Controlling logging
===================

Failover Manager writes and stores one log file per agent and one
startup log per agent in ``/var/log/<cluster_name>-4`` .

You can control the level of detail written to the agent log by
modifying the ``jgroups.loglevel`` and ``efm.loglevel`` parameters in
the :ref:`The cluster properties file <The cluster properties file>`  :

.. code:: ini

   #  Logging levels for JGroups and EFM.

   #  Valid values are: TRACE, DEBUG, INFO, WARN, ERROR

   #  Default value: INFO

   #  It is not necessary to increase these values unless debugging a

   #  specific issue. If nodes are not discovering each other at

   #  startup, increasing the jgroups level to DEBUG will show

   #  information about the TCP connection attempts that may help

   #  diagnose the connection failures.

   #  TRACE level logging should be used for diagnosing problems only.

   #  It is not supported for production use.

   jgroups.loglevel=INFO
   efm.loglevel=INFO

The logging facilities use the Java logging library and logging levels.
The log levels, in order from most logging output to least, are:

-  ``TRACE``

-  ``DEBUG``

-  ``INFO``

-  ``WARN``

-  ``ERROR``

For example, if you set the ``efm.loglevel`` parameter to ``WARN`` ,
Failover Manager only logs messages at the ``WARN`` level and above,
that is, ``WARN`` and ``ERROR`` .

By default, Failover Manager log files are rotated daily, compressed,
and stored for a week. You can modify the file rotation schedule by
changing settings in the log rotation file
(``/etc/logrotate.d/efm-4.<x>`` ). For more information about modifying
the log rotation schedule, consult the logrotate man page:

.. code:: shell

   $ man logrotate

Enabling syslog log file entries
--------------------------------

Failover Manager supports syslog logging. To implement syslog logging,
you must configure syslog to allow UDP or TCP connections.

To allow a connection to syslog, edit the ``/etc/rsyslog.conf`` file and
uncomment the protocol you want to use. Also make sure that the
``UDPServerRun`` or ``TCPServerRun`` entry associated with the protocol
includes the port number to which log entries are sent. For example, the
following configuration file entries enable UDP connections to port 514:

.. code:: shell

   #  Provides UDP syslog reception

   $ModLoad imudp
   $UDPServerRun 514

The following configuration file entries enable TCP connections to port
514:

.. code:: shell

   #  Provides TCP syslog reception

   $ModLoad imtcp
   $InputTCPServerRun 514

After modifying the syslog configuration file, restart the ``rsyslog``
service to enable the connections:

   ``systemctl restart rsyslog.service``

After modifying the ``rsyslog.conf`` file on the Failover Manager host,
modify the Failover Manager properties to enable logging. Use your
choice of editor to :ref:`modify the properties file <The cluster properties file>` 
``/etc/edb/efm-4.<x>/efm.properties.in`` , specifying the type of
logging that you want to implement:

.. code:: ini

   #  Which logging is enabled.

   file.log.enabled=true
   syslog.enabled=false

You must also :ref:`specify syslog details <The cluster properties file>`  for your system. Use the ``syslog.protocol``
parameter to specify the protocol type (UDP or TCP) and the
``syslog.port`` parameter to specify the listener port of the syslog
host. You can use the ``syslog.facility`` value as an identifier for the
process that created the entry. Use a value between ``LOCAL0`` and
``LOCAL7`` .

.. code:: ini

   #  Syslog information. The syslog service must be listening # on the

    port for the given protocol, which can be UDP or
   #  TCP. The facilities supported are LOCAL0 through LOCAL7.

   #  syslog.host=localhost

   syslog.port=514
   syslog.protocol=UDP
   syslog.facility=LOCAL1

For more information about syslog, see the syslog man page:

``man syslog``