Logging

Configure VerneMQ Logging.

Console Logging

Where should VerneMQ emit the default console log messages (which are typically at info severity):

log.console = off | file | console | both

VerneMQ defaults to log the console messages to a file, which can specified by:

log.console.file = /path/to/log/file

This option defaults to /var/log/vernemq/console.log for Ubuntu, Debian, RHEL and Docker installs.

The default console logging level info could be setting one of the following:

log.console.level = debug | info | warning | error

Error Logging

VerneMQ log error messages by default. One can change the default behaviour by setting:

log.error = on | off

VerneMQ defaults to log the error messages to a file, which can specified by:

log.error.file = /path/to/log/file

This option defaults to /var/log/vernemq/error.log for Ubuntu, Debian, RHEL and Docker installs.

Crash Logging

VerneMQ log crash messages by default. One can change the default behaviour by setting:

log.crash = on | off

VerneMQ defaults to log the crash messages to a file, which can specified by:

log.crash.file = /path/to/log/file

This option defaults to /var/log/vernemq/crash.log for Ubuntu, Debian, RHEL and Docker installs.

The maximum sizes in bytes of individual messages in the crash log defaults to 64KB but can be specified by:

log.crash.maximum_message_size = 64KB

VerneMQ rotate crash logs. By default, the crash log file is rotated at midnight or when the size exceeds 10MB. This behaviour can be changed by setting:

## Acceptable values:
##   - a byte size with units, e.g. 10GB
log.crash.size = 10MB

## For acceptable values see https://github.com/basho/lager/blob/master/README.md#internal-log-rotation
log.crash.rotation = $D0

The default number of rotated log files is 5 and can be set with the option:

log.crash.rotation.keep = 5

SysLog

VerneMQ supports logging to SysLog, enable it by setting:

log.syslog = on

Logging to SysLog is disabled by default.

The minimal SysLog logging level could be set to one of the following (defaults to all):

log.syslog.level = all | debug | info | warning | error

The SysLog message format defaults to rfc3164. Sending messages via TLS requires rfc5424:

log.syslog.format = rfc3164 | rfc5424

The SysLog facility used for local and remote messages defaults to daemon:

log.syslog.facility = daemon

Other acceptable facilities are kern, kernel, user, mail, auth, syslog, lpr, news, uucp, cron, authpriv, ftp, ntp, logaudit, logalert, clock and local0 to local7.

The application name included in SysLog messages can be set with:

log.syslog.app_name = vernemq

If unset, the node name is used.

Remote SysLog

Setting the remote SysLog server hostname or IP address enables delivery of SysLog messages to a remote host:

log.syslog.remote.host = syslog.example.com

The remote SysLog server port defaults to 514:

log.syslog.remote.port = 514

The transport used for remote SysLog delivery defaults to udp:

log.syslog.remote.protocol = udp | tcp | tls

When log.syslog.remote.protocol is set to tls, log.syslog.format must be rfc5424 and a CA certificate file must be provided to verify the remote server:

log.syslog.remote.tls.cafile = /path/to/cafile