/** * 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.hadoop.yarn.server.resourcemanager.reservation; import org.apache.hadoop.yarn.api.records.ReservationDefinition; /** * A Plan represents the central data structure of a reservation system that * maintains the "agenda" for the cluster. In particular, it maintains * information on how a set of {@link ReservationDefinition} that have been * previously accepted will be honored. * * {@link ReservationDefinition} submitted by the users through the RM public * APIs are passed to appropriate {@link ReservationAgent}s, which in turn will * consult the Plan (via the {@link PlanView} interface) and try to determine * whether there are sufficient resources available in this Plan to satisfy the * temporal and resource constraints of a {@link ReservationDefinition}. If a * valid allocation is found the agent will try to store it in the plan (via the * {@link PlanEdit} interface). Upon success the system return to the user a * positive acknowledgment, and a reservation identifier to be later used to * access the reserved resources. * * A {@link PlanFollower} will continuously read from the Plan and will * affect the instantaneous allocation of resources among jobs running by * publishing the "current" slice of the Plan to the underlying scheduler. I.e., * the configuration of queues/weights of the scheduler are modified to reflect * the allocations in the Plan. * * As this interface have several methods we decompose them into three groups: * {@link PlanContext}: containing configuration type information, * {@link PlanView} read-only access to the plan state, and {@link PlanEdit} * write access to the plan state. */ public interface Plan extends PlanContext, PlanView, PlanEdit { }