org.apache.flink.runtime.instance.SimpleSlot Maven / Gradle / Ivy
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* 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.flink.runtime.instance;
import org.apache.flink.runtime.clusterframework.types.AllocationID;
import org.apache.flink.runtime.jobmanager.scheduler.Locality;
import org.apache.flink.runtime.jobmanager.slots.TaskManagerGateway;
import org.apache.flink.runtime.jobmaster.LogicalSlot;
import org.apache.flink.runtime.jobmaster.SlotContext;
import org.apache.flink.runtime.jobmaster.SlotOwner;
import org.apache.flink.runtime.jobmaster.SlotRequestId;
import org.apache.flink.runtime.taskmanager.TaskManagerLocation;
import org.apache.flink.util.AbstractID;
import org.apache.flink.util.FlinkException;
import org.apache.flink.util.Preconditions;
import javax.annotation.Nullable;
import java.util.concurrent.CompletableFuture;
import java.util.concurrent.atomic.AtomicReferenceFieldUpdater;
/**
* A SimpleSlot represents a single slot on a TaskManager instance, or a slot within a shared slot.
*
* If this slot is part of a {@link SharedSlot}, then the parent attribute will point to that shared slot.
* If not, then the parent attribute is null.
*/
public class SimpleSlot extends Slot implements LogicalSlot {
/** The updater used to atomically swap in the payload */
private static final AtomicReferenceFieldUpdater PAYLOAD_UPDATER =
AtomicReferenceFieldUpdater.newUpdater(SimpleSlot.class, Payload.class, "payload");
// ------------------------------------------------------------------------
private final CompletableFuture releaseFuture = new CompletableFuture<>();
/** Id of the task being executed in the slot. Volatile to force a memory barrier and allow for correct double-checking */
private volatile Payload payload;
/** The locality attached to the slot, defining whether the slot was allocated at the desired location. */
private volatile Locality locality = Locality.UNCONSTRAINED;
// ------------------------------------------------------------------------
// Old Constructors (legacy mode)
// ------------------------------------------------------------------------
/**
* Creates a new simple slot that stands alone and does not belong to shared slot.
*
* @param owner The component from which this slot is allocated.
* @param location The location info of the TaskManager where the slot was allocated from
* @param slotNumber The number of the task slot on the instance.
* @param taskManagerGateway The gateway to communicate with the TaskManager of this slot
*/
public SimpleSlot(
SlotOwner owner, TaskManagerLocation location, int slotNumber,
TaskManagerGateway taskManagerGateway) {
this(owner, location, slotNumber, taskManagerGateway, null, null);
}
/**
* Creates a new simple slot that belongs to the given shared slot and
* is identified by the given ID.
*
* @param owner The component from which this slot is allocated.
* @param location The location info of the TaskManager where the slot was allocated from
* @param slotNumber The number of the simple slot in its parent shared slot.
* @param taskManagerGateway to communicate with the associated task manager.
* @param parent The parent shared slot.
* @param groupID The ID that identifies the group that the slot belongs to.
*/
public SimpleSlot(
SlotOwner owner,
TaskManagerLocation location,
int slotNumber,
TaskManagerGateway taskManagerGateway,
@Nullable SharedSlot parent,
@Nullable AbstractID groupID) {
super(
parent != null ?
parent.getSlotContext() :
new SimpleSlotContext(
NO_ALLOCATION_ID,
location,
slotNumber,
taskManagerGateway),
owner,
slotNumber,
parent,
groupID);
}
// ------------------------------------------------------------------------
// Constructors
// ------------------------------------------------------------------------
/**
* Creates a new simple slot that stands alone and does not belong to shared slot.
*
* @param slotContext The slot context of this simple slot
* @param owner The component from which this slot is allocated.
*/
public SimpleSlot(SlotContext slotContext, SlotOwner owner, int slotNumber) {
this(slotContext, owner, slotNumber, null, null);
}
/**
* Creates a new simple slot that belongs to the given shared slot and
* is identified by the given ID..
