ActiveGate works as a proxy between Dynatrace OneAgent and Dynatrace Server.
Note: "ActiveGate" is the name of the component that was previously known as "Security Gateway."
Main functions of ActiveGate
Message routing: ActiveGate knows about the runtime structure of your Dynatrace environment and routes messages from OneAgents to the correct server endpoints.
Buffering and compression: ActiveGate collects messages from OneAgent instances and builds bulks, which are then sent in compressed form to Dynatrace Server. Network overhead can thereby be considerably reduced—a 70% reduction can be expected.
Authentication: ActiveGate authenticates OneAgent requests (SSL handshake and environment ID authentication).
Entry point for sealed networks: Dynatrace Server clusters often run in protected environments that aren't directly accessible by OneAgent instances running outside of a sealed network. ActiveGate can be used to serve as a single access point for such OneAgent instances. In this way, maintenance overhead is reduced since you only need to provide access for one well-known ActiveGate (i.e., only a single exception rule in your firewall configuration settings is required).
Dynatrace supports two types of ActiveGates, Environment ActiveGates and Cluster ActiveGates. ActiveGates can be installed on Windows or Linux. With the Linux installer, you can use a number of command-line parameters. If you use Dynatrace SaaS, you only need to install an Environment ActiveGate. Dynatrace Managed deployments typically require both ActiveGate types, though the most important type for Managed is the Cluster ActiveGate.