Deleted value in dynamic config don't fallback

[amaury-d]

• Version: logstash-filter-translate-3.0.4
• Operating System: CentOS 7.2.1511
• Config File (if you have sensitive info, please remove it):

    translate {
      field => "application"
      dictionary_path => "/tech/logstash/conf.d/toolbox/config.yml"
      destination => "key"
      fallback => "log"
      refresh_interval => 30
  }

• Sample Data: config.yml:

  placeholder: placeholder
  foo: bar

• Steps to Reproduce:

1. Start logstash
2. Inject msg with application=foo, it translates to application=bar, no problem here
3. Then delete the line foo:bar from config
4. After dynamic refresh, application=foo keeps being translated to application=bar instead of fallback to application=log

[guyboertje]

This behaviour is has been the default since 10 Sep 2014. The dictionary is merged on reload so keys and values deleted on file will not be removed from the in-memory dictionary.

I suggest that, instead of deleting, you change the value to deleted-translation and then add a conditional block that replaces that value with your fallback.

[amaury-d]

For information, commit e33dc0a7c156d85ffde43174210dfaae1d5f19c5 added the option 'refresh_behaviour'