org.apache.gobblin.util.request_allocation.PriorityIterableBasedRequestAllocator.java Source code

Introduction

Here is the source code for org.apache.gobblin.util.request_allocation.PriorityIterableBasedRequestAllocator.java

Source

/*
 * 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.gobblin.util.request_allocation;

import java.util.Iterator;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;

import lombok.AccessLevel;
import lombok.Getter;

import org.slf4j.Logger;

import com.google.common.base.Function;
import com.google.common.base.Optional;
import com.google.common.collect.Iterators;

import org.apache.gobblin.util.Either;
import org.apache.gobblin.util.ExecutorsUtils;
import org.apache.gobblin.util.executors.IteratorExecutor;

public abstract class PriorityIterableBasedRequestAllocator<T extends Request<T>> implements RequestAllocator<T> {

    private final Logger log;
    @Getter(value = AccessLevel.PROTECTED)
    private final RequestAllocatorConfig<T> configuration;

    //These are for submitting alertable events
    @Getter
    private List<T> requestsExceedingAvailableResourcePool;
    @Getter
    private List<T> requestsRejectedWithLowPriority;
    @Getter
    private List<T> requestsRejectedDueToInsufficientEviction;
    @Getter
    private List<T> requestsDropped;

    public PriorityIterableBasedRequestAllocator(Logger log, RequestAllocatorConfig<T> configuration) {
        this.log = log;
        this.configuration = configuration;
    }

    @Override
    public AllocatedRequestsIterator<T> allocateRequests(Iterator<? extends Requestor<T>> requestors,
            ResourcePool resourcePool) {
        final ConcurrentBoundedPriorityIterable<T> iterable = new ConcurrentBoundedPriorityIterable<>(
                this.configuration.getPrioritizer(), this.configuration.getResourceEstimator(),
                this.configuration.getStoreRejectedRequestsSetting(), resourcePool);

        final Iterator<T> joinIterator = getJoinIterator(requestors, iterable);

        if (this.configuration.getAllowedThreads() <= 1) {
            while (joinIterator.hasNext()) {
                iterable.add(joinIterator.next());
            }
        } else {

            IteratorExecutor<Void> executor = new IteratorExecutor<>(
                    Iterators.transform(joinIterator, new Function<T, Callable<Void>>() {
                        @Override
                        public Callable<Void> apply(final T input) {
                            return new Callable<Void>() {
                                @Override
                                public Void call() throws Exception {
                                    iterable.add(input);
                                    return null;
                                }
                            };
                        }
                    }), this.configuration.getAllowedThreads(),
                    ExecutorsUtils.newThreadFactory(Optional.of(log), Optional.of("request-allocator-%d")));

            try {
                List<Either<Void, ExecutionException>> results = executor.executeAndGetResults();
                IteratorExecutor.logFailures(results, log, 10);
            } catch (InterruptedException ie) {
                log.error("Request allocation was interrupted.");
                return new AllocatedRequestsIteratorBase<>(
                        Iterators.<AllocatedRequestsIteratorBase.RequestWithResourceRequirement<T>>emptyIterator(),
                        resourcePool);
            }
        }

        iterable.logStatistics(Optional.of(this.log));

        //Get all requests rejected/dropped
        getRejectedAndDroppedRequests(iterable);

        return new AllocatedRequestsIteratorBase<>(iterable.iterator(), resourcePool);
    }

    public void getRejectedAndDroppedRequests(ConcurrentBoundedPriorityIterable<T> iterable) {
        requestsExceedingAvailableResourcePool = iterable.getRequestsExceedingAvailableResourcePool();
        requestsRejectedWithLowPriority = iterable.getRequestsRejectedWithLowPriority();
        requestsRejectedDueToInsufficientEviction = iterable.getRequestsRejectedDueToInsufficientEviction();
        requestsDropped = iterable.getRequestsDropped();
    }

    protected abstract Iterator<T> getJoinIterator(Iterator<? extends Requestor<T>> requestors,
            ConcurrentBoundedPriorityIterable<T> requestIterable);
}