| /* |
| * 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.hbase.util; |
| |
| import edu.umd.cs.findbugs.annotations.NonNull; |
| import java.lang.reflect.Method; |
| import java.net.UnknownHostException; |
| |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.hbase.HBaseInterfaceAudience; |
| import org.apache.yetus.audience.InterfaceAudience; |
| |
| /** |
| * Wrapper around Hadoop's DNS class to hide reflection. |
| */ |
| @InterfaceAudience.Private |
| @edu.umd.cs.findbugs.annotations.SuppressWarnings(value="REC_CATCH_EXCEPTION", |
| justification="If exception, presume HAS_NEW_DNS_GET_DEFAULT_HOST_API false") |
| public final class DNS { |
| // key to the config parameter of server hostname |
| // the specification of server hostname is optional. The hostname should be resolvable from |
| // both master and region server |
| @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG) |
| public static final String UNSAFE_RS_HOSTNAME_KEY = "hbase.unsafe.regionserver.hostname"; |
| @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG) |
| public static final String MASTER_HOSTNAME_KEY = "hbase.master.hostname"; |
| |
| private static boolean HAS_NEW_DNS_GET_DEFAULT_HOST_API; |
| private static Method GET_DEFAULT_HOST_METHOD; |
| |
| /** |
| * @deprecated since 2.4.0 and will be removed in 4.0.0. |
| * Use {@link DNS#UNSAFE_RS_HOSTNAME_KEY} instead. |
| * @see <a href="https://issues.apache.org/jira/browse/HBASE-24667">HBASE-24667</a> |
| */ |
| @Deprecated |
| @InterfaceAudience.LimitedPrivate(HBaseInterfaceAudience.CONFIG) |
| public static final String RS_HOSTNAME_KEY = "hbase.regionserver.hostname"; |
| |
| static { |
| try { |
| GET_DEFAULT_HOST_METHOD = org.apache.hadoop.net.DNS.class |
| .getMethod("getDefaultHost", String.class, String.class, boolean.class); |
| HAS_NEW_DNS_GET_DEFAULT_HOST_API = true; |
| } catch (Exception e) { |
| HAS_NEW_DNS_GET_DEFAULT_HOST_API = false; // FindBugs: Causes REC_CATCH_EXCEPTION. Suppressed |
| } |
| Configuration.addDeprecation(RS_HOSTNAME_KEY, UNSAFE_RS_HOSTNAME_KEY); |
| } |
| |
| public enum ServerType { |
| MASTER("master"), |
| REGIONSERVER("regionserver"); |
| |
| private String name; |
| ServerType(String name) { |
| this.name = name; |
| } |
| |
| public String getName() { |
| return name; |
| } |
| } |
| |
| private DNS() {} |
| |
| /** |
| * Wrapper around DNS.getDefaultHost(String, String), calling |
| * DNS.getDefaultHost(String, String, boolean) when available. |
| * |
| * @param strInterface The network interface to query. |
| * @param nameserver The DNS host name. |
| * @return The default host names associated with IPs bound to the network interface. |
| */ |
| public static String getDefaultHost(String strInterface, String nameserver) |
| throws UnknownHostException { |
| if (HAS_NEW_DNS_GET_DEFAULT_HOST_API) { |
| try { |
| // Hadoop-2.8 includes a String, String, boolean variant of getDefaultHost |
| // which properly handles multi-homed systems with Kerberos. |
| return (String) GET_DEFAULT_HOST_METHOD.invoke(null, strInterface, nameserver, true); |
| } catch (Exception e) { |
| // If we can't invoke the method as it should exist, throw an exception |
| throw new RuntimeException("Failed to invoke DNS.getDefaultHost via reflection", e); |
| } |
| } else { |
| return org.apache.hadoop.net.DNS.getDefaultHost(strInterface, nameserver); |
| } |
| } |
| |
| /** |
| * Get the configured hostname for a given ServerType. Gets the default hostname if not specified |
| * in the configuration. |
| * @param conf Configuration to look up. |
| * @param serverType ServerType to look up in the configuration for overrides. |
| */ |
| public static String getHostname(@NonNull Configuration conf, @NonNull ServerType serverType) |
| throws UnknownHostException { |
| String hostname; |
| switch (serverType) { |
| case MASTER: |
| hostname = conf.get(MASTER_HOSTNAME_KEY); |
| break; |
| case REGIONSERVER: |
| hostname = conf.get(UNSAFE_RS_HOSTNAME_KEY); |
| break; |
| default: |
| hostname = null; |
| } |
| if (hostname == null || hostname.isEmpty()) { |
| return Strings.domainNamePointerToHostName(getDefaultHost( |
| conf.get("hbase." + serverType.getName() + ".dns.interface", "default"), |
| conf.get("hbase." + serverType.getName() + ".dns.nameserver", "default"))); |
| } else { |
| return hostname; |
| } |
| } |
| } |