Log4j input with empty members

I'm trying to use Logstash to index my log files created by log4j. I'm using the following versions:

  • Logstash: 2.1.1
  • ES: 2.1.0
  • log4j: 1.2.17

I followed the recommendation found at http://stackoverflow.com/a/26227002 and use the SocketAppender in log4j configuration (and there are many more questions/articles on the net recommending the log4j input in Logstash and the SocketAppender in log4j)

The SocketAppender is defined as following:

<appender name="socket" class="org.apache.log4j.net.SocketAppender">
    <param name="RemoteHost" value="localhost" />
    <param name="Port" value="4560" />
    <param name="LocationInfo" value="true"/>
    <layout class="org.apache.log4j.PatternLayout">
        <param name="ConversionPattern" value="[%d{ISO8601}][%-5p][%-25c] %m%n" />

I tried with the PatternLayout as described here https://www.elastic.co/blog/logging-elasticsearch-events-with-logstash-and-elasticsearch (although the pattern will be ignored according to http://stackoverflow.com/questions/11270504/how-to-use-pattern-layout-with-socketappender )

My pipe is defined as following:

input {
    log4j {
        mode => server
        host => ""
        port => "4560"
        type => "ex"
output {
    stdout { codec => rubydebug }
    elasticsearch { index => exlogs }

The events are indexed, and the output on stdout looks like the following:

        "message" => "dummy error",
       "@version" => "1",
     "@timestamp" => "2015-12-15T09:00:43.978Z",
      "timestamp" => 1450170043978,
           "path" => "com.ex.monitoring.jmxclient.JmxReader",
       "priority" => "ERROR",
    "logger_name" => "com.ex.monitoring.jmxclient.JmxReader",
         "thread" => "hugo",
          "class" => "?",
           "file" => "?:?",
         "method" => "?",
           "host" => "",
           "type" => "ex"

I'm wondering why "class", "file", "method" are empty all the time? Am I doing anything wrong?

These information are to be considered debug information because they are costly to produce,
and are only written to the appender when it is configured to do so with

<param name="LocationInfo" value="true" />

On the other hand I think the input should not write "garbage" that correspond to "not available", I have raise an issue about this in https://github.com/logstash-plugins/logstash-input-log4j/issues/25

Thanks for the reply.

I have this parameter configured in the appender (see the log4j configuration in my initial post). Any idea what I might be missing?

Oups, sorry to have overlooked that.
I used your appender config in a quick test, and the correct info is sent to Logstash. So i'm rather clueless.

Do you have any additional custom configuration for Log4j such as a custom implementation of Logger ? that could be a reason...

Or is there another socket appender configured without the LocationInfo enabled ??

Oh, it's b/c I use an async appender and this one is sending to the socket, now I directly send to socket w/o the async appender and I'm getting it.

Thanks for your support.