ngx_stream_log_module module (1.11.4) writes session logs
in the specified format.
log_format basic '$remote_addr [$time_local] ' '$protocol $status $bytes_sent $bytes_received ' '$session_time'; access_log /spool/logs/nginx-access.log basic buffer=32k;
Sets the path, format,
and configuration for a buffered log write.
Several logs can be specified on the same configuration level.
Logging to syslog
can be configured by specifying
syslog:” prefix in the first parameter.
The special value
off cancels all
access_log directives on the current level.
If either the
parameter is used, writes to log will be buffered.
The buffer size must not exceed the size of an atomic write to a disk file. For FreeBSD this size is unlimited.
When buffering is enabled, the data will be written to the file:
- if the next log line does not fit into the buffer;
if the buffered data is older than specified by the
- when a worker process is re-opening log files or is shutting down.
gzip parameter is used, then the buffered data will
be compressed before writing to the file.
The compression level can be set between 1 (fastest, less compression)
and 9 (slowest, best compression).
By default, the buffer size is equal to 64K bytes, and the compression level
is set to 1.
Since the data is compressed in atomic blocks, the log file can be decompressed
or read by “
zcat” at any time.
access_log /path/to/log.gz basic gzip flush=5m;
For gzip compression to work, nginx must be built with the zlib library.
The file path can contain variables, but such logs have some constraints:
- the user whose credentials are used by worker processes should have permissions to create files in a directory with such logs;
- buffered writes do not work;
the file is opened and closed for each log write.
However, since the descriptors of frequently used files can be stored
in a cache, writing to the old file
can continue during the time specified by the open_log_file_cache
if parameter enables conditional logging.
A session will not be logged if the
condition evaluates to “0”
or an empty string.
Specifies the log format, for example:
log_format proxy '$remote_addr [$time_local] ' '$protocol $status $bytes_sent $bytes_received ' '$session_time "$upstream_addr" ' '"$upstream_bytes_sent" "$upstream_bytes_received" "$upstream_connect_time"';
escape parameter (1.11.8) allows setting
default characters escaping
in variables, by default,
default escaping is used.
none parameter (1.13.10) disables escaping.
and other characters with values less than 32 or above 126
are escaped as “
If the variable value is not found,
a hyphen (“
-”) will be logged.
all characters not allowed
in JSON strings
will be escaped:
\” are escaped as
\"” and “
characters with values less than 32 are escaped as
Defines a cache that stores the file descriptors of frequently used logs whose names contain variables. The directive has the following parameters:
- sets the maximum number of descriptors in a cache; if the cache becomes full the least recently used (LRU) descriptors are closed
- sets the time after which the cached descriptor is closed if there were no access during this time; by default, 10 seconds
sets the minimum number of file uses during the time
defined by the
inactiveparameter to let the descriptor stay open in a cache; by default, 1
- sets the time after which it should be checked that the file still exists with the same name; by default, 60 seconds
- disables caching
open_log_file_cache max=1000 inactive=20s valid=1m min_uses=2;