Netflix seems to use Druid and did a very good feedback of this tech at Big Data 2017.
Druid is a streaming analytics data store that is ideal for powering user-facing data applications. Druid is often used to explore events immediately after they occur and to combine real-time results with historical events. Druid can ingest data at a rate of millions of events per second and is often paired with a message bus such as Kafka for high availability and flexibility.
Performance looks very good and we have to explore deeper this technology.