org.keycloak.common.util

Class Retry

java.lang.Object

org.keycloak.common.util.Retry

public class Retry
extends Object

Author:

Stian Thorgersen

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	Retry.AdvancedRunnable Runnable, which provides some additional info (iteration for now)
static interface	Retry.Supplier<T> Needed here because: - java.util.function.Supplier defined from Java 8 - Adds some additional info (current iteration)
static interface	Retry.ThrowableCallback Needed here because: - java.util.function.BiConsumer defined from Java 8 - Adds some additional info (current iteration and called throwable

Constructor Summary

Constructors

Constructor and Description
Retry()

Method Summary

Modifier and Type	Method and Description
static <T> T	call(Retry.Supplier<T> supplier, int attemptsCount, long intervalMillis) Runs the given runnable at most attemptsCount times until it passes, leaving intervalMillis milliseconds between the invocations.
static int	execute(Runnable runnable, int attemptsCount, long intervalMillis) Runs the given runnable at most attemptsCount times until it passes, leaving intervalMillis milliseconds between the invocations.
static int	executeWithBackoff(Retry.AdvancedRunnable runnable, int attemptsCount, int intervalBaseMillis) Runs the given runnable at most attemptsCount times until it passes, leaving some increasing random delay milliseconds between the invocations.
static int	executeWithBackoff(Retry.AdvancedRunnable runnable, Retry.ThrowableCallback throwableCallback, int attemptsCount, int intervalBaseMillis)

Methods inherited from class java.lang.Object

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

Constructor Detail

Retry

public Retry()

Method Detail

execute

public static int execute(Runnable runnable,
                          int attemptsCount,
                          long intervalMillis)

Runs the given runnable at most attemptsCount times until it passes, leaving intervalMillis milliseconds between the invocations. The runnable is reexecuted if it throws a RuntimeException or AssertionError.

Parameters:

runnable -

attemptsCount - Total number of attempts to execute the runnable

intervalMillis -

Returns:

Index of the first successful invocation, starting from 0.

executeWithBackoff

public static int executeWithBackoff(Retry.AdvancedRunnable runnable,
                                     int attemptsCount,
                                     int intervalBaseMillis)

Runs the given runnable at most attemptsCount times until it passes, leaving some increasing random delay milliseconds between the invocations. It uses Exponential backoff + jitter algorithm to compute the delay. More details https://aws.amazon.com/blogs/architecture/exponential-backoff-and-jitter/ The base for delay is specified by intervalBaseMillis number. The runnable is reexecuted if it throws a RuntimeException or AssertionError.

Parameters:

runnable -

attemptsCount - Total number of attempts to execute the runnable

intervalBaseMillis - base for the exponential backoff + jitter

Returns:

Index of the first successful invocation, starting from 0.

executeWithBackoff

public static int executeWithBackoff(Retry.AdvancedRunnable runnable,
                                     Retry.ThrowableCallback throwableCallback,
                                     int attemptsCount,
                                     int intervalBaseMillis)

call

public static <T> T call(Retry.Supplier<T> supplier,
                         int attemptsCount,
                         long intervalMillis)

Runs the given runnable at most attemptsCount times until it passes, leaving intervalMillis milliseconds between the invocations. The runnable is reexecuted if it throws a RuntimeException or AssertionError.

Parameters:

supplier -

attemptsCount - Total number of attempts to execute the runnable

intervalMillis -

Returns:

Value generated by the supplier.