org.opensearch.tasks.TaskManager Maven / Gradle / Ivy
/*
* SPDX-License-Identifier: Apache-2.0
*
* The OpenSearch Contributors require contributions made to
* this file be licensed under the Apache-2.0 license or a
* compatible open source license.
*/
/*
* Licensed to Elasticsearch under one or more contributor
* license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright
* ownership. Elasticsearch 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.
*/
/*
* Modifications Copyright OpenSearch Contributors. See
* GitHub history for details.
*/
package org.opensearch.tasks;
import com.carrotsearch.hppc.ObjectIntHashMap;
import com.carrotsearch.hppc.ObjectIntMap;
import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.message.ParameterizedMessage;
import org.apache.lucene.util.SetOnce;
import org.opensearch.Assertions;
import org.opensearch.ExceptionsHelper;
import org.opensearch.OpenSearchException;
import org.opensearch.OpenSearchTimeoutException;
import org.opensearch.action.ActionListener;
import org.opensearch.action.ActionResponse;
import org.opensearch.cluster.ClusterChangedEvent;
import org.opensearch.cluster.ClusterStateApplier;
import org.opensearch.cluster.node.DiscoveryNode;
import org.opensearch.cluster.node.DiscoveryNodes;
import org.opensearch.common.lease.Releasable;
import org.opensearch.common.lease.Releasables;
import org.opensearch.common.settings.Settings;
import org.opensearch.common.unit.ByteSizeValue;
import org.opensearch.common.unit.TimeValue;
import org.opensearch.common.util.concurrent.AbstractRunnable;
import org.opensearch.common.util.concurrent.ConcurrentCollections;
import org.opensearch.common.util.concurrent.ConcurrentMapLong;
import org.opensearch.common.util.concurrent.ThreadContext;
import org.opensearch.threadpool.ThreadPool;
import org.opensearch.transport.TcpChannel;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashMap;
import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.Semaphore;
import java.util.concurrent.atomic.AtomicBoolean;
import java.util.concurrent.atomic.AtomicLong;
import java.util.stream.Collectors;
import java.util.stream.StreamSupport;
import static org.opensearch.common.unit.TimeValue.timeValueMillis;
import static org.opensearch.http.HttpTransportSettings.SETTING_HTTP_MAX_HEADER_SIZE;
/**
* Task Manager service for keeping track of currently running tasks on the nodes
*/
public class TaskManager implements ClusterStateApplier {
private static final Logger logger = LogManager.getLogger(TaskManager.class);
private static final TimeValue WAIT_FOR_COMPLETION_POLL = timeValueMillis(100);
/** Rest headers that are copied to the task */
private final List taskHeaders;
private final ThreadPool threadPool;
private final ConcurrentMapLong tasks = ConcurrentCollections.newConcurrentMapLongWithAggressiveConcurrency();
private final ConcurrentMapLong cancellableTasks = ConcurrentCollections
.newConcurrentMapLongWithAggressiveConcurrency();
private final AtomicLong taskIdGenerator = new AtomicLong();
private final Map banedParents = new ConcurrentHashMap<>();
private TaskResultsService taskResultsService;
private volatile DiscoveryNodes lastDiscoveryNodes = DiscoveryNodes.EMPTY_NODES;
private final ByteSizeValue maxHeaderSize;
private final Map channelPendingTaskTrackers = ConcurrentCollections.newConcurrentMap();
private final SetOnce cancellationService = new SetOnce<>();
public TaskManager(Settings settings, ThreadPool threadPool, Set taskHeaders) {
this.threadPool = threadPool;
this.taskHeaders = new ArrayList<>(taskHeaders);
