Hazelcast - Clustering and highly scalable data distribution platform for Java
Apache Spark - Apache Spark is an engine for big data processing, with built-in modules for streaming, SQL, machine learning and graph processing.
Apache Storm - Apache Storm is a free and open source distributed realtime computation system.
logstash - logstash is a tool for managing events and logs.
Redis - Redis is an open source in-memory data structure project implementing a distributed, in-memory key-value database with optional durability.
Confluent - Confluent offers a real-time data platform built around Apache Kafka.