| // Copyright 2016 Twitter. All rights reserved. |
| // |
| // Licensed 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 com.twitter.heron.api.topology; |
| |
| import com.twitter.heron.classification.InterfaceAudience; |
| import com.twitter.heron.classification.InterfaceStability; |
| |
| /** |
| * Bolt or spout instances should implement this method if they wish to be informed of changed to |
| * the topology context during the lifecycle of the instance. The TopologyContext is backed by |
| * elements of the physical plan, which can change during a scaling event. Instances that need to |
| * adapt to such changes should implement this interface to receive a callback when a change occurs. |
| */ |
| @InterfaceAudience.Public |
| @InterfaceStability.Evolving |
| public interface IUpdatable { |
| void update(TopologyContext topologyContext); |
| } |