/** * 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.classification.InterfaceStability; /** * This is the JMX management interface for NameNode status information */ @InterfaceAudience.Public @InterfaceStability.Evolving public interface NameNodeStatusMXBean { /** * Gets the NameNode role. * * @return the NameNode role. */ public String getNNRole(); /** * Gets the NameNode state. * * @return the NameNode state. */ public String getState(); /** * Gets the host and port colon separated. * * @return host and port colon separated. */ public String getHostAndPort(); /** * Gets if security is enabled. * * @return true, if security is enabled. */ public boolean isSecurityEnabled(); /** * Gets the most recent HA transition time in milliseconds from the epoch. * * @return the most recent HA transition time in milliseconds from the epoch. */ public long getLastHATransitionTime(); /** * Gets number of bytes in blocks with future generation stamps. * @return number of bytes that can be deleted if exited from safe mode. */ long getBytesWithFutureGenerationStamps(); /** * Retrieves information about slow DataNodes, if the feature is * enabled. The report is in a JSON format. */ String getSlowPeersReport(); }