*
* @param parent The parent shared slot.
* @param owner The component from which this slot is allocated.
* @param groupID The ID that identifies the group that the slot belongs to.
*/
public SimpleSlot(SharedSlot parent, SlotOwner owner, int slotNumber, AbstractID groupID) {
this(parent.getSlotContext(), owner, slotNumber, parent, groupID);
}
/**
* Creates a new simple slot that belongs to the given shared slot and
* is identified by the given ID..
*
* @param slotContext The slot context of this simple slot
* @param owner The component from which this slot is allocated.
* @param slotNumber The number of the simple slot in its parent shared slot.
* @param parent The parent shared slot.
* @param groupID The ID that identifies the group that the slot belongs to.
*/
private SimpleSlot(
SlotContext slotContext,
SlotOwner owner,
int slotNumber,
@Nullable SharedSlot parent,
@Nullable AbstractID groupID) {
super(slotContext, owner, slotNumber, parent, groupID);
}
// ------------------------------------------------------------------------
// Properties
// ------------------------------------------------------------------------
@Override
public int getNumberLeaves() {
return 1;
}
/**
* Atomically sets the executed vertex, if no vertex has been assigned to this slot so far.
*
* @param payload The vertex to assign to this slot.
* @return True, if the vertex was assigned, false, otherwise.
*/
@Override
public boolean tryAssignPayload(Payload payload) {
Preconditions.checkNotNull(payload);
// check that we can actually run in this slot
if (isCanceled()) {
return false;
}
// atomically assign the vertex
if (!PAYLOAD_UPDATER.compareAndSet(this, null, payload)) {
return false;
}
// we need to do a double check that we were not cancelled in the meantime
if (isCanceled()) {
this.payload = null;
return false;
}
return true;
}
@Nullable
@Override
public Payload getPayload() {
return payload;
}
/**
* Gets the locality information attached to this slot.
* @return The locality attached to the slot.
*/
public Locality getLocality() {
return locality;
}
/**
* Attached locality information to this slot.
* @param locality The locality attached to the slot.
*/
public void setLocality(Locality locality) {
this.locality = locality;
}
// ------------------------------------------------------------------------
// Cancelling & Releasing
// ------------------------------------------------------------------------
@Override
public CompletableFuture releaseSlot(@Nullable Throwable cause) {
if (!isCanceled()) {
final CompletableFuture terminationFuture;
if (payload != null) {
// trigger the failure of the slot payload
payload.fail(cause != null ? cause : new FlinkException("TaskManager was lost/killed: " + getTaskManagerLocation()));
// wait for the termination of the payload before releasing the slot
terminationFuture = payload.getTerminalStateFuture();
} else {
terminationFuture = CompletableFuture.completedFuture(null);
}
terminationFuture.whenComplete(
(Object ignored, Throwable throwable) -> {
// release directly (if we are directly allocated),
// otherwise release through the parent shared slot
if (getParent() == null) {
// we have to give back the slot to the owning instance
if (markCancelled()) {
getOwner().returnAllocatedSlot(this).whenComplete(
(value, t) -> {
if (t != null) {
releaseFuture.completeExceptionally(t);
} else {
releaseFuture.complete(null);
}
});
}
} else {
// we have to ask our parent to dispose us
getParent().releaseChild(this);
releaseFuture.complete(null);
}
});
}
return releaseFuture;
}
@Override
public int getPhysicalSlotNumber() {
return getRootSlotNumber();
}
@Override
public AllocationID getAllocationId() {
return getSlotContext().getAllocationId();
}
@Override
public SlotRequestId getSlotRequestId() {
return NO_SLOT_REQUEST_ID;
}
@Nullable
@Override
public SlotSharingGroupId getSlotSharingGroupId() {
return NO_SLOT_SHARING_GROUP_ID;
}
// ------------------------------------------------------------------------
// Utilities
// ------------------------------------------------------------------------
@Override
public String toString() {
return "SimpleSlot " + super.toString();
}
}