Package org.apache.druid.messages.server

Class MessageRelayResource<MessageType>

java.lang.Object

org.apache.druid.messages.server.MessageRelayResource<MessageType>

public class MessageRelayResource<MessageType>
extends Object

Server-side resource for message relaying. Wraps an Outbox and MessageListener. The client for this resource is MessageRelayClient.

Constructor Summary

Constructors

Constructor	Description
MessageRelayResource(Outbox<MessageType> outbox, com.fasterxml.jackson.databind.ObjectMapper smileMapper, Class<MessageType> messageClass)

Method Summary

Modifier and Type	Method	Description
Void	httpGetMessagesFromOutbox(String clientHost, Long epoch, Long watermark, javax.servlet.http.HttpServletRequest req)	Retrieve messages from the outbox for a particular client, as a MessageBatch in Smile format.

Methods inherited from class java.lang.Object

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

Constructor Details

MessageRelayResource

public MessageRelayResource(Outbox<MessageType> outbox,
 com.fasterxml.jackson.databind.ObjectMapper smileMapper,
 Class<MessageType> messageClass)

Method Details

httpGetMessagesFromOutbox

public Void httpGetMessagesFromOutbox(String clientHost,
 Long epoch,
 Long watermark,
 @Context
 javax.servlet.http.HttpServletRequest req)
                               throws IOException

Retrieve messages from the outbox for a particular client, as a MessageBatch in Smile format. The messages are retrieved from Outbox.getMessages(String, long, long). This is a long-polling async method, using AsyncContext to wait up to GET_MESSAGES_TIMEOUT for messages to appear in the outbox.

Returns:

HTTP 200 with Smile response with messages on success; HTTP 204 (No Content) if no messages were put in the outbox before the timeout GET_MESSAGES_TIMEOUT elapsed

Throws:

IOException

See Also:

• for more details on the API