org.apache.flink.runtime.jobmaster.slotpool.AllocatedSlot 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.jobmaster.slotpool;
import org.apache.flink.runtime.clusterframework.types.AllocationID;
import org.apache.flink.runtime.clusterframework.types.ResourceID;
import org.apache.flink.runtime.clusterframework.types.ResourceProfile;
import org.apache.flink.runtime.clusterframework.types.SlotID;
import org.apache.flink.runtime.jobmanager.slots.TaskManagerGateway;
import org.apache.flink.runtime.jobmaster.SlotContext;
import org.apache.flink.runtime.taskmanager.TaskManagerLocation;
import java.util.concurrent.atomic.AtomicReference;
import static org.apache.flink.util.Preconditions.checkNotNull;
/**
* The {@code AllocatedSlot} represents a slot that the JobMaster allocated from a TaskExecutor.
* It represents a slice of allocated resources from the TaskExecutor.
*
* To allocate an {@code AllocatedSlot}, the requests a slot from the ResourceManager. The
* ResourceManager picks (or starts) a TaskExecutor that will then allocate the slot to the
* JobMaster and notify the JobMaster.
*
*
Note: Prior to the resource management changes introduced in (Flink Improvement Proposal 6),
* an AllocatedSlot was allocated to the JobManager as soon as the TaskManager registered at the
* JobManager. All slots had a default unknown resource profile.
*/
public class AllocatedSlot implements SlotContext {
/** The ID under which the slot is allocated. Uniquely identifies the slot. */
private final AllocationID allocationId;
/** The location information of the TaskManager to which this slot belongs */
private final TaskManagerLocation taskManagerLocation;
/** The resource profile of the slot provides */
private final ResourceProfile resourceProfile;
/** RPC gateway to call the TaskManager that holds this slot */
private final TaskManagerGateway taskManagerGateway;
/** The number of the slot on the TaskManager to which slot belongs. Purely informational. */
private final int physicalSlotNumber;
private final AtomicReference payloadReference;
// ------------------------------------------------------------------------
public AllocatedSlot(
AllocationID allocationId,
TaskManagerLocation location,
int physicalSlotNumber,
ResourceProfile resourceProfile,
TaskManagerGateway taskManagerGateway) {
this.allocationId = checkNotNull(allocationId);
this.taskManagerLocation = checkNotNull(location);
this.physicalSlotNumber = physicalSlotNumber;
this.resourceProfile = checkNotNull(resourceProfile);
this.taskManagerGateway = checkNotNull(taskManagerGateway);
payloadReference = new AtomicReference<>(null);
}
// ------------------------------------------------------------------------
/**
* Gets the Slot's unique ID defined by its TaskManager.
*/
public SlotID getSlotId() {
return new SlotID(getTaskManagerId(), physicalSlotNumber);
}
/**
* Gets the ID under which the slot is allocated, which uniquely identifies the slot.
*
* @return The ID under which the slot is allocated
*/
public AllocationID getAllocationId() {
return allocationId;
}
/**
* Gets the ID of the TaskManager on which this slot was allocated.
*
* This is equivalent to {@link #getTaskManagerLocation()#getTaskManagerId()}.
*
* @return This slot's TaskManager's ID.
*/
public ResourceID getTaskManagerId() {
return getTaskManagerLocation().getResourceID();
}
/**
* Gets the resource profile of the slot.
*
* @return The resource profile of the slot.
*/
public ResourceProfile getResourceProfile() {
return resourceProfile;
}
/**
* Gets the location info of the TaskManager that offers this slot.
*
* @return The location info of the TaskManager that offers this slot
*/
public TaskManagerLocation getTaskManagerLocation() {
return taskManagerLocation;
}
/**
* Gets the actor gateway that can be used to send messages to the TaskManager.
*
* This method should be removed once the new interface-based RPC abstraction is in place
*
* @return The actor gateway that can be used to send messages to the TaskManager.
*/
public TaskManagerGateway getTaskManagerGateway() {
return taskManagerGateway;
}
/**
* Returns the physical slot number of the allocated slot. The physical slot number corresponds
* to the slot index on the TaskExecutor.
*
* @return Physical slot number of the allocated slot
*/
public int getPhysicalSlotNumber() {
return physicalSlotNumber;
}
/**
* Returns true if this slot is not being used (e.g. a logical slot is allocated from this slot).
*
* @return true if a logical slot is allocated from this slot, otherwise false
*/
public boolean isUsed() {
return payloadReference.get() != null;
}
/**
* Tries to assign the given payload to this allocated slot. This only works if there has not
* been another payload assigned to this slot.
*
* @param payload to assign to this slot
* @return true if the payload could be assigned, otherwise false
*/
public boolean tryAssignPayload(Payload payload) {
return payloadReference.compareAndSet(null, payload);
}
/**
* Triggers the release of the assigned payload. If the payload could be released,
* then it is removed from the slot.
*
* @param cause of the release operation
*/
public void releasePayload(Throwable cause) {
final Payload payload = payloadReference.get();
if (payload != null) {
payload.release(cause);
payloadReference.set(null);
}
}
// ------------------------------------------------------------------------
/**
* This always returns a reference hash code.
*/
@Override
public final int hashCode() {
return super.hashCode();
}
/**
* This always checks based on reference equality.
*/
@Override
public final boolean equals(Object obj) {
return this == obj;
}
@Override
public String toString() {
return "AllocatedSlot " + allocationId + " @ " + taskManagerLocation + " - " + physicalSlotNumber;
}
// -----------------------------------------------------------------------
// Interfaces
// -----------------------------------------------------------------------
/**
* Payload which can be assigned to an {@link AllocatedSlot}.
*/
interface Payload {
/**
* Releases the payload
*
* @param cause of the payload release
*/
void release(Throwable cause);
}
}