Package org.apache.fluo.api.observer

Interface ObserverProvider

public interface ObserverProvider

Fluo Workers use this class to register Observers to process notifications. Implementations of this class should register zero or more Observers.

When Fluo is initialized provideColumns(BiConsumer, Context) is called. The columns it registers are stored in Zookeeper. Transactions will use the columns stored in Zookeeper to determine when to set notifications. When Workers call provide(Registry, Context), the columns registered must be the same as those registered during initialization. If this is not the case, then the worker will fail to start.

Since:

1.1.0

See Also:

FluoConfiguration.setObserverProvider(String)

Nested Class Summary

Nested Classes

Modifier and Type	Interface	Description
static interface	ObserverProvider.Context
static interface	ObserverProvider.Registry	Observers are registered with the worker using this interface.

Method Summary

Modifier and Type	Method	Description
void	provide(ObserverProvider.Registry or, ObserverProvider.Context ctx)	This is method is called by Fluo Workers to register observers to process notifications.
default void	provideColumns(BiConsumer<Column,Observer.NotificationType> colRegistry, ObserverProvider.Context ctx)	Called during Fluo initialization to determine what columns are being observed.

Method Detail

provide

void provide(ObserverProvider.Registry or,
             ObserverProvider.Context ctx)

This is method is called by Fluo Workers to register observers to process notifications.

Observers registered may be called concurrently by multiple threads to process different notifications. Observers should be tolerant of this.

Parameters:

or - Register observers with this.

provideColumns

default void provideColumns(BiConsumer<Column,Observer.NotificationType> colRegistry,
                            ObserverProvider.Context ctx)

Called during Fluo initialization to determine what columns are being observed. The default implementation of this method calls provide(Registry, Context) and ignores Observers.

Parameters:

colRegistry - register all observed columns with this consumer