com.linecorp.armeria.client.retry

Class RetryingClient<I extends Request,O extends Response>

java.lang.Object

com.linecorp.armeria.common.util.AbstractUnwrappable<Client<T_I,T_O>>

com.linecorp.armeria.client.DecoratingClient<I,O,I,O>

com.linecorp.armeria.client.SimpleDecoratingClient<I,O>

com.linecorp.armeria.client.retry.RetryingClient<I,O>

Type Parameters:

I - the Request type

O - the Response type

All Implemented Interfaces:

Client<I,O>, Unwrappable

Direct Known Subclasses:

RetryingHttpClient, RetryingRpcClient

public abstract class RetryingClient<I extends Request,O extends Response>
extends SimpleDecoratingClient<I,O>

A Client decorator that handles failures of remote invocation and retries requests.

Field Summary

Fields

Modifier and Type	Field and Description
static io.netty.util.AsciiString	ARMERIA_RETRY_COUNT The header which indicates the retry count of a Request.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	RetryingClient(Client<I,O> delegate, RetryStrategy retryStrategy, int maxTotalAttempts, long responseTimeoutMillisForEachAttempt) Creates a new instance that decorates the specified Client.
protected	RetryingClient(Client<I,O> delegate, RetryStrategyWithContent<O> retryStrategyWithContent, int maxTotalAttempts, long responseTimeoutMillisForEachAttempt) Creates a new instance that decorates the specified Client.

Method Summary

Modifier and Type	Method and Description
protected abstract O	doExecute(ClientRequestContext ctx, I req) Invoked by execute(ClientRequestContext, Request) after the deadline for response timeout is set.
O	execute(ClientRequestContext ctx, I req) Sends a Request to a remote Endpoint, as specified in ClientRequestContext.endpoint().
protected long	getNextDelay(ClientRequestContext ctx, Backoff backoff) Returns the next delay which retry will be made after.
protected long	getNextDelay(ClientRequestContext ctx, Backoff backoff, long millisAfterFromServer) Returns the next delay which retry will be made after.
protected static int	getTotalAttempts(ClientRequestContext ctx) Returns the total number of attempts of the current request represented by the specified ClientRequestContext.
protected static ClientRequestContext	newDerivedContext(ClientRequestContext ctx, HttpRequest req, RpcRequest rpcReq, boolean initialAttempt) Creates a new derived ClientRequestContext, replacing the requests.
protected static void	onRetryingComplete(ClientRequestContext ctx) This should be called when retrying is finished.
protected RetryStrategy	retryStrategy() Returns the RetryStrategy.
protected RetryStrategyWithContent<O>	retryStrategyWithContent() Returns the RetryStrategyWithContent.
protected static void	scheduleNextRetry(ClientRequestContext ctx, Consumer<? super Throwable> actionOnException, Runnable retryTask, long nextDelayMillis) Schedules next retry.
protected boolean	setResponseTimeout(ClientRequestContext ctx) Resets the ClientRequestContext.responseTimeoutMillis().

Methods inherited from class com.linecorp.armeria.common.util.AbstractUnwrappable

as, delegate, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface com.linecorp.armeria.client.Client

as

Field Detail

ARMERIA_RETRY_COUNT

public static final io.netty.util.AsciiString ARMERIA_RETRY_COUNT

The header which indicates the retry count of a Request. The server might use this value to reject excessive retries, etc.

Constructor Detail

RetryingClient

protected RetryingClient(Client<I,O> delegate,
                         RetryStrategy retryStrategy,
                         int maxTotalAttempts,
                         long responseTimeoutMillisForEachAttempt)

Creates a new instance that decorates the specified Client.

RetryingClient

protected RetryingClient(Client<I,O> delegate,
                         RetryStrategyWithContent<O> retryStrategyWithContent,
                         int maxTotalAttempts,
                         long responseTimeoutMillisForEachAttempt)

Creates a new instance that decorates the specified Client.

Method Detail

execute

public O execute(ClientRequestContext ctx,
                 I req)
          throws Exception

Description copied from interface: Client

Sends a Request to a remote Endpoint, as specified in ClientRequestContext.endpoint().

Returns:

the Response to the specified Request

Throws:

Exception

doExecute

protected abstract O doExecute(ClientRequestContext ctx,
                               I req)
                        throws Exception

Invoked by execute(ClientRequestContext, Request) after the deadline for response timeout is set.

Throws:

Exception

onRetryingComplete

protected static void onRetryingComplete(ClientRequestContext ctx)

This should be called when retrying is finished.

retryStrategy

protected RetryStrategy retryStrategy()

Returns the RetryStrategy.

Throws:

IllegalStateException - if the RetryStrategy is not set

retryStrategyWithContent

protected RetryStrategyWithContent<O> retryStrategyWithContent()

Returns the RetryStrategyWithContent.

Throws:

IllegalStateException - if the RetryStrategyWithContent is not set

scheduleNextRetry

protected static void scheduleNextRetry(ClientRequestContext ctx,
                                        Consumer<? super Throwable> actionOnException,
                                        Runnable retryTask,
                                        long nextDelayMillis)

Schedules next retry.

setResponseTimeout

protected final boolean setResponseTimeout(ClientRequestContext ctx)

Resets the ClientRequestContext.responseTimeoutMillis().

Returns:

true if the response timeout is set, false if it can't be set due to the timeout

getNextDelay

protected final long getNextDelay(ClientRequestContext ctx,
                                  Backoff backoff)

Returns the next delay which retry will be made after. The delay will be:

Math.min(responseTimeoutMillis, Backoff.nextDelayMillis(int))

Returns:

the number of milliseconds to wait for before attempting a retry. -1 if the currentAttemptNo exceeds the maxAttempts or the nextDelay is after the moment which timeout happens.

getNextDelay

protected final long getNextDelay(ClientRequestContext ctx,
                                  Backoff backoff,
                                  long millisAfterFromServer)

Returns the next delay which retry will be made after. The delay will be:

Math.min(responseTimeoutMillis, Math.max(Backoff.nextDelayMillis(int), millisAfterFromServer))

Returns:

the number of milliseconds to wait for before attempting a retry. -1 if the currentAttemptNo exceeds the maxAttempts or the nextDelay is after the moment which timeout happens.

getTotalAttempts

protected static int getTotalAttempts(ClientRequestContext ctx)

Returns the total number of attempts of the current request represented by the specified ClientRequestContext.

newDerivedContext

protected static ClientRequestContext newDerivedContext(ClientRequestContext ctx,
                                                        @Nullable
                                                        HttpRequest req,
                                                        @Nullable
                                                        RpcRequest rpcReq,
                                                        boolean initialAttempt)

Creates a new derived ClientRequestContext, replacing the requests. If ClientRequestContext.endpointSelector() exists, a new Endpoint will be selected.