5.4.2.3 Error Logging to the System Log
It is possible to have mysqld write the error log to the system log (the Event Log on Windows, and syslog
on Unix and Unix-like systems). To do so, use these system variables:
log_syslog
: Enable this variable to send the error log to the system log. (On Windows,log_syslog
is enabled by default.)If
log_syslog
is enabled, the following system variables can also be used for finer control.log_syslog_facility
: The default facility forsyslog
messages isdaemon
. Set this variable to specify a different facility.log_syslog_include_pid
: Whether to include the server process ID in each line ofsyslog
output.log_syslog_tag
: This variable defines a tag to add to the server identifier (mysqld
) insyslog
messages. If defined, the tag is appended to the identifier with a leading hyphen.
Error logging to the system log may require additional system configuration. Consult the system log documentation for your platform.
On Unix and Unix-like systems, control of output to syslog
is also available using mysqld_safe, which can capture server error output and pass it to syslog
.
Using mysqld_safe for syslog
error logging is deprecated; you should use the server system variables instead.
mysqld_safe has three error-logging options, --syslog
, --skip-syslog
, and --log-error
. The default with no logging options or with --skip-syslog
is to use the default log file. To explicitly specify use of an error log file, specify --log-error=
to mysqld_safe, which then arranges for mysqld to write messages to a log file. To use file_name
syslog
, specify the --syslog
option. For syslog
output, a tag can be specified with --syslog-tag=
; this is appended to the tag_val
mysqld
server identifier with a leading hyphen.