this.maxHeaderSize = SETTING_HTTP_MAX_HEADER_SIZE.get(settings);
}
public void setTaskResultsService(TaskResultsService taskResultsService) {
assert this.taskResultsService == null;
this.taskResultsService = taskResultsService;
}
public void setTaskCancellationService(TaskCancellationService taskCancellationService) {
this.cancellationService.set(taskCancellationService);
}
/**
* Registers a task without parent task
*/
public Task register(String type, String action, TaskAwareRequest request) {
Map headers = new HashMap<>();
long headerSize = 0;
long maxSize = maxHeaderSize.getBytes();
ThreadContext threadContext = threadPool.getThreadContext();
for (String key : taskHeaders) {
String httpHeader = threadContext.getHeader(key);
if (httpHeader != null) {
headerSize += key.length() * 2 + httpHeader.length() * 2;
if (headerSize > maxSize) {
throw new IllegalArgumentException("Request exceeded the maximum size of task headers " + maxHeaderSize);
}
headers.put(key, httpHeader);
}
}
Task task = request.createTask(taskIdGenerator.incrementAndGet(), type, action, request.getParentTask(), headers);
Objects.requireNonNull(task);
assert task.getParentTaskId().equals(request.getParentTask()) : "Request [ " + request + "] didn't preserve it parentTaskId";
if (logger.isTraceEnabled()) {
logger.trace("register {} [{}] [{}] [{}]", task.getId(), type, action, task.getDescription());
}
if (task instanceof CancellableTask) {
registerCancellableTask(task);
} else {
Task previousTask = tasks.put(task.getId(), task);
assert previousTask == null;
}
return task;
}
private void registerCancellableTask(Task task) {
CancellableTask cancellableTask = (CancellableTask) task;
CancellableTaskHolder holder = new CancellableTaskHolder(cancellableTask);
CancellableTaskHolder oldHolder = cancellableTasks.put(task.getId(), holder);
assert oldHolder == null;
// Check if this task was banned before we start it. The empty check is used to avoid
// computing the hash code of the parent taskId as most of the time banedParents is empty.
if (task.getParentTaskId().isSet() && banedParents.isEmpty() == false) {
String reason = banedParents.get(task.getParentTaskId());
if (reason != null) {
try {
holder.cancel(reason);
throw new TaskCancelledException("Task cancelled before it started: " + reason);
} finally {
// let's clean up the registration
unregister(task);
}
}
}
}
/**
* Cancels a task
*
* After starting cancellation on the parent task, the task manager tries to cancel all children tasks
* of the current task. Once cancellation of the children tasks is done, the listener is triggered.
* If the task is completed or unregistered from TaskManager, then the listener is called immediately.
*/
public void cancel(CancellableTask task, String reason, Runnable listener) {
CancellableTaskHolder holder = cancellableTasks.get(task.getId());
if (holder != null) {
logger.trace("cancelling task with id {}", task.getId());
holder.cancel(reason, listener);
} else {
listener.run();
}
}
/**
* Unregister the task
*/
public Task unregister(Task task) {
logger.trace("unregister task for id: {}", task.getId());
if (task instanceof CancellableTask) {
CancellableTaskHolder holder = cancellableTasks.remove(task.getId());
if (holder != null) {
holder.finish();
return holder.getTask();
} else {
return null;
}
} else {
return tasks.remove(task.getId());
}
}
/**
* Register a node on which a child task will execute. The returned {@link Releasable} must be called
* to unregister the child node once the child task is completed or failed.
