Package com.atlassian.bamboo.grpc

Class DeadLetterQueue

java.lang.Object

com.atlassian.bamboo.grpc.DeadLetterQueue

public class DeadLetterQueue
extends Object

This class is responsible for being the combination of dead letter queue and its monitor. The monitor is launched at the moment of object creation.

Instead of storing in the dead letter queue the whole events, we store actions. Single event could carry multiple actions. This was designed this way to handle partial failures, for example, a plan cache invalidation event carries multiple plan keys, each one of them triggering the invalidation action. If only one of the actions fails, we add this action to the dead letter queue instead of adding the whole event (with all its actions). As a result, we don't process multiple times the actions that have already been successfully processed before.

Since:

9.5

Field Summary

Fields

Modifier and Type	Field	Description
protected final LinkedBlockingQueue<Pair<Supplier<Runnable>,Integer>>	deadLetterQueue

Constructor Summary

Constructors

Constructor	Description
DeadLetterQueue()
DeadLetterQueue(int queueSize, int queueScanningIntervalSeconds, int maxRetriesNumber)

Method Summary

Modifier and Type	Method	Description
boolean	execute(Supplier<Runnable> toWrap, boolean handleByDeadLetterQueue)	Wraps the runnable with try-catch block and returns true if the runnable was executed successfully, otherwise returns false.
<T> Pair<Long,Long>	executeIfPresent(T item, Consumer<T> consumer, boolean handleByDeadLetterQueue)
<T> Pair<Long,Long>	executeIfPresentOnCollection(List<T> items, Consumer<T> consumer, boolean handleByDeadLetterQueue)
protected Runnable	getDeadLetterQueueMonitorJob()

Methods inherited from class java.lang.Object

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

Field Details

deadLetterQueue

@VisibleForTesting
protected final LinkedBlockingQueue<Pair<Supplier<Runnable>,Integer>> deadLetterQueue

Constructor Details

DeadLetterQueue

public DeadLetterQueue()

DeadLetterQueue

@VisibleForTesting
public DeadLetterQueue(int queueSize,
 int queueScanningIntervalSeconds,
 int maxRetriesNumber)

Method Details

getDeadLetterQueueMonitorJob

@VisibleForTesting
protected Runnable getDeadLetterQueueMonitorJob()

execute

public boolean execute(Supplier<Runnable> toWrap,
 boolean handleByDeadLetterQueue)

Wraps the runnable with try-catch block and returns true if the runnable was executed successfully, otherwise returns false.

executeIfPresentOnCollection

public <T> Pair<Long,Long> executeIfPresentOnCollection(List<T> items,
 Consumer<T> consumer,
 boolean handleByDeadLetterQueue)

Returns:

the pair with the first element being the number of successful executions and the second element being the number of failed executions

executeIfPresent

public <T> Pair<Long,Long> executeIfPresent(T item,
 Consumer<T> consumer,
 boolean handleByDeadLetterQueue)