Many resources are needed to download a project. Please understand that we have to compensate our server costs. Thank you in advance. Project price only 1 $
You can buy this project and download/modify it how often you want.
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you under the Apache License, Version 2.0 (the
* "License"); you may not use this file except in compliance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.flink.runtime.rest.handler;
import org.apache.flink.api.common.time.Time;
import org.apache.flink.runtime.rest.handler.util.HandlerRedirectUtils;
import org.apache.flink.runtime.rest.handler.util.HandlerUtils;
import org.apache.flink.runtime.rest.messages.ErrorResponseBody;
import org.apache.flink.runtime.webmonitor.RestfulGateway;
import org.apache.flink.runtime.webmonitor.retriever.GatewayRetriever;
import org.apache.flink.util.OptionalConsumer;
import org.apache.flink.util.Preconditions;
import org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandler;
import org.apache.flink.shaded.netty4.io.netty.channel.ChannelHandlerContext;
import org.apache.flink.shaded.netty4.io.netty.channel.SimpleChannelInboundHandler;
import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponse;
import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponseStatus;
import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.router.KeepAliveWrite;
import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.router.Routed;
import org.apache.flink.shaded.netty4.io.netty.util.ReferenceCountUtil;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.annotation.Nonnull;
import java.util.Map;
import java.util.Optional;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.TimeUnit;
/**
* {@link SimpleChannelInboundHandler} which encapsulates the redirection logic for the
* REST endpoints.
*
* @param type of the leader to retrieve
*/
@ChannelHandler.Sharable
public abstract class RedirectHandler extends SimpleChannelInboundHandler {
protected final Logger logger = LoggerFactory.getLogger(getClass());
protected final CompletableFuture localAddressFuture;
protected final GatewayRetriever leaderRetriever;
protected final Time timeout;
protected final Map responseHeaders;
private String localAddress;
protected RedirectHandler(
@Nonnull CompletableFuture localAddressFuture,
@Nonnull GatewayRetriever leaderRetriever,
@Nonnull Time timeout,
@Nonnull Map responseHeaders) {
this.localAddressFuture = Preconditions.checkNotNull(localAddressFuture);
this.leaderRetriever = Preconditions.checkNotNull(leaderRetriever);
this.timeout = Preconditions.checkNotNull(timeout);
this.responseHeaders = Preconditions.checkNotNull(responseHeaders);
localAddress = null;
}
@Override
protected void channelRead0(
ChannelHandlerContext channelHandlerContext,
Routed routed) throws Exception {
if (localAddressFuture.isDone()) {
if (localAddress == null) {
try {
localAddress = localAddressFuture.get(timeout.toMilliseconds(), TimeUnit.MILLISECONDS);
} catch (Exception e) {
logger.error("Could not obtain local address.", e);
HandlerUtils.sendErrorResponse(
channelHandlerContext,
routed.request(),
new ErrorResponseBody("Fatal error. Could not obtain local address. Please try to refresh."),
HttpResponseStatus.INTERNAL_SERVER_ERROR,
responseHeaders);
return;
}
}
try {
OptionalConsumer optLeaderConsumer = OptionalConsumer.of(leaderRetriever.getNow());
optLeaderConsumer.ifPresent(
gateway -> {
CompletableFuture> optRedirectAddressFuture = HandlerRedirectUtils.getRedirectAddress(
localAddress,
gateway,
timeout);
// retain the message for the asynchronous handler
ReferenceCountUtil.retain(routed);
optRedirectAddressFuture.whenCompleteAsync(
(Optional optRedirectAddress, Throwable throwable) -> {
HttpResponse response;
try {
if (throwable != null) {
logger.error("Could not retrieve the redirect address.", throwable);
HandlerUtils.sendErrorResponse(
channelHandlerContext,
routed.request(),
new ErrorResponseBody("Could not retrieve the redirect address of the current leader. Please try to refresh."),
HttpResponseStatus.INTERNAL_SERVER_ERROR,
responseHeaders);
} else if (optRedirectAddress.isPresent()) {
response = HandlerRedirectUtils.getRedirectResponse(
optRedirectAddress.get(),
routed.path());
KeepAliveWrite.flush(channelHandlerContext, routed.request(), response);
} else {
try {
respondAsLeader(channelHandlerContext, routed, gateway);
} catch (Exception e) {
logger.error("Error while responding as leader.", e);
HandlerUtils.sendErrorResponse(
channelHandlerContext,
routed.request(),
new ErrorResponseBody("Error while responding to the request."),
HttpResponseStatus.INTERNAL_SERVER_ERROR,
responseHeaders);
}
}
} finally {
// release the message after processing it asynchronously
ReferenceCountUtil.release(routed);
}
}
, channelHandlerContext.executor());
}
).ifNotPresent(
() ->
HandlerUtils.sendErrorResponse(
channelHandlerContext,
routed.request(),
new ErrorResponseBody("Service temporarily unavailable due to an ongoing leader election. Please refresh."),
HttpResponseStatus.SERVICE_UNAVAILABLE,
responseHeaders));
} catch (Throwable throwable) {
logger.warn("Error occurred while processing web request.", throwable);
HandlerUtils.sendErrorResponse(
channelHandlerContext,
routed.request(),
new ErrorResponseBody("Error occurred in RedirectHandler: " + throwable.getMessage() + '.'),
HttpResponseStatus.INTERNAL_SERVER_ERROR,
responseHeaders);
}
} else {
HandlerUtils.sendErrorResponse(
channelHandlerContext,
routed.request(),
new ErrorResponseBody("Local address has not been resolved. This indicates an internal error."),
HttpResponseStatus.INTERNAL_SERVER_ERROR,
responseHeaders);
}
}
protected abstract void respondAsLeader(ChannelHandlerContext channelHandlerContext, Routed routed, T gateway) throws Exception;
}
