org.apache.samza.context

Interface ApplicationContainerContext

public interface ApplicationContainerContext

An ApplicationContainerContext instance can be used for holding per-container runtime state and objects and managing their lifecycle. This context is shared across all tasks in the container.

Use ApplicationDescriptor.withApplicationContainerContextFactory(org.apache.samza.context.ApplicationContainerContextFactory<?>) to provide the ApplicationContainerContextFactory. Use Context.getApplicationContainerContext() to get the created ApplicationContainerContext instance for the current container.

A unique instance of ApplicationContainerContext is created in each container. If the container moves or the container model changes (e.g. due to failure or re-balancing), a new instance is created.

Use the ApplicationContainerContextFactory to create any runtime state and objects, and the start() and stop() methods to manage their lifecycle.

Use ApplicationTaskContext to hold unique runtime state and objects for each task within a container. Use ContainerContext to access framework-provided context for a container.

Unlike its ApplicationContainerContextFactory, an implementation does not need to be Serializable.

Method Summary

Modifier and Type	Method and Description
void	start() Starts this ApplicationContainerContext before any tasks in the container are initialized and before processing begins.
void	stop() Stops this ApplicationContainerContext after processing ends and after all tasks in the container are closed.

Method Detail

start

void start()

Starts this ApplicationContainerContext before any tasks in the container are initialized and before processing begins.

If this throws an exception, the container will fail to start.

stop

void stop()

Stops this ApplicationContainerContext after processing ends and after all tasks in the container are closed.

If this throws an exception, the container will fail to fully shut down.