/*
* 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.server.remotetask;
import com.facebook.presto.execution.StateMachine;
import com.facebook.presto.execution.TaskId;
import com.facebook.presto.execution.TaskInfo;
import com.facebook.presto.execution.TaskStatus;
import com.google.common.util.concurrent.Futures;
import com.google.common.util.concurrent.ListenableFuture;
import io.airlift.concurrent.SetThreadName;
import io.airlift.http.client.FullJsonResponseHandler;
import io.airlift.http.client.HttpClient;
import io.airlift.http.client.HttpUriBuilder;
import io.airlift.http.client.Request;
import io.airlift.json.JsonCodec;
import io.airlift.units.Duration;
import javax.annotation.concurrent.GuardedBy;
import java.net.URI;
import java.util.concurrent.Executor;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.ScheduledFuture;
import java.util.concurrent.atomic.AtomicLong;
import java.util.function.Consumer;
import static com.google.common.net.HttpHeaders.CONTENT_TYPE;
import static com.google.common.net.MediaType.JSON_UTF_8;
import static io.airlift.http.client.FullJsonResponseHandler.createFullJsonResponseHandler;
import static io.airlift.http.client.HttpUriBuilder.uriBuilderFrom;
import static io.airlift.http.client.Request.Builder.prepareGet;
import static io.airlift.units.Duration.nanosSince;
import static java.util.Objects.requireNonNull;
import static java.util.concurrent.TimeUnit.MILLISECONDS;
public class TaskInfoFetcher
implements SimpleHttpResponseCallback<TaskInfo>
{
private final TaskId taskId;
private final Consumer<Throwable> onFail;
private final StateMachine<TaskInfo> taskInfo;
private final JsonCodec<TaskInfo> taskInfoCodec;
private final long updateIntervalMillis;
private final AtomicLong lastUpdateNanos = new AtomicLong();
private final ScheduledExecutorService updateScheduledExecutor;
private final Executor executor;
private final HttpClient httpClient;
private final RequestErrorTracker errorTracker;
private final boolean summarizeTaskInfo;
@GuardedBy("this")
private final AtomicLong currentRequestStartNanos = new AtomicLong();
private final RemoteTaskStats stats;
@GuardedBy("this")
private boolean running;
@GuardedBy("this")
private ScheduledFuture<?> scheduledFuture;
@GuardedBy("this")
private ListenableFuture<FullJsonResponseHandler.JsonResponse<TaskInfo>> future;
public TaskInfoFetcher(
Consumer<Throwable> onFail,
TaskInfo initialTask,
HttpClient httpClient,
Duration updateInterval,
JsonCodec<TaskInfo> taskInfoCodec,
Duration minErrorDuration,
Duration maxErrorDuration,
boolean summarizeTaskInfo,
Executor executor,
ScheduledExecutorService updateScheduledExecutor,
ScheduledExecutorService errorScheduledExecutor,
RemoteTaskStats stats)
{
requireNonNull(initialTask, "initialTask is null");
requireNonNull(minErrorDuration, "minErrorDuration is null");
requireNonNull(errorScheduledExecutor, "errorScheduledExecutor is null");
this.taskId = initialTask.getTaskStatus().getTaskId();
this.onFail = requireNonNull(onFail, "onFail is null");
this.taskInfo = new StateMachine<>("task " + taskId, executor, initialTask);
this.taskInfoCodec = requireNonNull(taskInfoCodec, "taskInfoCodec is null");
this.updateIntervalMillis = requireNonNull(updateInterval, "updateInterval is null").toMillis();
this.updateScheduledExecutor = requireNonNull(updateScheduledExecutor, "updateScheduledExecutor is null");
this.errorTracker = new RequestErrorTracker(taskId, initialTask.getTaskStatus().getSelf(), minErrorDuration, maxErrorDuration, errorScheduledExecutor, "getting info for task");
this.summarizeTaskInfo = summarizeTaskInfo;
this.executor = requireNonNull(executor, "executor is null");
