Configure logging
editConfigure logging
editThe logging
section of the heartbeat.yml
config file contains options
for configuring the logging output.
The logging system can write logs to the syslog or rotate log files. If logging
is not explicitly configured the file output is used.
logging.level: info logging.to_files: true logging.files: path: /var/log/heartbeat name: heartbeat keepfiles: 7 permissions: 0644
In addition to setting logging options in the config file, you can modify the logging output configuration from the command line. See Command reference.
Configuration options
editYou can specify the following options in the logging
section of the
heartbeat.yml
config file:
logging.to_syslog
editWhen true, writes all logging output to the syslog.
This option is not supported on Windows.
logging.to_eventlog
editWhen true, writes all logging output to the Windows Event Log.
logging.to_files
editWhen true, writes all logging output to files. The log files are automatically rotated when the log file size limit is reached.
Heartbeat only creates a log file if there is logging output. For
example, if you set the log level
to error
and there are no
errors, there will be no log file in the directory specified for logs.
logging.level
editMinimum log level. One of debug
, info
, warning
, or error
. The default
log level is info
.
-
debug
-
Logs debug messages, including a detailed printout of all events
flushed. Also logs informational messages, warnings, errors, and
critical errors. When the log level is
debug
, you can specify a list ofselectors
to display debug messages for specific components. If no selectors are specified, the*
selector is used to display debug messages for all components. -
info
- Logs informational messages, including the number of events that are published. Also logs any warnings, errors, or critical errors.
-
warning
- Logs warnings, errors, and critical errors.
-
error
- Logs errors and critical errors.
logging.selectors
editThe list of debugging-only selector tags used by different Heartbeat components.
Use *
to enable debug output for all components. For example add publish
to display
all the debug messages related to event publishing.
When starting heartbeat, selectors can be overwritten using the -d
command
line option (-d
also sets the debug log level).
logging.metrics.enabled
editIf enabled, Heartbeat periodically logs its internal metrics that have changed in the last period. For each metric that changed, the delta from the value at the beginning of the period is logged. Also, the total values for all non-zero internal metrics are logged on shutdown. The default is true.
Here is an example log line:
2017-12-17T19:17:42.667-0500 INFO [metrics] log/log.go:110 Non-zero metrics in the last 30s: beat.info.uptime.ms=30004 beat.memstats.gc_next=5046416
Note that we currently offer no backwards compatible guarantees for the internal metrics and for this reason they are also not documented.
logging.metrics.period
editThe period after which to log the internal metrics. The default is 30s.
logging.files.path
editThe directory that log files are written to. The default is the logs path. See the Directory layout section for details.
logging.files.name
editThe name of the file that logs are written to. The default is heartbeat.
logging.files.rotateeverybytes
editThe maximum size of a log file. If the limit is reached, a new log file is generated. The default size limit is 10485760 (10 MB).
logging.files.keepfiles
editThe number of most recent rotated log files to keep on disk. Older files are
deleted during log rotation. The default value is 7. The keepfiles
options has
to be in the range of 2 to 1024 files.
logging.files.permissions
editThe permissions mask to apply when rotating log files. The default value is
0600. The permissions
option must be a valid Unix-style file permissions mask
expressed in octal notation. In Go, numbers in octal notation must start with
0.
Examples:
- 0644: give read and write access to the file owner, and read access to all others.
- 0600: give read and write access to the file owner, and no access to all others.
- 0664: give read and write access to the file owner and members of the group associated with the file, as well as read access to all other users.
logging.files.interval
editEnable log file rotation on time intervals in addition to size-based rotation. Intervals must be at least 1s. Values of 1m, 1h, 24h, 7*24h, 30*24h, and 365*24h are boundary-aligned with minutes, hours, days, weeks, months, and years as reported by the local system clock. All other intervals are calculated from the unix epoch. Defaults to disabled.
logging.json
editWhen true, logs messages in JSON format. The default is false.
Logging format
editThe logging format is generally the same for each logging output. The one exception is with the syslog output where the timestamp is not included in the message because syslog adds its own timestamp.
Each log message consists of the following parts:
- Timestamp in ISO8601 format
- Level
- Logger name contained in brackets (Optional)
- File name and line number of the caller
- Message
- Structured data encoded in JSON (Optional)
Below are some samples:
2017-12-17T18:54:16.241-0500 INFO logp/core_test.go:13 unnamed global logger
2017-12-17T18:54:16.242-0500 INFO [example] logp/core_test.go:16 some message
2017-12-17T18:54:16.242-0500 INFO [example] logp/core_test.go:19 some message {"x": 1}