A graph database is all about relationships. Using nodes to store data entities and edges to store relationships between those identities, such databases are often the best solution for social networking, recommendation engines and fraud detection. For any use cases that require the ability to create relationships between data, the graph database is the way to go.
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Neo4j is one such database. It’s open source, uses an SQL-like query language, follows the Property Graph Data Model and supports indexes, UNIQUE constraints and full ACID rules. Let’s walk through the installation of the Neo4j graph database.
What you’ll need to install Neo4j
I’m going to demonstrate this on Ubuntu Server 22.04. For it to work, you’ll need a running instance of Ubuntu Server as well as a user with sudo privileges. The OS will need a minimum of a single CPU and 2GB of memory.
Do note this installation is for the free community edition. If you want a version of the database that offers unlimited horizontal scaling, fine-grained access controls, high availability and advanced manageability, you’ll need to use the Enterprise Edition. To find out about pricing for the Enterprise Edition, contact Neo4j sales.
How to install Neo4j
The first thing you’ll want to do is update and upgrade your server. Remember, if the kernel is upgraded, you must reboot the server for the changes to take effect. Because of that, you might want to hold off on upgrading until such a time as the server can safely be rebooted. If this isn’t a production server, you can do it any time you like.
To update and upgrade Ubuntu, log in to your server and issue the command:
sudo apt-get update && sudo apt-get upgrade -y
When the upgrade is finished, reboot if necessary.
Once the upgrade is completed, install the Neo4j dependencies with the command:
sudo apt-get install wget curl nano software-properties-common dirmngr apt-transport-https gnupg gnupg2 ca-certificates lsb-release ubuntu-keyring unzip -y
Next, you must add the official Neo4j GPG key with the command:
curl -fsSL https://debian.neo4j.com/neotechnology.gpg.key | sudo gpg --dearmor -o /usr/share/keyrings/neo4j.gpg
Add the Neo4j repository with:
echo "deb [signed-by=/usr/share/keyrings/neo4j.gpg] https://debian.neo4j.com stable latest" | sudo tee -a /etc/apt/sources.list.d/neo4j.list
Update apt with:
sudo apt-get update
Finally, install Neo4j with the command:
sudo apt-get install neo4j -y
When the installation is complete, start and enable the service with:
sudo systemctl enable --now neo4j
How to enable Neo4j connections from beyond localhost
At the moment, the only machine allowed to connect to the Neo4j server is localhost. If you’ll be using the database from machines other than the one it’s installed on, you’ll want to enable remote connections. To do that, open the Neo4j configuration file for editing with:
sudo nano /etc/neo4j/neo4j.conf
In that file, look for the following line:
Remove the #, so the line now reads:
Save and close the file with the CTRL+X keyboard shortcut. Restart the Neo4j service with:
sudo systemctl restart neo4j
You must also edit the system hosts file. To do that, issue the command:
sudo nano /etc/hosts
At the bottom of the file, add a line like this:
Where SERVER_IP is the IP address of the hosting server and HOSTNAME is the hostname of the machine. Save and close the file. For example, if your IP address is 192.168.1.7 and your hostname is fossa, the line would be:
How to test the Neo4j connection
To test the Neo4j connection, the command would look something like this:
cypher-shell -a 'neo4j://192.168.1.7:7687'
Both the default username and password are neo4j. After typing the default password, you’ll be prompted to create a new one. Once you’ve done that, you’ll find yourself at the Neo4j console.
If the connection fails, you might have to open the firewall on the server. To do that, you’ll also want to know the IP address of any machine that will connect to the server. For example, if you’re connecting from IP address 192.168.1.100, you could open the firewall with the command:
sudo ufw allow from 192.168.1.62 to any port 7687 proto tcp
If you want to open the connection to any machine on your network, that command might look like this:
sudo ufw allow from 192.168.1.0/24 to any port 7687 proto tcp
Simple install and powerful database
Neo4j might be the simplest graph database you can install for your project. To add to that simplicity, you get considerable power that will scale to meet your needs.
The only downsides to Neo4j are that it is limited to the number of nodes and it doesn’t support sharding. Other than that, you’ll find it an outstanding tool for your graph db projects.
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