Server extensions

Server extensions allow new surfaces to be created in the REST API. Use them if you want more fine-grained control over your application's interactions with Neo4j than Cypher provides.

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If you want to add Neo4j or community extension, it will most probably be a library with stored procedures and you will need to add it as a new stored procedure. More on stored procedures here.

To know more about how to write and test your extensions please read the Neo4j unmanaged server extensions documentation.

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Please be careful with server extensions. You will be able to deploy JAX-RS classes to the server, and it’s easy to consume lots of heap space and degrade performance.

We highly encourage you to test your server extensions in staging environments before uploading them into production.

Preparing your server extension

Once you have written or downloaded an extension, you will need to pack it in a compressed file. As part of the compressed file you’ll need to add a neo4j-server.properties file, where you’ll put all the needed configuration for your extension, such as where Neo4j will look for it.

dbms.unmanaged_extension_classes=com.graphaware.server=/graphaware

Further considerations

Please take the following considerations into account while preparing your server extension to be uploaded:d

• Supported formats are zip, tar, cpio, gz, bz2 and xz.
• There is a size limit of 100MB.
• A file can contain multiple .jar files in the top-level directory.
• Only files with jar format or neo4j-server.properties are extracted, the rest will be ignored. *
• If a neo4j-server.properties file is found, its content is added to the neo4j-server.properties of the Neo4j process.
• neo4j-server.properties can contain $PLUGIN_ROOT, which will be replaced with the path of the plug-in. This can be used to reference files in the archive.

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Note

Graphaware extensions use a neo4j.properties file instead of a neo4j-server.properties file for their configuration. GrapheneDB takes care of this for you automatically. Read more in Graphaware extensions section.

Adding server extensions

Follow these instructions to add a new server extension to your database:

1. Navigate to the Extensions tab of your database dashboard, and click on the New server extension button from the dropdown menu New extension.
2. Name your extension in order to be able to identify it afterwards.
3. Select the compressed file from your local path and click.
4. Do not close your browser window! The upload will stop if you close your browser. If the upload fails, you can click on the Retry button to start it again.
5. When the upload completes successfully, you will see a new row in your Extensions list with the status ENABLED - PENDING.

6. Before the extension can be available for use, it is necessary to restart the database. To perform this operation, click on the Apply changes button.
7. A new window will show you a list of the changes you are going to perform. Please review them and click on Apply changes.

Once the changes are applied, you will see the final status (ENABLED or DISABLED) in the list.

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Server extensions and stored procedures are shown together in your Extensions list.

Remove unmanaged server extensions

To remove an unmanaged server extension

• Navigate to the Extensions tab of your database dashboard
• Disable the server extension if it isn’t already disabled
  Click on the Remove link next to the extension.

Only disabled extensions can be removed. Make sure the extension is disabled before removing it.

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Danger

This action cannot be undone and will delete your server extension permanently.

GraphAware server extensions

GraphAware is a Neo4j Solution Partner that specializes in Neo4j consultancy, training, and development. They develop open-source tools and generic graph database extensions. Below, you can find more specific information about how to integrate GraphAware extensions.

Downloading GraphAware extensions

First, be sure to download a compatible version of the extension for your database. You can download the latest available version from the Graphaware product page or search for the proper version on Maven Central repository.

In some cases, the GraphAware Framework will be also be required. Just download the correct version and treat it as another server extension.

Configure your GraphAware extension

Please read the extension readme file carefully. This file will contain all of the needed instructions on how to configure the extension properly.

GraphAware extensions use neo4j.properties instead of neo4j-server.properties because their extensions work both in Server as well as in Embedded mode. Luckily, you don't have to worry about selecting the right file format, because when a GraphAware plugin is detected, GrapheneDB will automatically use the appropriate properties file.

Before uploading to GrapheneDB, please ensure you have packaged the extension tarball, the neo4j.properties file, and the framework tarball (if it's required) in a valid format (zip, tar, cpio, gz, bz2 or xz).

Add your GraphAware extension

Follow the steps described in Server extensions to upload and enable the GraphAware extension.