/**
* 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.metrics;
import org.apache.hadoop.classification.InterfaceAudience;
/**
*
* This Interface defines the methods to get the status of a the FSNamesystem of
* a name node.
* It is also used for publishing via JMX (hence we follow the JMX naming
* convention.)
*
* Note we have not used the MetricsDynamicMBeanBase to implement this
* because the interface for the NameNodeStateMBean is stable and should
* be published as an interface.
*
* <p>
* Name Node runtime activity statistic info is reported in
* @see org.apache.hadoop.hdfs.server.namenode.metrics.NameNodeMetrics
*
*/
@InterfaceAudience.Private
public interface FSNamesystemMBean {
/**
* The state of the file system: Safemode or Operational
* @return the state
*/
public String getFSState();
/**
* Number of allocated blocks in the system
* @return - number of allocated blocks
*/
public long getBlocksTotal();
/**
* Total storage capacity
* @return - total capacity in bytes
*/
public long getCapacityTotal();
/**
* Free (unused) storage capacity
* @return - free capacity in bytes
*/
public long getCapacityRemaining();
/**
* Used storage capacity
* @return - used capacity in bytes
*/
public long getCapacityUsed();
/**
* Total number of files and directories
* @return - num of files and directories
*/
public long getFilesTotal();
/**
* Blocks pending to be replicated
* @return - num of blocks to be replicated
*/
public long getPendingReplicationBlocks();
/**
* Blocks under replicated
* @return - num of blocks under replicated
*/
public long getUnderReplicatedBlocks();
/**
* Blocks scheduled for replication
* @return - num of blocks scheduled for replication
*/
public long getScheduledReplicationBlocks();
/**
* Total Load on the FSNamesystem
* @return - total load of FSNamesystem
*/
public int getTotalLoad();
/**
* Number of Live data nodes
* @return number of live data nodes
*/
public int getNumLiveDataNodes();
/**
* Number of dead data nodes
* @return number of dead data nodes
*/
public int getNumDeadDataNodes();
}