Ready for Testing: Neo4j Enterprise Edition 4.0 Milestone Release 2

Today I am proud to announce – on behalf of the Neo4j team – that we have just published Neo4j Enterprise Edition 4.0 Milestone Release 2, now ready for testing by the Neo4j community.

Introducing Our First Neo4j 4.0 Milestone Release

Neo4j Enterprise Edition 4.0 Milestone Release 2 (or MR2) is a pre-alpha version that contains some of the upcoming features of the next planned release, giving you the opportunity to try them out and see if they benefit your project or application.

It is important to consider that MR2 is not ready for production. Considering the early stage of this release, some issues are expected, and we strongly advise you to use data that is suitable for testing purposes.

Why Milestone Release 2? Prior to today’s release, we created Milestone Release 1 as an internal release for a first pass at shaking out bugs and issues. Thus, this release is Milestone Release 2.

Editions and Source Code Availability

This MR2 preview uses the Enterprise Edition, i.e. it’s a superset release containing some features that will be available in both the Community and Enterprise Editions of Neo4j 4.0, in addition to some features that will be available only in the Enterprise Edition. (In the MR2 documentation we make clear which features a user may expect in the two future editions.)

Since this version is not officially part of our release cycle, we have prioritized the availability of the largest number of features to experiment with. Consequently, MR2 comes only in the form of pre-packaged binaries and is commercially licensed under the Neo4j Pre-Release Agreement, which means that it is freely available to all users but only for a limited period.

Community and Enterprise Editions will be publicly available with the first Alpha version of Neo4j, then we will make the source code available for Community Edition, as well as the binaries and packages available for the most common platforms we support.

MR2 is being made available via Neo4j Desktop in the same version of Neo4j Enterprise Edition that will be freely available upon GA.

What’s in Neo4j Enterprise Edition 4.0 Milestone Release 2?

Let’s take a quick overview of what you will be able to test out. For more details, refer to the official documentation of MR2.

The 4.0 release is the most feature-rich version of the Neo4j Graph Database to date. This is what you can already try in MR2:



Reactive Drivers So far available only for Java and JavaScript, the new drivers provide Reactive Streams capabilities.
Back Pressure & Flow Control Client drivers benefit from server-side flow control, result set may be temporarily kept in the server and retrieved in chunks, synchronously or asynchronously.
Support for multiple databases* Database administrators can now create new databases with administrative commands while the DBMS is online and users can connect to multiple databases at the same time.
Fine-Grained Security with a Schema-Based Model* We have created a new security model based on roles and privileges associated to graph entities – using role-based access control – that allows administrators to control users’ operations at the finest level: for read or write operations, for entire graphs, for graph elements (i.e., nodes and relationships) and for properties in graph elements.
Role & User Management* Schema-based security is defined by security roles and the granting of roles to users. We made significant improvements to create special roles, to use multiple roles for single users and also to improve the control of users in terms of password management and account activation.
System Database A system database used internally by the DBMS to store security and other system metadata. This replaces the password file used in the 2.x and 3.x series.
neo4j:// scheme Applications can now connect seamlessly to standalone and to Causal Cluster DBMS using the new neo4j:// scheme. The scheme is equivalent to the combination of the Bolt protocol and the client routing available for Causal Clustering, but it is now available also in standalone installations.
New Spring Boot Starter A new starter is now available to configure the Neo4j Java Driver within Spring Boot.
SDN/RX A new, experimental version of the next generation of the Spring Data module for Neo4j is now available for testing. It is also based on Reactive Streams.
Index Population Algorithm We have implemented a new index population algorithm that is significantly faster at initial population of native indexes than in the Neo4j 3.x series.
Index Key Size The maximum index key size has been increased to ~8KB for the Native Index Provider (GB+Tree).
Improved Space Reclaim The ID store has been re-engineered to remove corner cases where space reclaim after the deletion of graph elements was suboptimal. The new approach benefits both standalone and clustered systems, and is fully functional in both Community and Enterprise editions.
*Enterprise Edition
All these features are immediately available for standalone and clustered installations of Neo4j.

How Can I Try MR2?

MR2 is first and foremost available via Neo4j Desktop. You can install a Desktop Canary version with MR2 built in. Note: this is a distinct version of Neo4j Desktop that can be installed alongside the current GA version, which includes updates to support Neo4j 4.0.

MR2 is also available in the Neo4j Download Center. You can choose your version of the server to install on Linux, MacOS or Windows systems.

Alternatively, you can install MR2 as a Neo4j server from the yum and Debian testing repositories of Neo4j. The MR2 documentation explains how to install these packages.

We Need Your Feedback!

This is your chance to try out the new, exciting features of the most widely used graph database on the planet. More importantly, please give us your comments, feedback and suggestions on how we can improve the latest features and what we could add in future versions.

If you have great new ideas or you spot something that is not optimal for your use case, tell us up front: It’s not too late for us to review the current work and improve it.

In short, you can contribute in many ways:

    • If you are a customer: Submit issues or ask for help using the regular channels, more specifically the customer support portal. This is particularly useful if you intend to discuss the use of MR2 in particularly sensitive use cases.
    • For everybody: Submit issues through our GitHub public repository – tags for MR2 will come soon. If you have ideas to share, comments or more generic questions, we encourage you to use our Neo4j Community portal. A new 4.0 category is now available. These are the best ways to share your thoughts and perspectives and to engage everybody in the improvement of Neo4j 4.0!
One last important note: Some of the features and the exposed interface – in terms of commands, syntax, API and procedures – are subject to change. What you see in MR2 may not be exactly what you will find in the final GA version of the product.


And now we pass the keyboard over to you.

It’s your turn to download and test out the exciting new Milestone Release 2, provide feedback and continue to make history in the world of connected data and graph database technology!

With real joy and pride, on behalf of the whole Neo4j team,


Read to take Neo4j Enterprise Edition 4.0 for a test drive?
Visit the Pre-Release section of our download center to get access today.

Test Neo4j Enterprise Edition 4.0