com.netflix.conductor.common.utils

Class RetryUtil<T>

java.lang.Object

com.netflix.conductor.common.utils.RetryUtil<T>

Type Parameters:

T - The type of the object that will be returned by the flaky supplier function

public class RetryUtil<T>
extends java.lang.Object

Utility class that deals with retries in case of transient failures. Note: Create a new RetryUtil for every operation that needs to retried for the stated retries. Limitations:

• The current implementation does not make a distinction between transient and non transient errors. There is no categorization of transient and non transient failure in Conductor. Once the exception hierarchy is available in Conductor, this class implementation can be changed to short circuit the non transient errors.
• Currently only couple of wait strategies are implemented WaitStrategies.exponentialWait() and WaitStrategies.randomWait(long, TimeUnit) with fixed attributes for each of the strategies.
• The retry limit is not configurable and is hard coded to 3

Constructor Summary

Constructors

Constructor and Description
RetryUtil()

Method Summary

Modifier and Type	Method and Description
T	retryOnException(java.util.function.Supplier<T> supplierCommand, com.google.common.base.Predicate<java.lang.Throwable> throwablePredicate, com.google.common.base.Predicate<T> resultRetryPredicate, int retryCount, java.lang.String shortDescription, java.lang.String operationName) A helper method which has the ability to execute a flaky supplier function and retry in case of failures.

Methods inherited from class java.lang.Object

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

Constructor Detail

RetryUtil

public RetryUtil()

Method Detail

retryOnException

public T retryOnException(java.util.function.Supplier<T> supplierCommand,
                          com.google.common.base.Predicate<java.lang.Throwable> throwablePredicate,
                          com.google.common.base.Predicate<T> resultRetryPredicate,
                          int retryCount,
                          java.lang.String shortDescription,
                          java.lang.String operationName)
                   throws java.lang.RuntimeException

A helper method which has the ability to execute a flaky supplier function and retry in case of failures.

Parameters:

supplierCommand: - Any function that is flaky and needs multiple retries.

throwablePredicate: - A Guava Predicate housing the exceptional criteria to perform informed filtering before retrying.

resultRetryPredicate: - a predicate to be evaluated for a valid condition of the expected result

retryCount: - Number of times the function is to be retried before failure

shortDescription: - A short description of the function that will be used in logging and error propagation. The intention of this description is to provide context for Operability.

operationName: - The name of the function for traceability in logs

Returns:

an instance of return type of the supplierCommand

Throws:

java.lang.RuntimeException - in case of failed attempts to get T, which needs to be returned by the supplierCommand. The instance of the returned exception has:

• A message with shortDescription and operationName with the number of retries made
• And a reference to the original exception generated during the last Attempt of the retry