*/
public Releasable registerChildNode(long taskId, DiscoveryNode node) {
final CancellableTaskHolder holder = cancellableTasks.get(taskId);
if (holder != null) {
logger.trace("register child node [{}] task [{}]", node, taskId);
holder.registerChildNode(node);
return Releasables.releaseOnce(() -> {
logger.trace("unregister child node [{}] task [{}]", node, taskId);
holder.unregisterChildNode(node);
});
}
return () -> {};
}
public DiscoveryNode localNode() {
return lastDiscoveryNodes.getLocalNode();
}
/**
* Stores the task failure
*/
public void storeResult(Task task, Exception error, ActionListener listener) {
DiscoveryNode localNode = lastDiscoveryNodes.getLocalNode();
if (localNode == null) {
// too early to store anything, shouldn't really be here - just pass the error along
listener.onFailure(error);
return;
}
final TaskResult taskResult;
try {
taskResult = task.result(localNode, error);
} catch (IOException ex) {
logger.warn(() -> new ParameterizedMessage("couldn't store error {}", ExceptionsHelper.detailedMessage(error)), ex);
listener.onFailure(ex);
return;
}
taskResultsService.storeResult(taskResult, new ActionListener() {
@Override
public void onResponse(Void aVoid) {
listener.onFailure(error);
}
@Override
public void onFailure(Exception e) {
logger.warn(() -> new ParameterizedMessage("couldn't store error {}", ExceptionsHelper.detailedMessage(error)), e);
listener.onFailure(e);
}
});
}
/**
* Stores the task result
*/
public void storeResult(Task task, Response response, ActionListener listener) {
DiscoveryNode localNode = lastDiscoveryNodes.getLocalNode();
if (localNode == null) {
// too early to store anything, shouldn't really be here - just pass the response along
logger.warn("couldn't store response {}, the node didn't join the cluster yet", response);
listener.onResponse(response);
return;
}
final TaskResult taskResult;
try {
taskResult = task.result(localNode, response);
} catch (IOException ex) {
logger.warn(() -> new ParameterizedMessage("couldn't store response {}", response), ex);
listener.onFailure(ex);
return;
}
taskResultsService.storeResult(taskResult, new ActionListener() {
@Override
public void onResponse(Void aVoid) {
listener.onResponse(response);
}
@Override
public void onFailure(Exception e) {
logger.warn(() -> new ParameterizedMessage("couldn't store response {}", response), e);
listener.onFailure(e);
}
});
}
/**
* Returns the list of currently running tasks on the node
*/
public Map getTasks() {
HashMap taskHashMap = new HashMap<>(this.tasks);
for (CancellableTaskHolder holder : cancellableTasks.values()) {
taskHashMap.put(holder.getTask().getId(), holder.getTask());
}
return Collections.unmodifiableMap(taskHashMap);
}
/**
* Returns the list of currently running tasks on the node that can be cancelled
*/
public Map getCancellableTasks() {
HashMap taskHashMap = new HashMap<>();
for (CancellableTaskHolder holder : cancellableTasks.values()) {
taskHashMap.put(holder.getTask().getId(), holder.getTask());
}
return Collections.unmodifiableMap(taskHashMap);
}
/**
* Returns a task with given id, or null if the task is not found.
*/
public Task getTask(long id) {
Task task = tasks.get(id);
if (task != null) {
return task;
} else {
return getCancellableTask(id);
}
}
/**
* Returns a cancellable task with given id, or null if the task is not found.
*/
public CancellableTask getCancellableTask(long id) {
CancellableTaskHolder holder = cancellableTasks.get(id);
if (holder != null) {
return holder.getTask();
} else {
return null;
}
}
/**
* Returns the number of currently banned tasks.
*
* Will be used in task manager stats and for debugging.
*/
public int getBanCount() {
return banedParents.size();
}
/**
* Bans all tasks with the specified parent task from execution, cancels all tasks that are currently executing.
*
* This method is called when a parent task that has children is cancelled.
* @return a list of pending cancellable child tasks
*/
public List setBan(TaskId parentTaskId, String reason) {
logger.trace("setting ban for the parent task {} {}", parentTaskId, reason);
// Set the ban first, so the newly created tasks cannot be registered
synchronized (banedParents) {
if (lastDiscoveryNodes.nodeExists(parentTaskId.getNodeId())) {
// Only set the ban if the node is the part of the cluster
banedParents.put(parentTaskId, reason);
}
}
return cancellableTasks.values().stream().filter(t -> t.hasParent(parentTaskId)).map(t -> t.task).collect(Collectors.toList());
}
/**
* Removes the ban for the specified parent task.
*
* This method is called when a previously banned task finally cancelled
*/
public void removeBan(TaskId parentTaskId) {
logger.trace("removing ban for the parent task {}", parentTaskId);
banedParents.remove(parentTaskId);
}
// for testing
public Set getBannedTaskIds() {
return Collections.unmodifiableSet(banedParents.keySet());
}
/**
* Start rejecting new child requests as the parent task was cancelled.
