Apache Druid
A high performance real-time analytics database
...As such, Druid is often used to power UIs where an interactive, consistent user experience is desired. Druid streams data from message buses such as Kafka, and Amazon Kinesis, and batch load files from data lakes such as HDFS, and Amazon S3. Druid supports most popular file formats for structured and semi-structured data. Druid has been benchmarked to greatly outperform legacy solutions. Druid combines novel storage ideas, indexing structures, and both exact and approximate queries to return most results in under a second. Druid unlocks new types of queries and workflows for clickstream, APM, supply chain, network telemetry, digital marketing, risk/fraud, and many other types of data. ...