Repository: apache/flink
File: flink-runtime/src/main/java/org/apache/flink/runtime/resourcemanager/slotmanager/ClusterResourceStatisticsProvider.java (Java)

Code before:
 * 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.resourcemanager.slotmanager;

import org.apache.flink.runtime.clusterframework.types.ResourceProfile;
import org.apache.flink.runtime.instance.InstanceID;

import javax.annotation.Nullable;

/** Provides statistics of cluster resources. */
public interface ClusterResourceStatisticsProvider {

    /** Get total number of tasks assigned to the current instance. slots. */
    @Nullable
    Integer getAssignedTasks(InstanceID instanceId);

    /** Get total number of registered slots. */
    int getNumberRegisteredSlots();

    /** Get number of registered slots from the TaskManager with the given instance id. */
    int getNumberRegisteredSlotsOf(InstanceID instanceId);

    /** Get total number of free slots. */
    int getNumberFreeSlots();

    /** Get number of free slots from the TaskManager with the given instance id. */
    int getNumberFreeSlotsOf(InstanceID instanceId);

    /** Get profile of total registered resources. */
    ResourceProfile getRegisteredResource();

    /** Get profile of registered resources from the TaskManager with the given instance id. */
    ResourceProfile getRegisteredResourceOf(InstanceID instanceId);

    /** Get profile of total free resources. */
    ResourceProfile getFreeResource();

    /** Get profile of free resources from the TaskManager with the given instance id. */
    ResourceProfile getFreeResourceOf(InstanceID instanceId);


Review comment (suggestion):
Any specific reason to make this a nullable object instead of a primitive `int`, just like the other numeric statistics we already have? And I mean it for any interface/class we added this, so `SlotManager` and `TaskManagerSlotInformation` as well.

`getNumberRegisteredSlotsOf(InstanceID instanceId)` is also optional, and we just return `0` in that case. That's simpler code wise and in this context `null` means `0`, so it seems to be fine, hence I'm not sure why we handle this differently.


Code after:
 * 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.resourcemanager.slotmanager;

import org.apache.flink.runtime.clusterframework.types.ResourceProfile;
import org.apache.flink.runtime.instance.InstanceID;

/** Provides statistics of cluster resources. */
public interface ClusterResourceStatisticsProvider {

    /** Get total number of tasks assigned to the current instance. slots. */
    int getAssignedTasks(InstanceID instanceId);

    /** Get total number of registered slots. */
    int getNumberRegisteredSlots();

    /** Get number of registered slots from the TaskManager with the given instance id. */
    int getNumberRegisteredSlotsOf(InstanceID instanceId);

    /** Get total number of free slots. */
    int getNumberFreeSlots();

    /** Get number of free slots from the TaskManager with the given instance id. */
    int getNumberFreeSlotsOf(InstanceID instanceId);

    /** Get profile of total registered resources. */
    ResourceProfile getRegisteredResource();

    /** Get profile of registered resources from the TaskManager with the given instance id. */
    ResourceProfile getRegisteredResourceOf(InstanceID instanceId);

    /** Get profile of total free resources. */
    ResourceProfile getFreeResource();

    /** Get profile of free resources from the TaskManager with the given instance id. */
    ResourceProfile getFreeResourceOf(InstanceID instanceId);

    /** Get profile of total pending resources. */
    ResourceProfile getPendingResource();
}