Druid is a column-oriented, open-source, distributed data store written in Java. Druid is designed to quickly ingest massive quantities of event data, and provide low-latency queries on top of the data. The name Druid comes from the shapeshifting Druid class in many role-playing games, to reflect the fact that the architecture of the system can shift to solve different types of data problems.
Druid is commonly used in business intelligence/OLAP applications to analyze high volumes of real-time and historical data. Druid is used in production by technology companies such as Alibaba, Airbnb, Cisco, eBay, Lyft, Netflix, PayPal, Pinterest, Twitter, Walmart, Wikimedia Foundation and Yahoo.