/**
* 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;
import io.hops.exception.StorageException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
import java.io.IOException;
/**
* SafeMode related operations.
*/
@InterfaceAudience.Private
public interface SafeMode {
/**
* Check safe mode conditions.
* If the corresponding conditions are satisfied,
* trigger the system to enter/leave safe mode.
*/
public void checkSafeMode() throws IOException;
/**
* Is the system in safe mode?
*/
public boolean isInSafeMode() throws IOException;
/**
* Is the system in startup safe mode, i.e. the system is starting up with
* safe mode turned on automatically?
*/
public boolean isInStartupSafeMode() throws IOException;
/**
* Check whether replication queues are being populated.
*/
public boolean isPopulatingReplQueues();
/**
* Increment number of blocks that reached minimal replication.
*
* @param blk
* current block
*/
public void incrementSafeBlockCount(BlockInfo blk) throws IOException;
/**
* Decrement number of blocks that reached minimal replication.
* @param blk
* current block
*/
public void decrementSafeBlockCount(BlockInfo blk)
throws StorageException, IOException;
}