| /* |
| * 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.brooklyn.core.entity.trait; |
| |
| |
| import org.apache.brooklyn.core.annotation.Effector; |
| import org.apache.brooklyn.core.annotation.EffectorParam; |
| import org.apache.brooklyn.core.effector.MethodEffector; |
| |
| /** |
| * Defines an entity group that can be re-sized dynamically. |
| * <p/> |
| * By invoking the {@link #resize(Integer)} effector, the number of child nodes |
| * can be reduced (by shutting down some of them) or increased (by provisioning new entities.) |
| */ |
| public interface Resizable { |
| |
| /** |
| * Indicates that resizing up to the desired size is not possible - only resized to the |
| * {@link Resizable#getCurrentSize()}, because there is insufficient capacity. |
| */ |
| public static class InsufficientCapacityException extends RuntimeException { |
| private static final long serialVersionUID = 953230498564942446L; |
| |
| public InsufficientCapacityException(String msg) { |
| super(msg); |
| } |
| public InsufficientCapacityException(String msg, Throwable cause) { |
| super(msg, cause); |
| } |
| } |
| |
| MethodEffector<Integer> RESIZE = new MethodEffector<Integer>(Resizable.class, "resize"); |
| |
| /** |
| * Grow or shrink this entity to the desired size. |
| * |
| * @param desiredSize the new size of the entity group. |
| * @return the new size of the group. |
| * |
| * @throws InsufficientCapacityException If the request was to grow, but there is no capacity to grow to |
| * the desired size. |
| */ |
| @Effector(description="Changes the size of the entity (e.g. the number of nodes in a cluster)") |
| Integer resize(@EffectorParam(name="desiredSize", description="The new size of the cluster") Integer desiredSize); |
| |
| /** |
| * @return the current size of the group. |
| */ |
| Integer getCurrentSize(); |
| } |
| |