public class RetrySimulator
extends java.lang.Object
RetrySimulator is a tool for exercising retry + backoff operations.
When calibrating a set of retry + backoff pairs, it is useful to know the behaviour
of the retry for various scenarios.
Things you may want to know:
- Does a 'maxInterval' of 5000 ms in my backoff even matter?
(This is often the case when retry counts are low -- so why set the max interval
at something that cannot be achieved?)
- What are the typical sleep durations for threads in a retry
- What was the longest sleep duration for any retry sequence
The simulator provides this information by executing a retry + backoff pair until failure
(that is all retries are exhausted). The information about each retry is provided
as part of the RetrySimulation.
Note that the impetus for this class was to expose the timings which are possible with
ExponentialRandomBackOffPolicy, which provides
random values and must be looked at over a series of trials.| Modifier and Type | Class and Description |
|---|---|
(package private) static class |
RetrySimulator.FailingRetryCallback |
(package private) static class |
RetrySimulator.FailingRetryException |
(package private) static class |
RetrySimulator.StealingSleeper |
| Modifier and Type | Field and Description |
|---|---|
private SleepingBackOffPolicy<?> |
backOffPolicy |
private RetryPolicy |
retryPolicy |
| Constructor and Description |
|---|
RetrySimulator(SleepingBackOffPolicy<?> backOffPolicy,
RetryPolicy retryPolicy) |
| Modifier and Type | Method and Description |
|---|---|
RetrySimulation |
executeSimulation(int numSimulations)
Execute the simulator for a give # of iterations.
|
java.util.List<java.lang.Long> |
executeSingleSimulation()
Execute a single simulation
|
private final SleepingBackOffPolicy<?> backOffPolicy
private final RetryPolicy retryPolicy
public RetrySimulator(SleepingBackOffPolicy<?> backOffPolicy, RetryPolicy retryPolicy)
public RetrySimulation executeSimulation(int numSimulations)
numSimulations - Number of simulations to runpublic java.util.List<java.lang.Long> executeSingleSimulation()