| /** |
| * 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.datanode.metrics; |
| |
| import java.io.IOException; |
| |
| /** |
| * |
| * This Interface defines the methods to get the status of a the FSDataset of |
| * a data 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 FSDatasetMBean is stable and should |
| * be published as an interface. |
| * |
| * <p> |
| * Data Node runtime statistic info is report in another MBean |
| * @see org.apache.hadoop.hdfs.server.datanode.metrics.DataNodeStatisticsMBean |
| * |
| */ |
| public interface FSDatasetMBean { |
| |
| /** |
| * Returns the total space (in bytes) used by dfs datanode |
| * @return the total space used by dfs datanode |
| * @throws IOException |
| */ |
| public long getDfsUsed() throws IOException; |
| |
| /** |
| * Returns total capacity (in bytes) of storage (used and unused) |
| * @return total capacity of storage (used and unused) |
| * @throws IOException |
| */ |
| public long getCapacity() throws IOException; |
| |
| /** |
| * Returns the amount of free storage space (in bytes) |
| * @return The amount of free storage space |
| * @throws IOException |
| */ |
| public long getRemaining() throws IOException; |
| |
| /** |
| * Returns the storage id of the underlying storage |
| */ |
| public String getStorageInfo(); |
| |
| } |