Oracle Cloud Infrastructure Documentation

Connecting to an Exadata Cloud at Customer System

This topic explains how to connect to an Exadata Cloud at Customer system using SSH, and how to connect to an Exadata Cloud at Customer database using Oracle Net Services (SQL*Net).

Connecting to a Compute Node with SSH

You can connect to the compute nodes in an Exadata Cloud at Customer system by using a Secure Shell (SSH) connection. Most UNIX-style systems (including Linux, Solaris, BSD, and OS X) include an SSH client. For Windows, you can download a free SSH client called PuTTY from http://www.putty.org.

Prerequisites

To access a compute node in an Exadata Cloud at Customer system by using SSH, you need the following:

  • An SSH private key file that corresponds to a public key that is registered in the system.

    When you create a VM cluster on your Exadata Cloud at Customer system, you must specify the public key portion of one or more SSH key pairs. You can also register extra keys separately after you create the VM cluster. The public keys are stored in the authorized_keys file at ~/.ssh/authorized_keys. Separate authorized_keys files are located under the home directories of the oracle and opc OS users.

  • The host name or IP address for the compute node that you want to access.

    See To check the status of a VM cluster compute node.

To connect from a UNIX-style system
To connect from a Windows system using PuTTY
To access a database after you connect to the compute node

Connecting to a Database with Oracle Net Services

Oracle Database Exadata Cloud at Customer supports remote database access by using Oracle Net Services.

Because Exadata Cloud at Customer uses Oracle Grid Infrastructure, you can make Oracle Net Services connections by using Single Client Access Name (SCAN). SCAN is a feature that provides a consistent mechanism for clients to access the Oracle databases running in a cluster.

By default, the SCAN is associated with three virtual IP addresses (VIPs). Each SCAN VIP is also associated with a SCAN listener that provides a connection endpoint for Oracle Database connections using Oracle Net Services. To maximize availability, Oracle Grid Infrastructure distributes the SCAN VIPs and SCAN listeners across the available cluster nodes. In addition, the SCAN VIPs and SCAN listeners are automatically migrated to a surviving node if there is a node shutdown or failure. The aim is to ensure that Oracle Database clients always have a reliable set of connection endpoints that can service all of the databases running in the cluster.

The SCAN listeners are in addition to the Oracle Net Listeners that run on every node in the cluster, which are also known as the node listeners. When an Oracle Net Services connection comes through SCAN, the SCAN listener routes the connection to one of the node listeners and plays no further part in the connection. A combination of factors, including listener availability, database instance placement, and workload distribution, determines which node listener receives each connection.

Note

This section outlines the basic requirements for connecting to your Exadata Cloud at Customer databases by using Oracle Net Services. For more guidance on achieving continuous service during planned maintenance, node failure, or Oracle Database instance failure, see the Continuous Availability white paper.

Prerequisites

To connect to an Exadata Cloud at Customer database by using Oracle Net Services, you need the following:

  • The IP addresses for your SCAN VIPs, or the hostname or IP address for a compute node that hosts the database that you want to access.
  • The database identifier, either the database SID or service name.
To connect using SCAN
To connect using a node listener