Hazelcast IMDG (In Memory Data Grid) is a Java-based NoSQL open-source distributed in-memory data store and computation platform. It spreads and replicates data across a cluster of machines, therefore ensuring high availability, fault-tolerance and painless horizontal scalability. Hazelcast provides APIs for many of the most commonly used programming languages, including Java, C#, Python, Go and others. It can also be deployed on several different cloud environments, thanks to its multiple discovery plugins. Hazelcast's most common use cases include database caching, in-memory data computing and in-memory messaging.
Hazelcast is both the name of the product and the company that created it. The start-up was founded in 2008 by Talip Ozturk and Fuad Malikov. The first open-source implementation of Hazelcast was released at the beginning of 2009. Several updated versions have been made public since then, the latest one dating from February 4, 2020.
Hazelcast is a fully in-memory data store. It was not initially build to persist. However, the current Entreprise version of the product implements the "Hot Restart Persistence" feature, which provides faster restarts by storing cluster member states on disk.
Hazelcast's main data storage model is a partitioned and queryable in-memory key-value store. However, Hazelcast also supports a variety of additional distributed data structures derived from the Java programming language, such as Queue, Set, MultiMap, Topic and others.