https://docs.oracle.com/en/cloud/paas/integration-cloud/integrations-user/agent-download-and-installation.html#GUID-0FA73D40-D238-46AD-A347-BB97D513FEB0
Use the Agent in High Availability Environments
You can use the connectivity agent in high availability environments. You install the connectivity agent twice on different hosts. There are no differences in agent installation. You specify the same agent group identifier during both installations.
Note the following details:
The File Adapter is not supported in high availability environments. When using the File Adapter and some groups have multiple instances, use a dedicated agent group (with one agent only).
Any new agent group created is enabled for high availability. Existing agent groups created prior to high availability being supported have no high availability capabilities and cannot be used.
You cannot have more than two agent instances per agent group. Attempting to include a third agent instance in the same group during installation results in an error.
While you can install up to two agent instances per agent group, be aware of the current restriction with agent high availability when working in tandem with automatically upgraded agents. To ensure that both agent instances do not upgrade at the exact same time, it is recommended that you start each instance with a small time gap. The time gap can be as little as 10 minutes. This ensures that there is no outage due to both agent instances being upgraded at the same time.
Ensure that both agent instances can access the same endpoints. For example, agent 1 on host 1 and agent 2 on host 2 must both be able to access the same endpoint (for example, a Siebel system).
Both hosts on which the agent is installed must have the same network setup.
To enable an older agent integration for high availability, you must create a new group, update the adapter connections in the integration to refer to the new group, and re-activate the integration.
You can install multiple agents on the same host. However, to utilize high availability capabilities, install the second agent on a second host.
Create a horizontal cluster to achieve high availability. Installing the agent on the same virtual machine (VM) does not guarantee high availability.
https://docs.oracle.com/en/cloud/paas/integration-cloud/integrations-user/use-agent-high-availability-environments.html