com.linecorp.armeria.client.retry

Interface RetryStrategy

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 RetryStrategy

Determines whether a failed request should be retried. If you need to determine by looking into the Response, use RetryStrategyWithContent.

Field Summary

Fields

Modifier and Type	Field and Description
static Backoff	defaultBackoff Deprecated. Use Backoff.ofDefault().

Method Summary

Modifier and Type	Method and Description
static RetryStrategy	never() A RetryStrategy that defines a retry should not be performed.
static RetryStrategy	onServerErrorStatus() Returns the RetryStrategy that retries the request with the Backoff.ofDefault() when the response status matches HttpStatusClass.SERVER_ERROR or an Exception is raised.
static RetryStrategy	onServerErrorStatus(Backoff backoff) Returns the RetryStrategy that retries the request with the specified backoff when the response status matches HttpStatusClass.SERVER_ERROR or an Exception is raised.
static RetryStrategy	onStatus(BiFunction<HttpStatus,Throwable,Backoff> backoffFunction) Returns the RetryStrategy that decides to retry the request using the specified backoffFunction.
static RetryStrategy	onUnprocessed() A RetryStrategy that retries only on UnprocessedRequestException with the Backoff.ofDefault().
static RetryStrategy	onUnprocessed(Backoff backoff) A RetryStrategy that retries only on UnprocessedRequestException with the specified Backoff.
CompletionStage<Backoff>	shouldRetry(ClientRequestContext ctx, Throwable cause) Tells whether the request sent with the specified ClientRequestContext requires a retry or not.

Field Detail

defaultBackoff

@Deprecated
static final Backoff defaultBackoff

Deprecated. Use Backoff.ofDefault().

The default Backoff implementation.

Method Detail

never

static RetryStrategy never()

A RetryStrategy that defines a retry should not be performed.

onUnprocessed

static RetryStrategy onUnprocessed()

A RetryStrategy that retries only on UnprocessedRequestException with the Backoff.ofDefault().

onUnprocessed

static RetryStrategy onUnprocessed(Backoff backoff)

A RetryStrategy that retries only on UnprocessedRequestException with the specified Backoff.

onServerErrorStatus

static RetryStrategy onServerErrorStatus()

Returns the RetryStrategy that retries the request with the Backoff.ofDefault() when the response status matches HttpStatusClass.SERVER_ERROR or an Exception is raised.

onServerErrorStatus

static RetryStrategy onServerErrorStatus(Backoff backoff)

Returns the RetryStrategy that retries the request with the specified backoff when the response status matches HttpStatusClass.SERVER_ERROR or an Exception is raised.

onStatus

static RetryStrategy onStatus(BiFunction<HttpStatus,Throwable,Backoff> backoffFunction)

Returns the RetryStrategy that decides to retry the request using the specified backoffFunction.

Parameters:

backoffFunction - the BiFunction that returns the Backoff or null according to the HttpStatus and Throwable

shouldRetry

CompletionStage<Backoff> shouldRetry(ClientRequestContext ctx,
                                     Throwable cause)

Tells whether the request sent with the specified ClientRequestContext requires a retry or not. Implement this method to return a CompletionStage and to complete it with a desired Backoff. To stop trying further, complete it with null.

To retrieve the ResponseHeaders, you can use the specified ClientRequestContext:

 CompletionStage<Backoff> shouldRetry(ClientRequestContext ctx, @Nullable Throwable cause) {
     if (cause != null) {
         return CompletableFuture.completedFuture(backoff);
     }

     ResponseHeaders responseHeaders = ctx.log().responseHeaders();
     if (responseHeaders.status().codeClass() == HttpStatusClass.SERVER_ERROR) {
         return CompletableFuture.completedFuture(backoff);
     }
     ...
 }
 

Parameters:

ctx - the ClientRequestContext of this request

cause - the Throwable which is raised while sending a request. null it there's no exception.