In-Memory Computing Platform


Hazelcast offers a number of different distributed data structures under a simple API, so that users don't need to handle the complexity of distributed data systems by themselves.


  • Full-featured IMDG
  • JCache Provider
  • Apache 2 License
  • Small JAR with Minimal Dependencies
  • Embedded or Client Server
  • API with Multiple Language Clients: Java, C, C#, Python, Go, JavaScript (Node.js)

Sample of supported data structures

  • Map, Replicated Map, Multi Map
  • Set, List, Queue
  • RingBuffer, HyperLogLog
  • AtomicLong, AtomicReference, FencedLock
  • etc.


  • JCache provider
  • Hibernate 2nd-level cache
  • Spring Cache
  • Spring Sessions
  • Tomcat/Jetty session replication etc.

Because of its main cache use-case, Hazelcast is Available regarding the CAP theorem. There's also a dedicated Consistent subsystem.

Hazelcast Jet

Hazelcast Jet is an application embeddable, stream processing engine designed for fast processing of big data sets. The Hazelcast Jet architecture is high performance and low-latency-driven, based on a parallel, streaming core engine that enables data-intensive applications to operate at near real-time speeds. Jet is used to develop stream or batch processing applications using directed acyclic graph (DAG) at its core.

We offer proposals on both Hazelcast IMDG and Hazelcast Jet

lightbulb_outline View ideas list


  • java
  • distributed systems


comment IRC Channel
email Mailing list

Hazelcast 2020 Projects

  • Anmol Chaddha
    Improved Telemetry of Hazelcast
    The telemetry (or Phone Home) is a hazelcast feature that lets us gather usage information about how the community uses the Hazelcast product....
  • Mohamed Mandouh
    RocksDB as a state backend for Jet
    The project aims to use RocksDB persistent storage as a state back-end for Jet batch processors that require large state and don't need cutting-edge...