Application Activation Modes

Activation mode for an application defines the way an application is loaded, initiated and started when deployed to an AppSpace.

By choosing the appropriate activation mode, the component in an application module can be configured to be active in multiple AppNodes or in a single AppNode. When configured to be active in a single AppNode, the component is active in a single AppNode and in a passive state in all the other AppNodes of the AppSpace.

A component in an active state is loaded, initialized and enabled to process new events. A component in a passive state is loaded, initialized; however it is not enabled to process new events, instead it is in a stand-by mode. When a component is active in multiple AppNodes, it is considered to be Active-Active. And when a component is active in a single AppNode and passive in other AppNodes, it is considered to be Active-Passive.

The component's activation mode is determined by the process that implements the component. At design-time, the process that is implemented by a component in an application module can be configured to be active in a single AppNode (Active-Passive) or in multiple AppNodes (Active-Active). To do so, set the Activation field on the Advanced tab of the Properties view as shown:

Note: If the activation mode for a process is set to Multiple AppNodes, then the activation mode for all the sub-processes and child processes (other processes that are called by the process or one of its child processes) must be set to Multiple AppNodes as well. Failure to do so can result in a design-time validation error.
Important: Enabling the activation mode for an application requires both design-time and runtime configurations as described in the following sections.

Active-Active (Multiple AppNodes)

In active-active mode, an application is loaded, initiated, and ready to run on all the AppNodes in the AppSpace. Enabling an application for active-active mode requires both design-time and runtime configurations. Perform the following steps to configure an application for active-active mode:
  • Design-time: Set the activation mode of the component process to Multiple AppNodes. The Activation field is configurable from the Advanced tab of the Properties view for the process.
  • Runtime: The engine persistence mode must be set to group to enable the engines running in the AppNodes to be aware of the existence of other engines in the AppSpace and provide managed fault tolerance feature. See Engine Persistence Modes for details about persistence modes. See Managed Fault Tolerance for details on how to configure the runtime.
Active-Active Mode

Active-Passive (Single AppNode)

In active-passive mode, an application is loaded on all the AppNodes in the AppSpace, and is activated to run on a single AppNode at any given time. Enabling an application for active-passive mode requires both design-time and runtime configurations. Perform the following steps to configure an application for active-passive mode:
  • Design-time: Set the activation mode of the component process to Single AppNode. The Activation field is configurable from the Advanced tab of the Properties view for the process.
  • Runtime: The engine persistence mode must be set to group to enable the engines running in the AppNodes to be aware of the existence of other engines in the AppSpace and provide managed fault tolerance feature. See Engine Persistence Modes for details about persistence modes. See Managed Fault Tolerance for details on how to configure the runtime.
Active-Passive Mode
Note: When an application is running in active-passive mode on multiple AppNodes, stopping an application instance that is active in an AppNode does not trigger the passive application instances in other AppNodes to become active. The only way a passive application instance in an another AppNode becomes active is when the AppNode that contains the active application is terminated.