Configuration Injection

Discover Config Injected Objects

@com.neeve.server.app.annnotationsannotations.AppConfiguredAccessor
public void addConfiguredObjects(Set<Object> objects) {...}

Config Injection

After retrieving the set of config injected objects, the Talon XVM introspects the objects and injects configuration as described in Annotation Driven Config.

Get AppStat Containers

// Note that the method name is unimportant.
@com.neeve.server.app.annnotationsannotations.AppStatContainerAccessorAppStatContainersAccessor
public void addAppStatContainerObjects(Set<Object> containers) {...} 

Discover AppStats

AppStats can be be exposed by either methods or fields on the App's main class or in one of the AppStatContainers exposed above by annotating the field or method with the @com.neeve.server.app.annotations.AppStat annotation. Introspection for application stats is done just before the AepEngine is injected into the application. See User-Defined App Stats for additional details. 

annotations.AppInjectionPoint
public void setEngine(final com.neeve.aep.AepEngine engine) {...}

Initialize Application

The final step in this phase of the application lifecycle is to initialize the application. This is done via the method on the application's main class annotated with the @com.neeve.server.app.annotations.AppInitializer annotation.

@com.neeve.server.app.

annotations.AppInitializer
public void initialize() {...}

Start Phase

Start Engine

The only act performed in the start phase is to start the engine. The act of starting the engine will determine whether the started engine is the primary or a backup in the application's cluster. If primary, messages will start flowing to the application. If backup, messages and/or state will be replicated in real time from the primary to the backup to keep the backup's state in sync with the primary. If the primary fails, the backup elected as primary will open its messaging machinery and messages will start flowing to the application for processing. See below for more detail on the engine start flow.

Run Phase

Event Driven Applications

X Applications are message/event driven applications. For such applications, nothing additional needs to be done to enter the run phase. Once the engine has been started, messages and/or events will be dispatched to the application thus driving its operation. 

Synchronous Applications

For applications that are not event driven, i.e. "sender" only type applications that synchronously drive their own operation, the server provides the facility for the applications to implement the "main" method. The server identifies the method in the application's main class annotated with @com.neeve.server.app.annotations.AppMain to be the application's main method. If such a method is discovered, then the server spins up a separate thread that invokes the application main method. The following is an example of an application main method.

@com.neeve.server.app.

annotations.AppMain
public void main() {...}

Stop Phase

Stop Engine

The only act performed in the stop phase is to stop the engine. See below for more detail on the engine stop flow.

Close Phase

Finalize Application

The last step executed by the Talon XVM in the application lifecycle is to invoke the application's finalize method, i.e. the method in the application's main class annotated with the @com.neeve.server.app.annotations.AppFinalizer annotation

@com.neeve.server.app.

annotations.AppFinalizer
public void finalise() {...}

Engine Lifecycle

The following depicts the overall lifecycle of an AEP engine. 

Create Engine

The following depicts the creation flow of an AEP engine.