NOTE: Work in progress and most def not working right now!

Logstash Dedupe Plugin

This is a plugin for Logstash which is designed to handle the de-duplication of events coming into a Logstash cluster in a HA architecture.

We achieve this by hashing the fields you wish to dedupe on and store those in a data store which we then check against. Should a match be found, we will tag it. You can then go on to drop {} it, or something similar.

Quickstart

For starters, this plugin uses redis as its data store so that you can have multiple logstash nodes sharing the same de-duplication information. You'll need to download redis and install it somewhere.

Next you need to install the plugin with /opt/logstash/bin/plugin -install logstash-filter-dedupe

Finally, add the filter in your logstash configuration:

filter {
  dedupe {
    keys => ["keys", "to", "hash"],
    host => "redis-ip",
    port => 6379,
    ttl  => 30
  }
}

The above settings are pretty simple, the only one to be wary of is ttl, this setting basically controls how long the duplication information is stored in redis before it is dropped, that's basically your "duplication window".

Any messages which are "duplicates" will have the "duplicate" tag added, you could then go on to drop that message with the drop filter:

filter {
  if "duplicate" in [tags] {
    drop {}
  }
}

NOTE: The README from this point down is primarily from the plugin template for a README.

Plugin Developement and Testing

You can use a docker container with all of the requirements pre installed to save you installing the development environment on your host.

1. Development

1.1 Starting the container

Simply type docker-compose run --rm devenv and you'll be entered into the container.

1.2 Running tests

Once you've done #1 above, you can run your tests with jruby -S bundle exec rspec

2. Running your unpublished Plugin in Logstash

2.1 Run in a local Logstash clone

• Edit Logstash Gemfile and add the local plugin path, for example:

gem "logstash-filter-dedupe", :path => "/your/local/logstash-filter-dedupe"

• Install plugin

bin/plugin install --no-verify

• Run Logstash with your plugin

bin/logstash -e 'filter {dedupe {}}'

At this point any modifications to the plugin code will be applied to this local Logstash setup. After modifying the plugin, simply rerun Logstash.

2.2 Run in an installed Logstash

You can use the same 2.1 method to run your plugin in an installed Logstash by editing its Gemfile and pointing the :path to your local plugin development directory or you can build the gem and install it using:

• Build your plugin gem

gem build logstash-filter-dedupe.gemspec

• Install the plugin from the Logstash home

bin/plugin install /your/local/plugin/logstash-filter-dedupe.gem

• Start Logstash and proceed to test the plugin

Contributing

All contributions are welcome: ideas, patches, documentation, bug reports, complaints, and even something you drew up on a napkin.

Programming is not a required skill. Whatever you've seen about open source and maintainers or community members saying "send patches or die" - you will not see that here.

It is more important to the community that you are able to contribute.

For more information about contributing, see the CONTRIBUTING file.