Installing Oracle Graph Server

1.3.1 Installing Oracle Graph Server

The prerequisites for installing the Oracle Graph Server are:

Oracle Linux 6 , 7 or 8 x64 or a similar Linux distribution such as RedHat (Using the Machine Learning Library (PgxML) for Graphs requires Oracle Linux 7 or later)
Oracle JDK 8 or JDK 11
Note:

Due to a bug in Open JDK, it is recommended to avoid the following Oracle JDK versions:
- JDK 11.0.9
- JDK 11.0.10
- JDK 11.0.11
- JDK 11.0.12
See this note for more details.

You can run Oracle Graph Server in standalone mode or using a webserver like Oracle WebLogic Server or Apache Tomcat.

The installation steps for installing Oracle Graph Server in standalone mode are as shown:

As a root user or using sudo, install the RPM file using the rpm command line utility:
```
sudo rpm -i oracle-graph-<version>.rpm
```
Where <version> reflects the version that you downloaded. (For example: oracle-graph-21.4.0.0.0.x86_64.rpm)

The .rpm file is the graph server.
The following post-installation steps are carried out at the time of the RPM file installation:
- Creation of a working directory in /opt/oracle/graph/pgx/tmp_data
- Creation of a log directory in /var/log/oracle/graph
- Installation of Python Client
  
  Note:
  If Python is not installed in your system, then this step will be skipped.
- Automatic generation of self-signed TLS certificates in /etc/oracle/graph
  Note:
  
  You can also choose to configure and set up transport layer security (TLS) in graph server. See Setting Up Transport Layer Security for more details.
  
  For demonstration purposes, if you wish to disable transport layer security (TLS) in graph server, see Disabling Transport Layer Security (TLS) in Graph Server for more details.
As root or using sudo, add operating system users allowed to use the server installation to the operating system group oraclegraph. For example:
```
usermod -a -G oraclegraph <graphuser>
```
This adds the specified graph user to the group oraclegraph.
Note that <graphuser> must log out and log in again for this to take effect.
As <graphuser>, configure the server by modifying the files under /etc/oracle/graph by following the steps under Prepare the Graph Server for Database Authentication.
Ensure that authentication is enabled for database users that will connect to the graph server, as explained in User Authentication and Authorization.
As a root user or using sudo, start the graph server (PGX) by executing the following command:
```
sudo systemctl start pgx
```

You can verify if the graph server has started by executing the following command:

systemctl status pgx

If the graph server has successfully started, the response may appear as:

● pgx.service - Oracle Graph In-Memory Server
   Loaded: loaded (/etc/systemd/system/pgx.service; disabled; vendor preset: disabled)
   Active: active (running) since Wed 2021-01-27 10:06:06 EST; 33s ago
 Main PID: 32127 (bash)
   CGroup: /system.slice/pgx.service
           ├─32127 /bin/bash start-server
           └─32176 java -Dlog4j.configurationFile=/etc/oracle/graph/log4j2-server.xml -Doracle.jdbc.fanEnabled=false -cp /opt/oracle/graph/pgx/bin/../../pgx/server/lib/activat...

The graph server is now ready to accept requests.

If the graph server has not started, then you must check the log files in /var/log/oracle/graph for errors. Additionally, you can also run the following command to view any systemd errors:
```
sudo journalctl -u pgx.service 
```

Additional installation operations are required for specific use cases, such as:

Analyze property graphs using Python (see Installing the Python Client).
Deploy the graph server as a web application with Oracle WebLogic Server (see Deploying to Oracle WebLogic Server).
Deploy GraphViz in Oracle WebLogic Server (see Deploying the Graph Visualization Application in Oracle WebLogic Server).
Deploy the graph server as a web application with Apache Tomcat (see Deploying to Apache Tomcat).

For instructions to deploy the graph server in Oracle WebLogic Server or Apache Tomcat, see:

Parent topic: Oracle Graph Server and Client Installation