org.apache.flink.runtime.rest.handler.job.checkpoints.AbstractCheckpointHandler Maven / Gradle / Ivy

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 * Licensed to the Apache Software Foundation (ASF) under one
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 * 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,
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 * See the License for the specific language governing permissions and
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 */

package org.apache.flink.runtime.rest.handler.job.checkpoints;

import org.apache.flink.api.common.time.Time;
import org.apache.flink.runtime.checkpoint.AbstractCheckpointStats;
import org.apache.flink.runtime.checkpoint.CheckpointStatsSnapshot;
import org.apache.flink.runtime.executiongraph.AccessExecutionGraph;
import org.apache.flink.runtime.rest.handler.HandlerRequest;
import org.apache.flink.runtime.rest.handler.RestHandlerException;
import org.apache.flink.runtime.rest.handler.job.AbstractExecutionGraphHandler;
import org.apache.flink.runtime.rest.handler.legacy.ExecutionGraphCache;
import org.apache.flink.runtime.rest.messages.EmptyRequestBody;
import org.apache.flink.runtime.rest.messages.MessageHeaders;
import org.apache.flink.runtime.rest.messages.ResponseBody;
import org.apache.flink.runtime.rest.messages.checkpoints.CheckpointIdPathParameter;
import org.apache.flink.runtime.rest.messages.checkpoints.CheckpointMessageParameters;
import org.apache.flink.runtime.webmonitor.RestfulGateway;
import org.apache.flink.runtime.webmonitor.retriever.GatewayRetriever;
import org.apache.flink.util.Preconditions;

import org.apache.flink.shaded.netty4.io.netty.handler.codec.http.HttpResponseStatus;

import java.util.Map;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.Executor;

/**
 * Base class for checkpoint related REST handler.
 *
 * @param  type of the response
 */
public abstract class AbstractCheckpointHandler extends AbstractExecutionGraphHandler {

	private final CheckpointStatsCache checkpointStatsCache;

	protected AbstractCheckpointHandler(
			CompletableFuture localRestAddress,
			GatewayRetriever leaderRetriever,
			Time timeout,
			Map responseHeaders,
			MessageHeaders messageHeaders,
			ExecutionGraphCache executionGraphCache,
			Executor executor,
			CheckpointStatsCache checkpointStatsCache) {
		super(localRestAddress, leaderRetriever, timeout, responseHeaders, messageHeaders, executionGraphCache, executor);

		this.checkpointStatsCache = Preconditions.checkNotNull(checkpointStatsCache);
	}

	@Override
	protected R handleRequest(HandlerRequest request, AccessExecutionGraph executionGraph) throws RestHandlerException {
		final long checkpointId = request.getPathParameter(CheckpointIdPathParameter.class);

		final CheckpointStatsSnapshot checkpointStatsSnapshot = executionGraph.getCheckpointStatsSnapshot();

		if (checkpointStatsSnapshot != null) {
			AbstractCheckpointStats checkpointStats = checkpointStatsSnapshot.getHistory().getCheckpointById(checkpointId);

			if (checkpointStats != null) {
				checkpointStatsCache.tryAdd(checkpointStats);
			} else {
				checkpointStats = checkpointStatsCache.tryGet(checkpointId);
			}

			if (checkpointStats != null) {
				return handleCheckpointRequest(request, checkpointStats);
			} else {
				throw new RestHandlerException("Could not find checkpointing statistics for checkpoint " + checkpointId + '.', HttpResponseStatus.NOT_FOUND);
			}
		} else {
			throw new RestHandlerException("Checkpointing was not enabled for job " + executionGraph.getJobID() + '.', HttpResponseStatus.NOT_FOUND);
		}
	}

	/**
	 * Called for each request with the corresponding {@link AbstractCheckpointStats} instance.
	 *
	 * @param request for further information
	 * @param checkpointStats for which the handler is called
	 * @return Response
	 * @throws RestHandlerException if the handler could not handle the request
	 */
	protected abstract R handleCheckpointRequest(HandlerRequest request, AbstractCheckpointStats checkpointStats) throws RestHandlerException;
}