Logstash is one of the most popular unified logging layer solutions. Currently, it is owned by Elastic, the company behind Elasticsearch. If you've heard of the ELK stack (now known as the Elastic Stack), Logstash is the "L" in the acronym.
Logstash was written in Ruby and then has been ported to JRuby. This unfortunately means that it is rather resource-intensive. For this reason, it is not advisable to run Logstash on each machine. Rather, it is meant to be used mainly as a log forwarder with lightweight Filebeat deployed to each machine and performing just the collection.