/*
* 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();
}