Error while using logstash just as a Gelf Router

[jordansissel]

(This issue was originally filed by @rikatz at elastic/logstash#1847)

---

Using logstash with input gelf, and output gelf to another server (in this case, a graylog2 server), the following error occurs:

Using milestone 2 input plugin 'gelf'. This plugin should be stable, but if you see strange behavior, please let us know! For more information on plugin milestones, see http://logstash.net/docs/1.4.2/plugin-milestones {:level=>:warn}
Using milestone 1 input plugin 'syslog'. This plugin should work, but would benefit from use by folks like you. Please let us know if you find bugs or have suggestions on how to improve this plugin. For more information on plugin milestones, see http://logstash.net/docs/1.4.2/plugin-milestones {:level=>:warn}
Using milestone 2 output plugin 'gelf'. This plugin should be stable, but if you see strange behavior, please let us know! For more information on plugin milestones, see http://logstash.net/docs/1.4.2/plugin-milestones {:level=>:warn}
NoMethodError: undefined method `join' for "_grokparsefailure":String
receive at /opt/programas/logstash/lib/logstash/outputs/gelf.rb:179
handle at /opt/programas/logstash/lib/logstash/outputs/base.rb:86
initialize at (eval):38
call at org/jruby/RubyProc.java:271
output at /opt/programas/logstash/lib/logstash/pipeline.rb:266
outputworker at /opt/programas/logstash/lib/logstash/pipeline.rb:225
start_outputs at /opt/programas/logstash/lib/logstash/pipeline.rb:152

Here is the logstash.conf file:

input {
gelf {
}
syslog {
port => 1514
}
}

output {
gelf {
host => "192.168.0.12"
}
}

Thanks in advice

[tboeghk]

Dug out this one: The problem still exists in the most recent version. This can be avoided by not shipping tags in the output part:

output {
  gelf {
    host => "192.168.0.12"
    ship_tags => false
  }
}

There seems to be a problem with parsing of tags received via the input plugin.