*
* @param taskId the parent task id
* @param onChildTasksCompleted called when all child tasks are completed or failed
* @return the set of current nodes that have outstanding child tasks
*/
public Collection startBanOnChildrenNodes(long taskId, Runnable onChildTasksCompleted) {
final CancellableTaskHolder holder = cancellableTasks.get(taskId);
if (holder != null) {
return holder.startBan(onChildTasksCompleted);
} else {
onChildTasksCompleted.run();
return Collections.emptySet();
}
}
@Override
public void applyClusterState(ClusterChangedEvent event) {
lastDiscoveryNodes = event.state().getNodes();
if (event.nodesRemoved()) {
synchronized (banedParents) {
lastDiscoveryNodes = event.state().getNodes();
// Remove all bans that were registered by nodes that are no longer in the cluster state
Iterator banIterator = banedParents.keySet().iterator();
while (banIterator.hasNext()) {
TaskId taskId = banIterator.next();
if (lastDiscoveryNodes.nodeExists(taskId.getNodeId()) == false) {
logger.debug(
"Removing ban for the parent [{}] on the node [{}], reason: the parent node is gone",
taskId,
event.state().getNodes().getLocalNode()
);
banIterator.remove();
}
}
}
}
}
/**
* Blocks the calling thread, waiting for the task to vanish from the TaskManager.
*/
public void waitForTaskCompletion(Task task, long untilInNanos) {
while (System.nanoTime() - untilInNanos < 0) {
if (getTask(task.getId()) == null) {
return;
}
try {
Thread.sleep(WAIT_FOR_COMPLETION_POLL.millis());
} catch (InterruptedException e) {
throw new OpenSearchException("Interrupted waiting for completion of [{}]", e, task);
}
}
throw new OpenSearchTimeoutException("Timed out waiting for completion of [{}]", task);
}
private static class CancellableTaskHolder {
private final CancellableTask task;
private boolean finished = false;
private List cancellationListeners = null;
private ObjectIntMap childTasksPerNode = null;
private boolean banChildren = false;
private List childTaskCompletedListeners = null;
CancellableTaskHolder(CancellableTask task) {
this.task = task;
}
void cancel(String reason, Runnable listener) {
final Runnable toRun;
synchronized (this) {
if (finished) {
assert cancellationListeners == null;
toRun = listener;
} else {
toRun = () -> {};
if (listener != null) {
if (cancellationListeners == null) {
cancellationListeners = new ArrayList<>();
}
cancellationListeners.add(listener);
}
}
}
try {
task.cancel(reason);
} finally {
if (toRun != null) {
toRun.run();
}
}
}
void cancel(String reason) {
task.cancel(reason);
}
/**
* Marks task as finished.
*/
public void finish() {
final List listeners;
synchronized (this) {
this.finished = true;
if (cancellationListeners != null) {
listeners = cancellationListeners;
cancellationListeners = null;
} else {
listeners = Collections.emptyList();
}
}
// We need to call the listener outside of the synchronised section to avoid potential bottle necks
// in the listener synchronization
notifyListeners(listeners);
}
private void notifyListeners(List listeners) {
assert Thread.holdsLock(this) == false;
Exception rootException = null;
for (Runnable listener : listeners) {
try {
listener.run();
} catch (RuntimeException inner) {
rootException = ExceptionsHelper.useOrSuppress(rootException, inner);
}
}
ExceptionsHelper.reThrowIfNotNull(rootException);
}
public boolean hasParent(TaskId parentTaskId) {
return task.getParentTaskId().equals(parentTaskId);
}
public CancellableTask getTask() {
return task;
}
synchronized void registerChildNode(DiscoveryNode node) {
if (banChildren) {
throw new TaskCancelledException("The parent task was cancelled, shouldn't start any child tasks");
}
if (childTasksPerNode == null) {
childTasksPerNode = new ObjectIntHashMap<>();
}
childTasksPerNode.addTo(node, 1);
}
void unregisterChildNode(DiscoveryNode node) {
final List listeners;
synchronized (this) {
if (childTasksPerNode.addTo(node, -1) == 0) {
childTasksPerNode.remove(node);
}
if (childTasksPerNode.isEmpty() && this.childTaskCompletedListeners != null) {
listeners = childTaskCompletedListeners;
childTaskCompletedListeners = null;
} else {
listeners = Collections.emptyList();
}
}
notifyListeners(listeners);
}
Set startBan(Runnable onChildTasksCompleted) {
final Set pendingChildNodes;
final Runnable toRun;
synchronized (this) {
banChildren = true;
if (childTasksPerNode == null) {
pendingChildNodes = Collections.emptySet();
} else {
pendingChildNodes = StreamSupport.stream(childTasksPerNode.spliterator(), false)
.map(e -> e.key)
.collect(Collectors.toSet());
}
if (pendingChildNodes.isEmpty()) {
assert childTaskCompletedListeners == null;
toRun = onChildTasksCompleted;
} else {
toRun = () -> {};
if (childTaskCompletedListeners == null) {
childTaskCompletedListeners = new ArrayList<>();
}
childTaskCompletedListeners.add(onChildTasksCompleted);
}
}
toRun.run();
return pendingChildNodes;
}
}
/**
* Start tracking a cancellable task with its tcp channel, so if the channel gets closed we can get a set of
* pending tasks associated that channel and cancel them as these results won't be retrieved by the parent task.
