/**
* 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 org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hdfs.protocol.Block;
/** 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();
/** Is the system in safe mode? */
public boolean isInSafeMode();
/**
* Is the system in startup safe mode, i.e. the system is starting up with
* safe mode turned on automatically?
*/
public boolean isInStartupSafeMode();
/** Check whether replication queues are being populated. */
public boolean isPopulatingReplQueues();
/**
* Increment number of blocks that reached minimal replication.
* @param replication current replication
*/
public void incrementSafeBlockCount(int replication);
/** Decrement number of blocks that reached minimal replication. */
public void decrementSafeBlockCount(Block b);
}