| /** |
| * 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 |
| * <p> |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * <p> |
| * 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.hdds.scm.ha; |
| |
| /** |
| * Interface for background services in SCM, including ReplicationManager, |
| * SCMBlockDeletingService and BackgroundPipelineCreator. |
| * |
| * Provide a fine-grained method to manipulate the status of these background |
| * services. |
| */ |
| public interface SCMService { |
| /** |
| * Notify raft or safe mode related status changed. |
| */ |
| void notifyStatusChanged(); |
| |
| /** |
| * @param event latest triggered event. |
| */ |
| default void notifyEventTriggered(Event event) { |
| } |
| |
| /** |
| * @return true, if next iteration of Service should take effect, |
| * false, if next iteration of Service should be skipped. |
| */ |
| boolean shouldRun(); |
| |
| /** |
| * @return name of the Service. |
| */ |
| String getServiceName(); |
| |
| /** |
| * Status of Service. |
| */ |
| enum ServiceStatus { |
| RUNNING, |
| PAUSING |
| } |
| |
| /** |
| * One time event. |
| */ |
| enum Event { |
| PRE_CHECK_COMPLETED, |
| NEW_NODE_HANDLER_TRIGGERED, |
| UNHEALTHY_TO_HEALTHY_NODE_HANDLER_TRIGGERED |
| } |
| |
| /** |
| * starts the SCM service. |
| */ |
| void start(); |
| |
| /** |
| * stops the SCM service. |
| */ |
| void stop(); |
| } |