Installing an Agent (Linux OS)

You can enable database audit only after the agent is installed. This topic describes how to install the agent on a node running a Linux OS.

Prerequisites

You have applied for a database audit instance and the Status is Running.
You have added an agent to your database.
You have obtained the agent installation package for the Linux OS.
The Linux OS version of the target node is supported by the agent.

Scenarios

You can install the agent on the database or application side, depending on your database type and deployment scenario. Common database scenarios are as follows:

Deploy DBSS for databases built on ECS/BMS. For details, see Figure 1 and Figure 2.
Figure 1 One application connecting to multiple databases built on ECS/BMS

Figure 2 Multiple applications connecting to one database built on ECS/BMS
Deploy DBSS for RDS databases. For details, see Figure 3 and Figure 4.
Figure 3 One application connecting to multiple RDS databases

Figure 4 Multiple applications connecting to one RDS database

Table 1 describes where to install the agent in the preceding scenarios.

If your applications and databases (databases built on ECS/BMS) are deployed on the same node, install the agent on the database side.

**Table 1** Agent installation scenarios
Scenario	Where to Install Agent	Audit Scope	Description
Self-built database on ECS/BMS	Database	All access records of applications that have accessed the database	Install the agent on the database side. If an application connects to multiple databases built on ECS/BMS, the agent must be installed on all these databases.
RDS database	Application side (if applications are deployed on the cloud)	Access records of all the databases connected to the application	Install the agent on the application side. If multiple applications are connected to the same RDS database, the agent must be installed on all these applications.
RDS database	Proxy side (if applications are deployed off the cloud)	Only the access records between the proxy and database. Those between the applications and database cannot be audited.	Install the agent on the proxy side.

Installing an Agent

Install the agent on the node suitable for your service scenario.

Upload the downloaded agent installation package xxx.tar.gz to the node (for example, using WinSCP).
Log in to the node as user root using SSH through a cross-platform remote access tool (for example, PuTTY).
Run the following command to access the directory where the agent installation package xxx.tar.gz is stored:

cd Directory_containing_agent_installation_package
Run the following command to decompress the installation package xxx.tar.gz:

tar -xvf xxx.tar.gz
Run the following command to switch to the directory containing the decompressed files:

cd Decompressed_package_directory
Run the following command to check whether you have the permission for executing the install.sh script:

ll
- If you do, go to 7.
- If you do not, perform the following operations:
  1. Run the following command to get the script execution permission:
    chmod +x install.sh
  2. Verify you have the required permissions.

Run the following command to install the agent:

sh install.sh

In Ubantu, run the following command to install the agent:

bash install.sh

If the following information is displayed, the agent has been installed. Otherwise, the installation fails.

start agent
starting audit agent
audit agent started
start success
install dbss audit agent done!

If the agent installation failed, ensure the OS version of the target node is supported and try again.

Run the following command to view the running status of the agent program:

service audit_agent status
If the following information is displayed, the agent is running properly:
```
audit agent is running.
```