com.facebook.presto.execution.ClusterSizeMonitor.java Source code

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Here is the source code for com.facebook.presto.execution.ClusterSizeMonitor.java

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/*
 * Licensed 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 com.facebook.presto.execution;

import com.facebook.presto.execution.scheduler.NodeSchedulerConfig;
import com.facebook.presto.metadata.AllNodes;
import com.facebook.presto.metadata.InternalNodeManager;
import com.facebook.presto.spi.PrestoException;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Sets;
import com.google.common.util.concurrent.ListenableFuture;
import com.google.common.util.concurrent.SettableFuture;
import io.airlift.units.Duration;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.annotation.concurrent.GuardedBy;
import javax.inject.Inject;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.function.Consumer;

import static com.facebook.presto.spi.StandardErrorCode.GENERIC_INSUFFICIENT_RESOURCES;
import static com.facebook.presto.spi.StandardErrorCode.SERVER_STARTING_UP;
import static com.google.common.base.Preconditions.checkArgument;
import static com.google.common.util.concurrent.Futures.immediateFuture;
import static io.airlift.concurrent.Threads.threadsNamed;
import static io.airlift.units.Duration.nanosSince;
import static java.lang.String.format;
import static java.util.Objects.requireNonNull;
import static java.util.concurrent.Executors.newSingleThreadScheduledExecutor;
import static java.util.concurrent.TimeUnit.MILLISECONDS;

public class ClusterSizeMonitor {
    private final InternalNodeManager nodeManager;
    private final boolean includeCoordinator;
    private final int initializationMinCount;
    private final Duration initializationMaxWait;
    private final int executionMinCount;
    private final Duration executionMaxWait;
    private final ScheduledExecutorService executor;

    private final long createNanos = System.nanoTime();

    private final Consumer<AllNodes> listener = this::updateAllNodes;

    @GuardedBy("this")
    private int currentCount;

    @GuardedBy("this")
    private final List<SettableFuture<?>> futures = new ArrayList<>();

    @GuardedBy("this")
    private boolean minimumWorkerRequirementMet;

    @Inject
    public ClusterSizeMonitor(InternalNodeManager nodeManager, NodeSchedulerConfig nodeSchedulerConfig,
            QueryManagerConfig queryManagerConfig) {
        this(nodeManager, requireNonNull(nodeSchedulerConfig, "nodeSchedulerConfig is null").isIncludeCoordinator(),
                requireNonNull(queryManagerConfig, "queryManagerConfig is null").getInitializationRequiredWorkers(),
                queryManagerConfig.getInitializationTimeout(), queryManagerConfig.getRequiredWorkers(),
                queryManagerConfig.getRequiredWorkersMaxWait());
    }

    public ClusterSizeMonitor(InternalNodeManager nodeManager, boolean includeCoordinator,
            int initializationMinCount, Duration initializationMaxWait, int executionMinCount,
            Duration executionMaxWait) {
        this.nodeManager = requireNonNull(nodeManager, "nodeManager is null");
        this.includeCoordinator = includeCoordinator;
        checkArgument(initializationMinCount >= 0, "initializationMinCount is negative");
        this.initializationMinCount = initializationMinCount;
        this.initializationMaxWait = requireNonNull(initializationMaxWait, "initializationMaxWait is null");
        checkArgument(executionMinCount >= 0, "executionMinCount is negative");
        this.executionMinCount = executionMinCount;
        this.executionMaxWait = requireNonNull(executionMaxWait, "executionMaxWait is null");
        this.executor = newSingleThreadScheduledExecutor(threadsNamed("node-monitor-%s"));
    }

    @PostConstruct
    public void start() {
        nodeManager.addNodeChangeListener(listener);
        updateAllNodes(nodeManager.getAllNodes());
    }

    @PreDestroy
    public void stop() {
        nodeManager.removeNodeChangeListener(listener);
    }

    public synchronized void verifyInitialMinimumWorkersRequirement() {
        if (minimumWorkerRequirementMet) {
            return;
        }

        if (currentCount < initializationMinCount && nanosSince(createNanos).compareTo(initializationMaxWait) < 0) {
            throw new PrestoException(SERVER_STARTING_UP, format(
                    "Cluster is still initializing, there are insufficient active worker nodes (%s) to run query",
                    currentCount));
        }
        minimumWorkerRequirementMet = true;
    }

    public synchronized ListenableFuture<?> waitForMinimumWorkers() {
        if (currentCount >= executionMinCount) {
            return immediateFuture(null);
        }

        SettableFuture<?> future = SettableFuture.create();
        futures.add(future);

        // if future does not finish in wait period, complete with an exception
        ScheduledFuture<?> timeoutTask = executor.schedule(() -> {
            synchronized (this) {
                future.setException(new PrestoException(GENERIC_INSUFFICIENT_RESOURCES, format(
                        "Insufficient active worker nodes. Waited %s for at least %s workers, but only %s workers are active",
                        executionMaxWait, executionMinCount, currentCount)));
            }
        }, executionMaxWait.toMillis(), MILLISECONDS);

        // remove future if finished (e.g., canceled, timed out)
        future.addListener(() -> {
            timeoutTask.cancel(true);
            removeFuture(future);
        }, executor);

        return future;
    }

    private synchronized void removeFuture(SettableFuture<?> future) {
        futures.remove(future);
    }

    private synchronized void updateAllNodes(AllNodes allNodes) {
        if (includeCoordinator) {
            currentCount = allNodes.getActiveNodes().size();
        } else {
            currentCount = Sets.difference(allNodes.getActiveNodes(), allNodes.getActiveCoordinators()).size();
        }
        if (currentCount >= executionMinCount) {
            ImmutableList<SettableFuture<?>> listeners = ImmutableList.copyOf(futures);
            futures.clear();
            executor.submit(() -> listeners.forEach(listener -> listener.set(null)));
        }
    }
}