/**
* 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.hdfs.server.namenode;
/**
* A pluggabe safe mode interface.
*/
public interface SafeModeInfo {
/**
* A tip on how safe mode is to be turned off: manually or automatically.
*/
public String getTurnOffTip();
/**
* Check if safe mode was entered manually or at startup.
*/
public boolean isManual();
/**
* Check if safe mode is on.
*
* @return true if in safe mode
*/
public boolean isOn();
/**
* Leave safe mode.
* <p/>
* Switch to manual safe mode if distributed upgrade is required.<br>
* Check for invalid, under- & over-replicated blocks in the end of startup.
*
* @param checkForUpgrades
* whether or not we need to check for upgrades
*/
public void leave(boolean checkForUpgrades);
/**
* Enter safemode manually.
*/
public void setManual();
/**
* Shutdown the safe mode.
*/
public void shutdown();
/**
* Whether or not we can leave safe mode.
* @return true if can leave or false otherwise.
*/
public boolean canLeave();
/**
* Check and trigger safe mode if needed.
*/
public void checkMode();
}