It is too difficult to analyze and investigate issue in case of distributed system failure or its low performance. Elasticsearch/Logstash/Kibana resolve this task and can be used instead of existing monitoring system or co existing with it. If your application consist of several components and deployed on more than one network nodes, then it can be useful for you. If you already have such system it can be interesting to know about Elasticsearch as NoSQL database, how to execute query to indexed data and how to create your own ES plugin.
Assistant Vice President, Deutsche Bank
I am working as Java developer about 9 years and prefer integration of existing open source project if it possible instead of invention of bicycle.