co.cask.cdap.messaging.distributed

Class LeaderElectionMessagingService

java.lang.Object

com.google.common.util.concurrent.AbstractIdleService

co.cask.cdap.messaging.distributed.LeaderElectionMessagingService

All Implemented Interfaces:

MessagingService, com.google.common.util.concurrent.Service

public class LeaderElectionMessagingService
extends com.google.common.util.concurrent.AbstractIdleService
implements MessagingService

A MessagingService that performs lead-election and only operates if it is currently a leader.

Nested Class Summary

Nested classes/interfaces inherited from interface com.google.common.util.concurrent.Service

com.google.common.util.concurrent.Service.Listener, com.google.common.util.concurrent.Service.State

Method Summary

Modifier and Type	Method and Description
void	createTopic(TopicMetadata topicMetadata) Creates a topic with the given metadata.
void	deleteTopic(co.cask.cdap.proto.id.TopicId topicId) Deletes a topic
TopicMetadata	getTopic(co.cask.cdap.proto.id.TopicId topicId) Returns the metadata of the given topic.
List<co.cask.cdap.proto.id.TopicId>	listTopics(co.cask.cdap.proto.id.NamespaceId namespaceId) Returns the list of topics available under the given namespace.
MessageFetcher	prepareFetch(co.cask.cdap.proto.id.TopicId topicId) Prepares to fetch messages from the given topic.
RollbackDetail	publish(StoreRequest request) Publishes a list of messages to the messaging system.
void	rollback(co.cask.cdap.proto.id.TopicId topicId, RollbackDetail rollbackDetail) Rollbacks messages published to the given topic with the given transaction.
protected void	shutDown()
protected void	startUp()
void	storePayload(StoreRequest request) Stores a list of messages to the messaging system.
void	updateTopic(TopicMetadata topicMetadata) Updates the metadata of a topic.

Methods inherited from class com.google.common.util.concurrent.AbstractIdleService

addListener, executor, isRunning, start, startAndWait, state, stop, stopAndWait, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

startUp

protected void startUp()
                throws Exception

Specified by:

startUp in class com.google.common.util.concurrent.AbstractIdleService

Throws:

Exception

shutDown

protected void shutDown()
                 throws Exception

Specified by:

shutDown in class com.google.common.util.concurrent.AbstractIdleService

Throws:

Exception

createTopic

public void createTopic(TopicMetadata topicMetadata)
                 throws co.cask.cdap.api.messaging.TopicAlreadyExistsException,
                        IOException

Description copied from interface: MessagingService

Creates a topic with the given metadata.

Specified by:

createTopic in interface MessagingService

Parameters:

topicMetadata - topic to be created

Throws:

co.cask.cdap.api.messaging.TopicAlreadyExistsException - if the topic to be created already exist

IOException - if failed to create the topic

updateTopic

public void updateTopic(TopicMetadata topicMetadata)
                 throws co.cask.cdap.api.messaging.TopicNotFoundException,
                        IOException

Description copied from interface: MessagingService

Updates the metadata of a topic.

Specified by:

updateTopic in interface MessagingService

Parameters:

topicMetadata - the topic metadata to be updated

Throws:

co.cask.cdap.api.messaging.TopicNotFoundException - if the topic doesn't exist

IOException - if failed to update the topic metadata

deleteTopic

public void deleteTopic(co.cask.cdap.proto.id.TopicId topicId)
                 throws co.cask.cdap.api.messaging.TopicNotFoundException,
                        IOException

Description copied from interface: MessagingService

Deletes a topic

Specified by:

deleteTopic in interface MessagingService

Parameters:

topicId - the topic to be deleted

Throws:

co.cask.cdap.api.messaging.TopicNotFoundException - if the topic doesn't exist

IOException - if failed to delete the topic

getTopic

public TopicMetadata getTopic(co.cask.cdap.proto.id.TopicId topicId)
                       throws co.cask.cdap.api.messaging.TopicNotFoundException,
                              IOException

Description copied from interface: MessagingService

Returns the metadata of the given topic.

Specified by:

getTopic in interface MessagingService

Parameters:

topicId - message topic

Returns:

the TopicMetadata of the given topic.

Throws:

co.cask.cdap.api.messaging.TopicNotFoundException - if the topic doesn't exist

IOException - if failed to retrieve topic metadata.

listTopics

public List<co.cask.cdap.proto.id.TopicId> listTopics(co.cask.cdap.proto.id.NamespaceId namespaceId)
                                               throws IOException

Description copied from interface: MessagingService

Returns the list of topics available under the given namespace.

Specified by:

listTopics in interface MessagingService

Parameters:

namespaceId - the namespace to list topics under it

Returns:

a List of TopicId.

Throws:

IOException - if failed to retrieve topics.

prepareFetch

public MessageFetcher prepareFetch(co.cask.cdap.proto.id.TopicId topicId)
                            throws co.cask.cdap.api.messaging.TopicNotFoundException,
                                   IOException

Description copied from interface: MessagingService

Prepares to fetch messages from the given topic.

Specified by:

prepareFetch in interface MessagingService

Parameters:

topicId - the topic to fetch message from

Returns:

a MessageFetcher for setting up parameters for fetching messages from the messaging system

Throws:

co.cask.cdap.api.messaging.TopicNotFoundException - if the topic doesn't exist

IOException - if failed to fetch messages

publish

@Nullable
public RollbackDetail publish(StoreRequest request)
                                 throws co.cask.cdap.api.messaging.TopicNotFoundException,
                                        IOException

Description copied from interface: MessagingService

Publishes a list of messages to the messaging system.

Specified by:

publish in interface MessagingService

Parameters:

request - the StoreRequest containing messages to be published

Returns:

if the store request is transactional, then returns a RollbackDetail containing information for rollback; otherwise null will be returned.

Throws:

co.cask.cdap.api.messaging.TopicNotFoundException - if the topic doesn't exist

IOException - if failed to publish messages

storePayload

public void storePayload(StoreRequest request)
                  throws co.cask.cdap.api.messaging.TopicNotFoundException,
                         IOException

Description copied from interface: MessagingService

Stores a list of messages to the messaging system. It is for long / distributed transactional publishing use case.

Specified by:

storePayload in interface MessagingService

Parameters:

request - the StoreRequest containing messages to be stored

Throws:

co.cask.cdap.api.messaging.TopicNotFoundException - if the topic doesn't exist

IOException - if failed to store messages

rollback

public void rollback(co.cask.cdap.proto.id.TopicId topicId,
                     RollbackDetail rollbackDetail)
              throws co.cask.cdap.api.messaging.TopicNotFoundException,
                     IOException

Description copied from interface: MessagingService

Rollbacks messages published to the given topic with the given transaction.

Specified by:

rollback in interface MessagingService

Parameters:

topicId - the topic where the messages were published under

rollbackDetail - the RollbackDetail as returned by the MessagingService.publish(StoreRequest) call, which contains information needed for the rollback

Throws:

co.cask.cdap.api.messaging.TopicNotFoundException - if the topic doesn't exist

IOException - if failed to rollback changes