types.
Keeping the ready flag in this case might results in missing notification of
broken connection until nginx tried to use it again.
While there, stale comment about stale event was removed since this function
is also can be called directly.
The code that calls sendfile() was cut into a separate function.
This simplifies EINTR processing, yet is needed for the following
changes that add threads support.
In case of filter finalization, r->upstream might be changed during
the ngx_event_pipe() call. Added an argument to preserve it while
calling the ngx_http_upstream_process_request() function.
A request may be already finalized when ngx_http_upstream_finalize_request()
is called, due to filter finalization: after filter finalization upstream
can be finalized via ngx_http_upstream_cleanup(), either from
ngx_http_terminate_request(), or because a new request was initiated
to an upstream. Then the upstream code will see an error returned from
the filter chain and will call the ngx_http_upstream_finalize_request()
function again.
To prevent corruption of various upstream data in this situation, make sure
to do nothing but merely call ngx_http_finalize_request().
Prodded by Yichun Zhang, for details see the thread at
http://nginx.org/pipermail/nginx-devel/2015-February/006539.html.
Previously, connection hung after calling ngx_http_ssl_handshake() with
rev->ready set and no bytes in socket to read. It's possible in at least the
following cases:
- when processing a connection with expired TCP_DEFER_ACCEPT on Linux
- after parsing PROXY protocol header if it arrived in a separate TCP packet
Thanks to James Hamlin.
When replacing a stale cache entry, its last_modified and etag could be
inherited from the old entry if the response code is not 200 or 206. Moreover,
etag could be inherited with any response code if it's missing in the new
response. As a result, the cache entry is left with invalid last_modified or
etag which could lead to broken revalidation.
For example, when a file is deleted from backend, its last_modified is copied to
the new 404 cache entry and is used later for revalidation. Once the old file
appears again with its original timestamp, revalidation succeeds and the cached
404 response is sent to client instead of the file.
The problem appeared with etags in 44b9ab7752e3 (1.7.3) and affected
last_modified in 1573fc7875fa (1.7.9).
Repeatedly calling ngx_http_upstream_add_chash_point() to create
the points array in sorted order, is O(n^2) to the total weight.
This can cause nginx startup and reconfigure to be substantially
delayed. For example, when total weight is 1000, startup takes
5s on a modern laptop.
Replace this with a linear insertion followed by QuickSort and
duplicates removal. Startup for total weight of 1000 reduces to 40ms.
Based on a patch by Wai Keen Woon.
Previously, the Auth-SSL-Verify header with the "NONE" value was always passed
to the auth_http script if verification of client certificates is disabled.
The "ssl_verify_client", "ssl_verify_depth", "ssl_client_certificate",
"ssl_trusted_certificate", and "ssl_crl" directives introduced to control
SSL client certificate verification in mail proxy module.
If there is a certificate, detail of the certificate are passed to
the auth_http script configured via Auth-SSL-Verify, Auth-SSL-Subject,
Auth-SSL-Issuer, Auth-SSL-Serial, Auth-SSL-Fingerprint headers. If
the auth_http_pass_client_cert directive is set, client certificate
in PEM format will be passed in the Auth-SSL-Cert header (urlencoded).
If there is no required certificate provided during an SSL handshake
or certificate verification fails then a protocol-specific error is
returned after the SSL handshake and the connection is closed.
Based on previous work by Sven Peter, Franck Levionnois and Filipe Da Silva.
Initial size as calculated from the number of elements may be bigger
than max_size. If this happens, make sure to set size to max_size.
Reported by Chris West.
