symfony/src/Symfony/Bundle/MonologBundle/Resources/config/monolog.xml

<?xml version="1.0" ?>

<container xmlns="http://symfony.com/schema/dic/services"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xsi:schemaLocation="http://symfony.com/schema/dic/services http://symfony.com/schema/dic/services/services-1.0.xsd">

    <parameters>
        <parameter key="monolog.logger.class">Symfony\Bundle\MonologBundle\Logger\Logger</parameter>
        <parameter key="monolog.handler.stream.class">Monolog\Handler\StreamHandler</parameter>
        <parameter key="monolog.handler.fingers_crossed.class">Monolog\Handler\FingersCrossedHandler</parameter>
        <parameter key="monolog.handler.buffer.class">Monolog\Handler\BufferHandler</parameter>
        <parameter key="monolog.handler.rotating_file.class">Monolog\Handler\RotatingFileHandler</parameter>
        <parameter key="monolog.handler.syslog.class">Monolog\Handler\SyslogHandler</parameter>
        <parameter key="monolog.handler.null.class">Monolog\Handler\NullHandler</parameter>
        <parameter key="monolog.handler.test.class">Monolog\Handler\TestHandler</parameter>
        <parameter key="monolog.handler.firephp.class">Symfony\Bundle\MonologBundle\Logger\FirePHPHandler</parameter>
        <parameter key="monolog.handler.debug.class">Symfony\Bundle\MonologBundle\Logger\DebugHandler</parameter>
    </parameters>

    <services>
        <service id="monolog.logger" parent="monolog.logger_prototype" public="false">
            <argument index="0">app</argument>
        </service>
        <service id="logger" alias="monolog.logger" />
        <service id="monolog.logger_prototype" class="%monolog.logger.class%" abstract="true">
            <argument /><!-- Channel -->
        </service>
    </services>
</container>