Manage logs

To specify a configuration file to change the logging behavior, add this line to the /etc/nova/nova.conf file . To change the logging level, such as DEBUG, INFO, WARNING, ERROR), use:

log-config=/etc/nova/logging.conf

The logging configuration file is an ini-style configuration file, which must contain a section called logger_nova, which controls the behavior of the logging facility in the nova-* services. For example:

[logger_nova]
level = INFO
handlers = stderr
qualname = nova

This example sets the debugging level to INFO (which less verbose than the default DEBUG setting).

You can configure OpenStack Compute services to send logging information to syslog. This is useful if you want to use rsyslog, which forwards the logs to a remote machine. You need to separately configure the Compute service (nova), the Identity service (keystone), the Image Service (glance), and, if you are using it, the Block Storage service (cinder) to send log messages to syslog. To do so, add the following lines to:

verbose = False
debug = False
use_syslog = True
syslog_log_facility = LOG_LOCAL0

In addition to enabling syslog, these settings also turn off more verbose output and debugging output from the log.

Note

Although the example above uses the same local facility for each service (LOG_LOCAL0, which corresponds to syslog facility LOCAL0), we recommend that you configure a separate local facility for each service, as this provides better isolation and more flexibility. For example, you may want to capture logging information at different severity levels for different services. syslog allows you to define up to seven local facilities, LOCAL0, LOCAL1, ..., LOCAL7. For more details, see the syslog documentation.

rsyslog is a useful tool for setting up a centralized log server across multiple machines. We briefly describe the configuration to set up an rsyslog server; a full treatment of rsyslog is beyond the scope of this document. We assume rsyslog has already been installed on your hosts (default for most Linux distributions).

This example provides a minimal configuration for /etc/rsyslog.conf on the log server host, which receives the log files:

# provides TCP syslog reception
$ModLoad imtcp
$InputTCPServerRun 1024

Add a filter rule to /etc/rsyslog.conf which looks for a host name. The example below uses compute-01 as an example of a compute host name:

:hostname, isequal, "compute-01" /mnt/rsyslog/logs/compute-01.log

On each compute host, create a file named /etc/rsyslog.d/60-nova.conf, with the following content:

# prevent debug from dnsmasq with the daemon.none parameter
*.*;auth,authpriv.none,daemon.none,local0.none -/var/log/syslog
# Specify a log level of ERROR
local0.error    @@172.20.1.43:1024

Once you have created this file, restart your rsyslog daemon. Error-level log messages on the compute hosts should now be sent to your log server.