NOM persistence DBMS

Server installation is a two-step process. The first step, as described in this section, is to set up a Neo4j DBMS to act as persistence storage for NOM.

The NOM persistence DBMS is used to store all NOM data (topology, metrics, etc.). The DBMS and the NOM Server need to be running simultaneously, or the NOM Server will not work.

Self managed DBMS

NOM comes with a license to run a Neo4j DBMS with up to 4 cores of CPU and up to 16 GB of RAM for the use as NOMs persistence.

Specifications

Neo4j Enterprise Edition 4.4 or 5.x
At least 10 GB free disk space
For minimum requirements, see also Operations Manual → System requirements.

Install and prepare

Please refer to the Operations Manual → Installation for information on how to install Neo4j.
Make sure to set a secure password for the built-in admin (neo4j) and/or create a specific user for the NOM Server. Be aware that that user needs full admin access. The login to the NOM Server is needed for server installation.

AuraDB

An AuraDB Professional or Enterprise could be used for NOM persistence however consideration should be given to the following:

The AuraDB instance should be for exclusive use of the NOM server.
The NOM server and persistence should ideally be located on the same LAN segment to avoid performance being impacted by WAN traffic.
Future product developments may require features not currently available in AuraDB.

If the DBMS is not newly created, ensure the following:

That the default database for the user exists. This is done via the SHOW DATABASES command.
That the default database for the user is empty. This is done via MATCH (n) RETURN count(n) which should return 0.
That the default database for the user doesn’t contain any indexes or constraints. This is done via SHOW INDEXES and SHOW CONSTRAINTS.

The default database for a user is either the home database for that user if it is set or the default database for the DBMS. The default database for the DBMS is 'neo4j' if not explicitly configured.

The use or manipulation of the persistence database apart from through the NOM Server is highly discouraged and can negatively impact the stability and data correctness of NOM.