Not able to redirect logs from CloudHub to Graylog (GELF)

SYMPTOM

CAUSE

SOLUTION

...
<dependency>
   <groupId>biz.paluch.logging</groupId>
   <artifactId>logstash-gelf</artifactId>
   <version>1.14.1</version>
</dependency>
...

<Configuration status="debug"
     packages="biz.paluch.logging.gelf.log4j2" >
...

<Appenders>
...
        <Gelf name="gelf" host="udp:xxx.xxx.xxx.xxx" port="12201" 
            version="1.0" extractStackTrace="true" filterStackTrace="true" 
            mdcProfiling="true" includeFullMdc="true" maximumMessageSize="8192"
            originHost="<api_name>"            
            additionalFieldTypes="fieldName1=String,fieldName2=Double,fieldName3=Long"
            ignoreExceptions="true">
            <Field name="timestamp" pattern="%d{dd MMM yyyy HH:mm:ss,SSS}" />
            <Field name="level" pattern="%level" />
            <Field name="simpleClassName" pattern="%C{1}" />
            <Field name="className" pattern="%C" />
            <Field name="server" pattern="%host" />
            <Field name="server.fqdn" pattern="%host{fqdn}" />
        </Gelf>
...
   </Appenders>
...
    <Loggers>
...
        <AsyncRoot level="INFO">
            <AppenderRef ref="file" />
            <AppenderRef ref="gelf"/>
        </AsyncRoot>
...
    </Loggers>