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InfoQ Homepage News Oracle Open Sources Coherence In-Memory Data Grid

Oracle Open Sources Coherence In-Memory Data Grid

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Oracle has released the core of their Coherence in-memory data grid (IMDG) product as free and open source software.

Named Coherence Community Edition, it has been released under the Open Source Initiative’s Universal Permissive License, Version 1.0, and is hosted on GitHub.

In its simplest form, an IMDG can be thought of as a Java Map that extends across multiple virtual machines and may optionally be persisted to disk. This simple mental model allows developers to quickly on-ramp to the technology, although the complexities of general distributed computing cannot be completely ignored (especially for advanced use cases).

The open source Coherence release provides a very familiar set of core IMDG features, including:

  • Parallel querying and aggregation
  • Fault-tolerant automatic sharding
  • Caching, querying, aggregation, transactions, in-place processing
  • Persistence
  • Eventing, messaging, and streaming

Similar to competing offerings in the IMDG space, Oracle has chosen a freemium model, with certain enterprise features being restricted to their Enterprise or Grid editions which are only available to paying customers.

Oracle clearly intends to bring Coherence back into the consciousness of Java / JVM developers working in microservice architectures. As part of this repositioning, they promise an extensive range of integrations with their other technology offerings, including Helidon, GraalVM, Oracle Database and Database Cloud.

To showcase the simplifications that they believe an in-memory data grid, such as Coherence, can bring to modern architectures, Oracle is including a microservices demo app, named Helidon Sock Shop.

Coherence was originally developed by Cameron Purdy and others at Tangosol, which was acquired by Oracle in 2007.

Developers can get a lot more information about the release at the Coherence Community website.

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Community comments

  • Wow! Well done!

    by Cameron Purdy,

    Your message is awaiting moderation. Thank you for participating in the discussion.

    I know that the Coherence team at Oracle has been working on this for a few years. It took a long time for them to convince the executives that this was a good strategic move, and then it took a long time for them to get everything approved that had to get approved to make it happen. So kudos to the Coherence team for following through on this very challenging project :-)

    Coherence is still a big business for Oracle, but hopefully this will open it up to a new set of people who have never had the "luxury" of giant enterprise Oracle software licensing. Obviously, Oracle is doing this because they hope to attract more of those enterprise accounts, but hopefully this will end up benefiting the open source Java community, the businesses using Java, and Oracle.

    There are still a few commercial features which I wish could have been opened up, like Elastic Data. But almost everything is there in the Community Edition. Even the custom IDE that we built (pre-Tangosol days) and used to create Coherence. I'll give $10 to the first person who figures out how it works :-D

  • Thank You InfoQ

    by Randy Stafford,

    Your message is awaiting moderation. Thank you for participating in the discussion.

    Thank you Ben Evans and InfoQ for the coverage! This was big initiative for the Coherence team at Oracle.

  • Re: Thank You InfoQ

    by Cameron Purdy,

    Your message is awaiting moderation. Thank you for participating in the discussion.

    It would be nice if it stayed up on the homepage for more than a few hours ...

  • Re: Thank You InfoQ

    by Daniel Bryant,

    Your message is awaiting moderation. Thank you for participating in the discussion.

    Sorry, Cameron -- we had a lot of news content published this week. Although this is good for traffic, it does mean that some things don't get to stay on the home page for long. We are exploring ways to change this in the future.

    Best wishes,


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