An agent is a lightweight process that runs on a target host and communicates with the Serena Release Automation server. Agents perform the actual work of deploying components and so relieves the server from the task, making large deployments involving thousands of targets possible. Usually, an agent runs on the same host where the resources it handles are located; a single agent can handle all the resources on its host. If a host has several resources, an agent process is invoked separately for each one. Depending on the number of hosts in an environment, a deployment might require a large number of agents.

Agents are installed with the batch files provided with the installation files, see the section called “Agent Installation”. Agents that will be installed on Unix machines can also be installed remotely using Serena Release Automation's web application, which is described below. Agents are run using the batch files included with the installation package.

Once an installed agent has been started, the agent opens a socket connection to the Serena Release Automation server (securable by configuring SSL for server-agent communication) based on the information supplied during installation. Agents on networks other than the one where the server is located might need to open a firewall to establish connection. Once communication is established, the agent will be visible in the Serena Release Automation web application where it can be configured. Active agents–regardless of OS–can be upgraded using the web application.

Agent configuration consists of assigning an agent to at least one environment; agents can be assigned to multiple environments. If an agent is assigned to several environments, it can perform work on behalf of all of them.