io.helixservice.core.feature

Interface Feature

All Superinterfaces:

ComponentRegistry

All Known Implementing Classes:

AbstractFeature, BlockingWorkerFeature, VertxNativeFeature

public interface Feature
extends ComponentRegistry

Features allow modular addition of new functionality to the Helix Server.

Reusable features can be shared across teams. Each reusable feature should be built into in its own Maven artifact for ease of re-use across development teams.

Feature Concepts:

• Features are registered with the Helix Server
• Feature lifecycle is managed by the Helix Server
• Features own their Components, which they create, register, and destroy
• Features may define factory methods which can be called by other Features
• Features must track the resources (sockets, files, etc) they create

Method Summary

Modifier and Type	Method and Description
void	finish(Server server) Called by Helix Server when the server going to stop.
String	getFeatureName() Returns the name of this feature.
void	logFeatureDetails(org.slf4j.Logger logger) Logs the feature configuration to the provided logger.
void	start(Server server) Called by Helix Server when the server is starting.
void	stop(Server server) Called by Helix Server when the server has stopped.

Methods inherited from interface io.helixservice.core.component.ComponentRegistry

findByType, findByType, getRegistrationMap

Method Detail

getFeatureName

String getFeatureName()

Returns the name of this feature.

Returns:

Feature name. By default, this is the Java class name.

logFeatureDetails

void logFeatureDetails(org.slf4j.Logger logger)

Logs the feature configuration to the provided logger. Primarily used on server startup to expose the Helix Server configuration

Parameters:

logger - Logger to write the feature details to

start

void start(Server server)

Called by Helix Server when the server is starting.

The order features will be called is the same order they initially registered with Helix. At the time this method is called, Vert.x will be initialized enabling the feature to create any Vert.x related resources.

Features should create and register any singleton components and allocate resources during the start call. Blocking operations are allowed in this method.

Parameters:

server - Helix Server that is starting up

finish

void finish(Server server)

Called by Helix Server when the server going to stop.

The order features will be called is the reverse order they initially registered with Helix. Features should NOT release resources at this point.

Stop accepting new requests, and finish all ongoing requests. There will be a configurable delay between the finish and stop lifecycle callbacks to enable the server to finish in-flight requests.

Parameters:

server - Helix Server that is finishing in-flight requests

stop

void stop(Server server)

Called by Helix Server when the server has stopped.

The order features will be called is the reverse order they initially registered with Helix. Features must release all owned resources at this point. Blocking operations are allowed in this method.

Parameters:

server - Helix Server that is being stopped