*
* @return a releasable that should be called when this pending task is completed
*/
public Releasable startTrackingCancellableChannelTask(TcpChannel channel, CancellableTask task) {
assert cancellableTasks.containsKey(task.getId()) : "task [" + task.getId() + "] is not registered yet";
final ChannelPendingTaskTracker tracker = channelPendingTaskTrackers.compute(channel, (k, curr) -> {
if (curr == null) {
curr = new ChannelPendingTaskTracker();
}
curr.addTask(task);
return curr;
});
if (tracker.registered.compareAndSet(false, true)) {
channel.addCloseListener(ActionListener.wrap(r -> {
final ChannelPendingTaskTracker removedTracker = channelPendingTaskTrackers.remove(channel);
assert removedTracker == tracker;
cancelTasksOnChannelClosed(tracker.drainTasks());
}, e -> { assert false : new AssertionError("must not be here", e); }));
}
return () -> tracker.removeTask(task);
}
// for testing
final int numberOfChannelPendingTaskTrackers() {
return channelPendingTaskTrackers.size();
}
private static class ChannelPendingTaskTracker {
final AtomicBoolean registered = new AtomicBoolean();
final Semaphore permits = Assertions.ENABLED ? new Semaphore(Integer.MAX_VALUE) : null;
final Set pendingTasks = ConcurrentCollections.newConcurrentSet();
void addTask(CancellableTask task) {
assert permits.tryAcquire() : "tracker was drained";
final boolean added = pendingTasks.add(task);
assert added : "task " + task.getId() + " is in the pending list already";
assert releasePermit();
}
boolean acquireAllPermits() {
permits.acquireUninterruptibly(Integer.MAX_VALUE);
return true;
}
boolean releasePermit() {
permits.release();
return true;
}
Set drainTasks() {
assert acquireAllPermits(); // do not release permits so we can't add tasks to this tracker after draining
return Collections.unmodifiableSet(pendingTasks);
}
void removeTask(CancellableTask task) {
final boolean removed = pendingTasks.remove(task);
assert removed : "task " + task.getId() + " is not in the pending list";
}
}
private void cancelTasksOnChannelClosed(Set tasks) {
if (tasks.isEmpty() == false) {
threadPool.generic().execute(new AbstractRunnable() {
@Override
public void onFailure(Exception e) {
logger.warn("failed to cancel tasks on channel closed", e);
}
@Override
protected void doRun() {
for (CancellableTask task : tasks) {
cancelTaskAndDescendants(task, "channel was closed", false, ActionListener.wrap(() -> {}));
}
}
});
}
}
public void cancelTaskAndDescendants(CancellableTask task, String reason, boolean waitForCompletion, ActionListener listener) {
final TaskCancellationService service = cancellationService.get();
if (service != null) {
service.cancelTaskAndDescendants(task, reason, waitForCompletion, listener);
} else {
assert false : "TaskCancellationService is not initialized";
throw new IllegalStateException("TaskCancellationService is not initialized");
}
}
}