ELK套件（ELK stack）是指ElasticSearch、Logstash和Kibana三件套。这三个软件可以组成一套日志分析和监控工具。
Elasticsearch是个开源分布式搜索引擎，它的特点有：分布式，零配置，自动发现，索引自动分片，索引副本机制，restful风格接口，多数据源，自动搜索负载等。
Logstash是一个完全开源的工具，他可以对你的日志进行收集、过滤，并将其存储供以后使用（如，搜索）。
Kibana 也是一个开源和免费的工具，它Kibana可以为 Logstash 和 ElasticSearch 提供的日志分析友好的 Web 界面，可以帮助您汇总、分析和搜索重要数据日志。
目前我们看到的 angularjs 版本 kibana 其实原名叫 elasticsearch-dashboard，但跟 Kibana2 作者是同一个人，换句话说，kibana 比 logstash 还早就进了 elasticsearch 名下。这个项目改名 Kibana 是在 2014 年 2 月，也被叫做 Kibana3。全新的设计一下子风靡 DevOps 界。随后其他社区纷纷借鉴，Graphite 目前最流行的 Grafana 界面就是由此而来，至今代码中还留存有十余处 kbn 字样。
2014 年 4 月，Kibana3 停止开发，ES 公司集中人力开始 Kibana4 的重构，在 2015 年初发布了使用 JRuby 做后端的 beta 版后，于 3 月正式推出使用 node.js 做后端的正式版。
What's New?
The latest release of Kibana is compatible with the latest version of Elasticsearch and features on-demand and scheduled PDF reports (via Watcher), greater customizability of labels and colors, and native authentication screen and session management with Shield (security). Learn more.
Seamless Integration with Elasticsearch
Architected to work with Elasticsearch, Kibana gives shape to any kind of data — structured and unstructured — indexed into Elasticsearch. It also benefits from Elasticsearch's powerful search and analytics capabilities.
Give Shape to Your Data
To better understand large volumes of data, easily create bar charts, line and scatter plots, histograms, pie charts, and maps.
Sophisticated Analytics
Leverage the power of Elasticsearch analytics capabilities to analyze your data intelligently, perform mathematical transformations, and slice and dice your data as you see fit.
Empower More Team Members
Visualizing data in a powerful interface empowers every line of business to make practical use of your data collection.
Flexible Interface, Easy to Share
Easily create, save, share, and embed your visualized data for quick and smart communication.
Easy Setup
Simple and friendly setup and startup. Kibana 4 ships with its own web server to help you get up and running quickly.
Visualize Data from Many Sources
Easily visualize data pushed into Elasticsearch from Logstash, ES-Hadoop, Beats, or third-party technologies like Apache Flume, Fluentd, and many others.
Simple Data Export
Easily export interesting bits of data to merge and meld with other data sets to quickly prototype new analyses and discover something new.
Visually Interact with Elasticsearch REST APIs
Sense is a visual console that provides auto-complete, auto-indentation, and syntax checking all through a Kibana plugin. Enhance the way that you interact with the Elasticsearch APIs
