For those using logstash-forwarder but also using Hortonworks stack (HDP and HDF)
I have baked an experimental listener that allows Hortonworks Dataflow (a.k.a. Apache NiFi) to accept connections from logstash-forwarder agents.
The rationale for that is to allow for a drop in replacement for simpler pipelines (e.g. logstash-forwarder -> pipeline -> HDFS / Kafka / whatever) while providing stronger delivery guarantees than Logstash currently offers (NiFi's documentation provides insight over its data provenance and guarantees).
The code is still experimental and I would strongly appreciate if people could assist by testing it against a more diverse set of environments.