Журналирование
Each Tarantool instance logs important events to its own log file <instance-name>.log
.
For instances started with tt, the log location is defined by
the log_dir
parameter in the tt configuration.
By default, it’s /var/log/tarantool
in the tt
system mode,
and the var/log
subdirectory of the tt
working directory in the local mode.
In the specified location, tt
creates separate directories for each instance’s logs.
To check how logging works, write something to the log using the log module:
$ tt connect my_app
• Connecting to the instance...
• Connected to /var/run/tarantool/my_app.control
/var/run/tarantool/my_app.control> require('log').info("Hello for the manual readers")
Затем проверим содержимое журнала:
$ tail /var/log/tarantool/my_app.log
2023-09-12 18:13:00.396 [67173] main/111/guard of feedback_daemon/box.feedback_daemon V> metrics_collector restarted
2023-09-12 18:13:00.396 [67173] main/103/-/box.feedback_daemon V> feedback_daemon started
2023-09-12 18:13:00.396 [67173] main/103/- D> memtx_tuple_new_raw_impl(14) = 0x1090077b4
2023-09-12 18:13:00.396 [67173] main/103/- D> memtx_tuple_new_raw_impl(26) = 0x1090077ec
2023-09-12 18:13:00.396 [67173] main/103/- D> memtx_tuple_new_raw_impl(39) = 0x109007824
2023-09-12 18:13:00.396 [67173] main/103/- D> memtx_tuple_new_raw_impl(24) = 0x10900785c
2023-09-12 18:13:00.396 [67173] main/103/- D> memtx_tuple_new_raw_impl(39) = 0x109007894
2023-09-12 18:13:00.396 [67173] main/106/checkpoint_daemon I> scheduled next checkpoint for Tue Sep 12 19:44:34 2023
2023-09-12 18:13:00.396 [67173] main I> entering the event loop
2023-09-12 18:13:11.656 [67173] main/114/console/unix/:/tarantool I> Hello for the manual readers
When logging to a file, the system administrator must ensure
logs are rotated timely and do not take up all the available disk space.
The recommended way to prevent log files from growing infinitely is using an external
log rotation program, for example, logrotate
, which is pre-installed on most
mainstream Linux distributions.
A Tarantool log rotation configuration for logrotate
can look like this:
/var/log/tarantool/*.log {
daily
size 512k
missingok
rotate 10
compress
delaycompress
create 0640 tarantool adm
postrotate
tt -c <tt_config_file> logrotate
endscript
}
In this configuration, tt logrotate is called after each log
rotation to reopen the instance log files after they are moved by the logrotate
program.
There is also the built-in function log.rotate(), which you can call on an instance to reopen its log file after rotation.
To learn about log rotation in the deprecated tarantoolctl
utility,
check its documentation.
Tarantool can write its logs to a log file, to syslog
, or to a specified program
through a pipe.
File is the default log format for tt
. To send logs to a pipe or syslog
,
specify the box.cfg.log parameter, for example:
box.cfg{log = '| cronolog tarantool.log'}
-- or
box.cfg{log = 'syslog:identity=tarantool,facility=user'}
In such configurations, log rotation is usually handled by the external program used for logging.