Package org.apache.bookkeeper.common.util

Class Retries

java.lang.Object

org.apache.bookkeeper.common.util.Retries

public final class Retries
extends java.lang.Object

A util class for supporting retries with customized backoff.

Field Summary

Fields

Modifier and Type	Field	Description
static java.util.function.Predicate<java.lang.Throwable>	NonFatalPredicate

Method Summary

Modifier and Type	Method	Description
static <ReturnT> java.util.concurrent.CompletableFuture<ReturnT>	run(java.util.stream.Stream<java.lang.Long> backoffs, java.util.function.Predicate<java.lang.Throwable> retryPredicate, java.util.function.Supplier<java.util.concurrent.CompletableFuture<ReturnT>> task, OrderedScheduler scheduler)	Retry a given task on failures.
static <ReturnT> java.util.concurrent.CompletableFuture<ReturnT>	run(java.util.stream.Stream<java.lang.Long> backoffs, java.util.function.Predicate<java.lang.Throwable> retryPredicate, java.util.function.Supplier<java.util.concurrent.CompletableFuture<ReturnT>> task, OrderedScheduler scheduler, java.lang.Object key)	Retry a given task on failures.

Methods inherited from class java.lang.Object

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

Field Detail

NonFatalPredicate

public static final java.util.function.Predicate<java.lang.Throwable> NonFatalPredicate

Method Detail

run

public static <ReturnT> java.util.concurrent.CompletableFuture<ReturnT> run(java.util.stream.Stream<java.lang.Long> backoffs,
                                                                            java.util.function.Predicate<java.lang.Throwable> retryPredicate,
                                                                            java.util.function.Supplier<java.util.concurrent.CompletableFuture<ReturnT>> task,
                                                                            OrderedScheduler scheduler)

Retry a given task on failures.

It is a shortcut of run(Stream, Predicate, Supplier, OrderedScheduler, Object) that runs retries on any threads in the provided scheduler.

Type Parameters:

ReturnT - the return type

Parameters:

backoffs - a stream of backoff delays, in milliseconds.

retryPredicate - a predicate to test if failures are retryable.

task - a task to execute.

scheduler - scheduler to schedule the task and complete the futures.

Returns:

future represents the result of the task with retries.

run

public static <ReturnT> java.util.concurrent.CompletableFuture<ReturnT> run(java.util.stream.Stream<java.lang.Long> backoffs,
                                                                            java.util.function.Predicate<java.lang.Throwable> retryPredicate,
                                                                            java.util.function.Supplier<java.util.concurrent.CompletableFuture<ReturnT>> task,
                                                                            OrderedScheduler scheduler,
                                                                            java.lang.Object key)

Retry a given task on failures.

It will only retry the tasks when the predicate retryPredicate tests it as a retryable failure and it doesn't exhaust the retry budget. The retry delays are defined in a stream of delay values (in milliseconds).

If a schedule key is provided, the task will be submitted to the scheduler using the provided schedule key and also the returned future will be completed in the same thread. Otherwise, the task and the returned future will be executed and scheduled on any threads in the scheduler.

Type Parameters:

ReturnT - the return tye.

Parameters:

backoffs - a stream of backoff delays, in milliseconds.

retryPredicate - a predicate to test if failures are retryable.

task - a task to execute.

scheduler - scheduler to schedule the task and complete the futures.

key - the submit key for the scheduler.

Returns:

future represents the result of the task with retries.