this.httpClient = requireNonNull(httpClient, "httpClient is null");
this.stats = requireNonNull(stats, "stats is null");
}
public TaskInfo getTaskInfo()
{
return taskInfo.get();
}
public synchronized void start()
{
if (running) {
// already running
return;
}
running = true;
scheduleUpdate();
}
private synchronized void stop()
{
running = false;
if (future != null) {
future.cancel(true);
future = null;
}
if (scheduledFuture != null) {
scheduledFuture.cancel(true);
}
}
private synchronized void scheduleUpdate()
{
scheduledFuture = updateScheduledExecutor.scheduleWithFixedDelay(() -> {
synchronized (this) {
// if the previous request still running, don't schedule a new request
if (future != null && !future.isDone()) {
return;
}
}
if (nanosSince(lastUpdateNanos.get()).toMillis() >= updateIntervalMillis) {
sendNextRequest();
}
}, 0, 100, MILLISECONDS);
}
private synchronized void sendNextRequest()
{
TaskStatus taskStatus = getTaskInfo().getTaskStatus();
if (!running) {
return;
}
// we already have the final task info
if (isDone(getTaskInfo())) {
stop();
return;
}
// if we have an outstanding request
if (future != null && !future.isDone()) {
return;
}
// if throttled due to error, asynchronously wait for timeout and try again
ListenableFuture<?> errorRateLimit = errorTracker.acquireRequestPermit();
if (!errorRateLimit.isDone()) {
errorRateLimit.addListener(this::sendNextRequest, executor);
return;
}
HttpUriBuilder httpUriBuilder = uriBuilderFrom(taskStatus.getSelf());
URI uri = summarizeTaskInfo ? httpUriBuilder.addParameter("summarize").build() : httpUriBuilder.build();
Request request = prepareGet()
.setUri(uri)
.setHeader(CONTENT_TYPE, JSON_UTF_8.toString())
.build();
errorTracker.startRequest();
future = httpClient.executeAsync(request, createFullJsonResponseHandler(taskInfoCodec));
currentRequestStartNanos.set(System.nanoTime());
Futures.addCallback(future, new SimpleHttpResponseHandler<>(this, request.getUri(), stats), executor);
}
synchronized void updateTaskInfo(TaskInfo newValue)
{
boolean updated = taskInfo.setIf(newValue, oldValue -> {
TaskStatus oldTaskStatus = oldValue.getTaskStatus();
TaskStatus newTaskStatus = newValue.getTaskStatus();
if (oldTaskStatus.getState().isDone()) {
// never update if the task has reached a terminal state
return false;
}
// don't update to an older version (same version is ok)
return newTaskStatus.getVersion() >= oldTaskStatus.getVersion();
});
if (updated && newValue.getTaskStatus().getState().isDone()) {
stop();
}
}
@Override
public void success(TaskInfo newValue)
{
try (SetThreadName ignored = new SetThreadName("TaskInfoFetcher-%s", taskId)) {
lastUpdateNanos.set(System.nanoTime());
long startNanos;
synchronized (this) {
startNanos = this.currentRequestStartNanos.get();
}
updateStats(startNanos);
errorTracker.requestSucceeded();
updateTaskInfo(newValue);
}
}
@Override
public void failed(Throwable cause)
{
try (SetThreadName ignored = new SetThreadName("TaskInfoFetcher-%s", taskId)) {
lastUpdateNanos.set(System.nanoTime());
try {
// if task not already done, record error
if (!isDone(getTaskInfo())) {
errorTracker.requestFailed(cause);
}
}
catch (Error e) {
onFail.accept(e);
throw e;
}
catch (RuntimeException e) {
onFail.accept(e);
}
}
}
@Override
public void fatal(Throwable cause)
{
try (SetThreadName ignored = new SetThreadName("TaskInfoFetcher-%s", taskId)) {
onFail.accept(cause);
}
}
private void updateStats(long currentRequestStartNanos)
{
stats.infoRoundTripMillis(nanosSince(currentRequestStartNanos).toMillis());
}
private static boolean isDone(TaskInfo taskInfo)
{
return taskInfo.getTaskStatus().getState().isDone();
}
}