Top 4 Java Scalability Projects

Hazelcast

7 5,853 9.9 Java

Hazelcast is a unified real-time data platform combining stream processing with a fast data store, allowing customers to act instantly on data-in-motion for real-time insights.

Project mention: Does anyone know any good java implementations for distributed key-value store? | /r/ExperiencedDevs | 2023-06-08

You're probably looking for Hazelcast here. Note that it does much more than just a distributed k/v, but it will get you where you need to go.
AxonFramework

1 3,221 9.8 Java

Framework for Evolutionary Message-Driven Microservices on the JVM
InfluxDB

www.influxdata.com
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Power Real-Time Data Analytics at Scale. Get real-time insights from all types of time series data with InfluxDB. Ingest, query, and analyze billions of data points in real-time with unbounded cardinality.
coherence

10 412 9.7 Java

Oracle Coherence Community Edition (by oracle)
JedAIToolkit

1 200 3.5 Java

An open source, high scalability toolkit in Java for Entity Resolution.

NOTE: The open source projects on this list are ordered by number of github stars. The number of mentions indicates repo mentiontions in the last 12 Months or since we started tracking (Dec 2020). The latest post mention was on 2023-06-08.