com.solace.messaging.publisher

Interface PublisherHealthCheck

All Known Subinterfaces:

DirectMessagePublisher, MessagePublisher, PersistentMessagePublisher, RequestReplyMessagePublisher

@ProviderType
public interface PublisherHealthCheck

An interface for publisher readiness estimation.

Since:

1.0

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	PublisherHealthCheck.PublisherReadinessListener An interface that is abstraction for the handling of a publisher instance's ability to take new messages and send them over the wire to a remote broker.

Method Summary

Modifier and Type	Method and Description
boolean	isReady() A non-blocking check to determine if the publisher can potentially publish messages.
void	notifyWhenReady() A non-blocking request to notify PublisherHealthCheck.PublisherReadinessListener.
void	setPublisherReadinessListener(PublisherHealthCheck.PublisherReadinessListener listener) Sets a publisher readiness listener when supported, to be used with rejecting back pressure strategy.

Method Detail

isReady

boolean isReady()

A non-blocking check to determine if the publisher can potentially publish messages.

Returns:

false if nothing prevents publisher from sending messages including i.e., full buffer or I/O problems; true otherwise

Since:

1.0

notifyWhenReady

void notifyWhenReady()

A non-blocking request to notify PublisherHealthCheck.PublisherReadinessListener. This method can help to overcome a possible race condition that may occur between the completing the processing of an exception and publishing an event when in the READY state (i.e., when sending an event).

Example usage is demonstrated as follows:

   ...
   boolean exitExceptionally = false;
   try {
         messagePublisher.publish(message, toDestination);
       } catch (PublisherOverflowException overflowException) {
         // perform tasks in case of overflow
         exitExceptionally = true;
       } catch (PubSubPlusClientException exception) {
         // perform tasks based on exception
         // may call exitExceptionally = true;
       } finally {
         if (exitExceptionally) {
          // request a notification on
           messagePublisher.notifyWhenReady();
         }
       }
     

Since:

1.0

setPublisherReadinessListener

void setPublisherReadinessListener(PublisherHealthCheck.PublisherReadinessListener listener)

Sets a publisher readiness listener when supported, to be used with rejecting back pressure strategy.

Parameters:

listener - the listener to listen for publisher state changes

Since:

1.0