Best Practices from Oracle Development's A‑Team

Deploying Connection Manager as a Proxy for Oracle Services

Validated May 25, 2021


Oracle Services may require a proxy to reach data sources for various reasons including security, routing and privacy. For use cases requiring sophisticated functionality, Oracle's Connection Manager provides database transparency, high-availability, protocol conversion and enhanced security, scalability and performance.

This post is a step-by-step guide for deploying Connection Manager on Linux with a simple starter configuration.

Refer to Understanding Oracle Connection Manager Architecture for details on the architecture shown below.


Primary Uses

The primary uses of Connection Manager for Oracle Services are private egress,  transparency,  and protocol conversion.

Private Egress provides access to private databases.

Transparency hides the details of connecting to unsupported databases or those with complex connection criteria. It allows users to think that they are connecting to a single-instance Oracle database using just a host, port, and service name. Connection Manager stores the connection complexities for all users and applications. When it receives a request, it connects to the target database for session creation. The database receives the actual user, application and network address for its session details.

Protocol Conversion converts TCP traffic to TCPS used by Autonomous Databases (ADB). This feature along with transparency further simplifies the user experience by hiding the need for Secure Socket Layer wallets and associated networking parameters. Connection Manager stores complex TCPS wallet placement and handshake parameters for all users and applications. When it receives a request, it forwards it on to the SSL-protected database for session creation.

Additional Uses

Additional uses of Connection Manager are access control and anonymity.

Access Control provides solutions for database access when a database subnet allows ingress only from designated application subnets. A Connection Manager instance in such a subnet receives connection requests and connects to the databases on the application's behalf.

Anonymity builds on transparency by hiding the application from the database. The database only receives Connection Manager's proxy user and network address for its session details.


May 25, 2021 with GoldenGate 21.1

February 2, 2021 with FAW 5.8 and OAC 5.9 


Before You Begin

Deploying Required Components

Installing Connection Manager

Configuring Connection Manager

Validating Connection Manager

 Before You Begin and Assumptions 


FAW Fusion Applications Warehouse
OAC Oracle Analytics Cloud
PE Private Endpoint
CMAN Connection Manager
DB Database
DV Data Visualization
OCI Oracle Cloud Infrastructure
FQDN Fully Qualified Domain Name
PAC Private Access Channel
OSN Oracle Services Network



A user account in an OCI tenancy for managing compute and networking components.


 Deploying Required Components 

The following components must exist before installing and validating CMAN.

VCN Hosts the CMAN subnet Link
COMPUTE INSTANCE Hosts the CMAN application Link
ACCESS RULES Facilitates network traffic between Services and CMAN Link


Virtual Cloud Network

Create a new VCN using the OCI networking QuickStart wizard.




Create or use an existing public subnet in the VCN chosen above. This post uses a subnet named APP-Subnet in its examples.



CMAN Compute Instance

Create a small Linux instance to initially host CMAN in the APP-Subnet.



Prepare an SSH Alias for CMAN

On your client prepare an SSH alias. Windows users may either install SSH or use PuTTY.

Access Control

Define ingress rules for network traffic between clients and CMAN.

VCN1-APP-SL INGRESS CLIENT TCP 1521   Ingress to CMAN Listener
VCN1-APP-SL INGRESS CLIENT TCP 22   SSH Ingress from Client


 Installing Connection Manager 

Connection Manager Download

Download the appropriate CMAN software from here e.g. LINUX.X64_193000_client.zip. Copy the file to the compute instance if necessary.

Connect to the CMAN host

Prepare the CMAN host

Open the CMAN Port

Install an Oracle Installer Prerequisite Package

Note: This package also creates an oracle user.

Grant sudo Privilege to Oracle

Begin SSH access for Oracle

Change to the Oracle User

Complete SSH access for Oracle

Exit and Connect to the CMAN host

Set the ORACLE_BASE, ORACLE_HOME, TNS_ADMIN and PATH Environment Variables

Unzip the CMAN Download

Create a CMAN Response File

Create a response file e.g. cman.rsp  to be used with silent installation mode.

Run the Installer

Post-Install Steps

Run the Root Scripts


 Configuring Connection Manager 

This section configures a starter CMAN instance. Refer here for complete documentation. 

Create a Starter Configuration File

The CMAN configuration file cman.ora format is based on an Oracle Database Listener configuration file listener.ora format with additional options. Each CMAN instance defined in the file includes the following components:

Instance Name
Listening Endpoint
Access Rule List
Parameter List

The minimum required components are an instance, listening endpoint and an access rule. The parameter list is omitted here as the defaults are sufficient to start with. The access rule is set to allow all traffic. Modify this if necessary after a successful installation.


CMAN Enabled State

℘ Validating Connection Manager 

Validating the introductory deployment of CMAN involves starting it and successfully connecting to it using SQL*Plus. Start CMAN using the Connection Manager Control Utility

Start CMAN

You see:

Connect with SQL*Plus

Use a dummy username, password and service name. We are only testing if CMAN is listening.


If CMAN is listening you see:

ORA-12514: TNS:listener does not currently know of service requested in connect

If CMAN is not listening you see:

ORA-12541: TNS:no listener


This post provided a step-by-step guide for deploying Oracle Connection Manager on Linux with a simple starter configuration. You are now ready to create a connection to a private data source using Connection Manager.

For other posts relating to analytics and data integration visit http://www.ateam-oracle.com/dayne-carley


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