OrientDB is an open source NoSQL database management system written in Java. It is a Multi-model database, supporting graph, document, key/value, and object models but the relationships are managed as in graph databases with direct connections between records. It supports schema-less, schema-full and schema-mixed modes. It has a strong security profiling system based on users and roles and supports querying with Gremlin along with SQL extended for graph traversal. OrientDB uses several indexing mechanisms based on B-tree and Extendible hashing, the last one is known as “hash index”, there are plans to implement LSM-tree and Fractal tree index based indexes. Each record has Surrogate key which indicates position of record inside of Array list , links between records are stored either as single value of record’s position stored inside of referrer or as B-tree of record positions (so-called record IDs or RIDs) which allows fast traversal (with O(1) complexity) of one-to-many relationships and fast addition/removal of new links. OrientDB is the third most popular graph database according to the DB-Engines graph database ranking, as of September 2017.
Step 1: Install necessary packages
Install wget and unzip using below commands
dnf install -y wget unzip
Step 2: Install and Configure Open JDK
dnf install -y java-1.8.0-openjdk
Set Java’s Home Environment
Run below command to find java path
update-alternatives --config java
In my case it is /usr/lib/jvm/java-1.8.0-openjdk-1.8.0.222.b10-0.el8_0.x86_64/jre/bin/java
Now Set Java’s Path in Your Environment using below command
vi .bash_profile
Add below line in .bash_profile file
export JAVA_HOME=/usr/lib/jvm/java-1.8.0-openjdk-1.8.0.222.b10-0.el8_0.x86_64/jre/bin/java
Save changes and Exit.
Refresh .bash_file to make changes
source .bash_profile
Run below commands to see the Java path you set and the java version.
echo $JAVA_HOME java -version
Step 3: Install OrientDB
It is recommended to run OrientDB as its own user. Run the following command to create the user orientdb and set its home directory to /opt/orientdb.
adduser orientdb -d /opt/orientdb
Download the OrientDB binary archive by running the following commands
Note: You can get lestest version of OrientDb from OrientDB download page.
cd /opt/orientdb/ wget https://orientdb3.s3.us-east-2.amazonaws.com/releases/3.0.23/orientdb-3.0.23.tar.gz -O orientdb.tar.gz
Extract the archive and move files.
tar -xf orientdb.tar.gz ls mv orientdb-3.0.23/* .
Remove unnecessary data.
rm -rf orientdb-3.0.23 orientdb.tar.gz
Set appropriate permissions to the OrientDB user.
chown -R orientdb:orientdb /opt/orientdb
OrientDB has been installed on your RHEL / CentOS 8 server.
Start OrientDb Server
Switch to the OrientDB user and run script.
su - orientdb bin/server.sh
You will be asked to set the password of the OrientDB root user like image below, set the password and press enter.
Now you should see image like below, It OrientDb server is started successfully.
press ctrl + C to stop the execution.
Now switch again to root user by running below command.
exit
Step 4: Configure OrientDB Systemd Service
To start OrientDb service automatically on system boot, create a new systemd service by running the following command
vi /etc/systemd/system/orientdb.service
Now add following lines in that file.
[Unit] Description=OrientDB service After=network.target [Service] Type=simple ExecStart=/opt/orientdb/bin/server.sh User=orientdb Group=orientdb Restart=always RestartSec=9 StandardOutput=syslog StandardError=syslog SyslogIdentifier=orientdb [Install] WantedBy=multi-user.target
Save change to file and exit.
Now you can start and enable OrientDB service on boot.
systemctl start orientdb systemctl enable orientdb systemctl status orientdb
Create a soft link for the OrientDB script which starts the console for OrientDB. so we can easily switch to the OrientDB console.
ln -s /opt/orientdb/bin/console.sh /usr/bin/orientdb
Now we can access the OrientDB console by running below command.
orientdb
To exit the OrientDB console using below command
exit
Step 5: Access OrientDB from GUI:
OrientDB Studio is a web based GUI tool to easily administrator OrientDB. It is also installed along with OrientDB package. Once you start OrientDB server, Studio is also started along with it.
We need to allow port 2480 in firewall in order to access OrientDb web interface. Run following commands to add port in firewalld.
firewall-cmd --zone=public --permanent --add-port=2480/tcp firewall-cmd --reload
Now open the following web address in your browser.
http://your-server-IP:2480
You will see below page on you screen
To create a new database click on NEW DB button and enter name of desired database you want to create.
Now type name of the database and root as the Server User and enter the password of the root user which was set during the installation. Finally Click on CREATE DATABASE to create a new database and you will see the dashboard to manage the database.
