Package com.google.gerrit.server.update

Class RetryableAction<T>

java.lang.Object

com.google.gerrit.server.update.RetryableAction<T>

Direct Known Subclasses:

RetryableChangeAction, RetryableIndexQueryAction

public class RetryableAction<T>
extends Object

An action that is executed with retrying.

Instances of this class are created via RetryHelper (see RetryHelper.action(ActionType, String, Action), RetryHelper.accountUpdate(String, Action), RetryHelper.changeUpdate(String, Action), RetryHelper.groupUpdate(String, Action), RetryHelper.pluginUpdate(String, Action)).

Which exceptions cause a retry is controlled by ExceptionHook.shouldRetry(String, String, Throwable). In addition callers can specify additional exception that should cause a retry via retryOn(Predicate).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static interface	RetryableAction.Action<T>
static class	RetryableAction.ActionType	Type of an retryable action.

Method Summary

Modifier and Type	Method	Description
T	call()	Executes this action with retry.
RetryableAction<T>	defaultTimeoutMultiplier(int multiplier)	Increases the default timeout by the given multiplier.
RetryableAction<T>	listener(com.github.rholder.retry.RetryListener retryListener)	Sets a listener that is invoked when the action is retried.
RetryableAction<T>	onAutoTrace(Consumer<String> traceIdConsumer)	Sets a callback that is invoked when auto-retry with tracing is triggered.
RetryableAction<T>	retryOn(Predicate<Throwable> exceptionPredicate)	Adds an additional condition that should trigger retries.
RetryableAction<T>	retryWithTrace(Predicate<Throwable> exceptionPredicate)	Sets a condition that should trigger auto-retry with tracing.

Methods inherited from class java.lang.Object

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

Method Detail

retryOn

public RetryableAction<T> retryOn(Predicate<Throwable> exceptionPredicate)

Adds an additional condition that should trigger retries.

For some exceptions retrying is enabled globally (see ExceptionHook.shouldRetry(String, String, Throwable)). Conditions for those exceptions do not need to be specified here again.

This method can be invoked multiple times to add further conditions that should trigger retries.

Parameters:

exceptionPredicate - predicate that decides if the action should be retried for a given exception

Returns:

this instance to enable chaining of calls

retryWithTrace

public RetryableAction<T> retryWithTrace(Predicate<Throwable> exceptionPredicate)

Sets a condition that should trigger auto-retry with tracing.

This condition is only relevant if an exception occurs that doesn't trigger (normal) retry.

Auto-retry with tracing automatically captures traces for unexpected exceptions so that they can be investigated.

Every call of this method overwrites any previously set condition for auto-retry with tracing.

Parameters:

exceptionPredicate - predicate that decides if the action should be retried with tracing for a given exception

Returns:

this instance to enable chaining of calls

onAutoTrace

public RetryableAction<T> onAutoTrace(Consumer<String> traceIdConsumer)

Sets a callback that is invoked when auto-retry with tracing is triggered.

Via the callback callers can find out with trace ID was used for the retry.

Every call of this method overwrites any previously set trace ID consumer.

Parameters:

traceIdConsumer - trace ID consumer

Returns:

this instance to enable chaining of calls

listener

public RetryableAction<T> listener(com.github.rholder.retry.RetryListener retryListener)

Sets a listener that is invoked when the action is retried.

Every call of this method overwrites any previously set listener.

Parameters:

retryListener - retry listener

Returns:

this instance to enable chaining of calls

defaultTimeoutMultiplier

public RetryableAction<T> defaultTimeoutMultiplier(int multiplier)

Increases the default timeout by the given multiplier.

Every call of this method overwrites any previously set timeout.

Parameters:

multiplier - multiplier for the default timeout

Returns:

this instance to enable chaining of calls

call

public T call()
       throws Exception

Executes this action with retry.

Returns:

the result of the action

Throws:

Exception