io.picodata.driver.api.retry

Interface RequestRetryPolicy

All Known Implementing Classes:

TarantoolRequestRetryPolicies.AttemptsBoundRetryPolicy, TarantoolRequestRetryPolicies.InfiniteRetryPolicy

Functional Interface:

This is a functional interface and can therefore be used as the assignment target for a lambda expression or method reference.

@FunctionalInterface
public interface RequestRetryPolicy

Request retry policy contains an algorithm of deciding whether an exception is retryable and settings for limiting the retry attempts

Field Summary

Fields

Modifier and Type	Field and Description
static int	DEFAULT_DELAY
static long	DEFAULT_REQUEST_TIMEOUT

Method Summary

Modifier and Type	Method and Description
boolean	canRetryRequest(Throwable throwable) A callback called when the request ends with an exception.
default long	getDelay() Delay that is used to wait before start attempt again.
default Throwable	getPolicyException(Throwable ex) Get an exception stating why the policy cannot repeat the request
default long	getRequestTimeout() Get timeout value for one retry attempt.
default <T> CompletableFuture<T>	wrapOperation(Supplier<CompletableFuture<T>> operation, Executor executor) Wrap a generic operation taking an arbitrary number of arguments and returning a CompletableFuture.

Field Detail

DEFAULT_DELAY

static final int DEFAULT_DELAY

See Also:

Constant Field Values

DEFAULT_REQUEST_TIMEOUT

static final long DEFAULT_REQUEST_TIMEOUT

Method Detail

canRetryRequest

boolean canRetryRequest(Throwable throwable)

A callback called when the request ends with an exception. Should return true if and only if the request may be performed again (e.g. it is a timeout exception and it indicates only that the current server is overloaded). This may depend not only on the exception type, but also on the other conditions like the allowed number of retries or the maximum request execution time.

Effective use of the retry policies may be achieved by combining them with multiple server connections and a ConnectionSelectionStrategy.

Parameters:

throwable - exception a request failed with

Returns:

true if the request may be retried

getRequestTimeout

default long getRequestTimeout()

Get timeout value for one retry attempt. The default value is 1 hour.

Returns:

timeout value (ms), should be greater or equal to 0

getDelay

default long getDelay()

Delay that is used to wait before start attempt again.

Returns:

get delay between retrying attempts

getPolicyException

default Throwable getPolicyException(Throwable ex)

Get an exception stating why the policy cannot repeat the request

Parameters:

ex - exception that will be wrapped

Returns:

reason of stopping retrying

wrapOperation

default <T> CompletableFuture<T> wrapOperation(Supplier<CompletableFuture<T>> operation,
                                               Executor executor)

Wrap a generic operation taking an arbitrary number of arguments and returning a CompletableFuture.

Type Parameters:

T - operation result type

Parameters:

operation - supplier for the operation to perform. Must return a new operation instance

executor - executor in which the retry callbacks will be scheduled

Returns:

CompletableFuture with the same type as the operation result type