| /** |
| * 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 |
| * <p> |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * <p> |
| * 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.ha; |
| |
| import java.net.InetSocketAddress; |
| import java.net.URI; |
| |
| import java.util.Collections; |
| |
| import org.apache.hadoop.classification.InterfaceAudience; |
| import org.apache.hadoop.classification.InterfaceStability; |
| import org.apache.hadoop.conf.Configuration; |
| import org.apache.hadoop.hdfs.client.HdfsClientConfigKeys; |
| import org.apache.hadoop.hdfs.HAUtilClient; |
| import org.apache.hadoop.hdfs.protocol.ClientProtocol; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| /** |
| * Extends {@link ObserverReadProxyProvider} to support NameNode IP failover. |
| * |
| * For Observer reads a client needs to know physical addresses of all |
| * NameNodes, so that it could switch between active and observer nodes |
| * for write and read requests. |
| * |
| * Traditional {@link IPFailoverProxyProvider} works with a virtual |
| * address of the NameNode. If active NameNode fails the virtual address |
| * is assigned to the standby NameNode, and IPFailoverProxyProvider, which |
| * keeps talking to the same virtual address is in fact now connects to |
| * the new physical server. |
| * |
| * To combine these behaviors ObserverReadProxyProviderWithIPFailover |
| * should both |
| * <ol> |
| * <li> Maintain all physical addresses of NameNodes in order to allow |
| * observer reads, and |
| * <li> Should rely on the virtual address of the NameNode in order to |
| * perform failover by assuming that the virtual address always points |
| * to the active NameNode. |
| * </ol> |
| * |
| * An example of a configuration to leverage |
| * ObserverReadProxyProviderWithIPFailover |
| * should include the following values: |
| * <pre>{@code |
| * fs.defaultFS = hdfs://mycluster |
| * dfs.nameservices = mycluster |
| * dfs.ha.namenodes.mycluster = ha1,ha2 |
| * dfs.namenode.rpc-address.mycluster.ha1 = nn01-ha1.com:8020 |
| * dfs.namenode.rpc-address.mycluster.ha2 = nn01-ha2.com:8020 |
| * dfs.client.failover.ipfailover.virtual-address.mycluster = |
| * hdfs://nn01.com:8020 |
| * dfs.client.failover.proxy.provider.mycluster = |
| * org.apache...ObserverReadProxyProviderWithIPFailover |
| * }</pre> |
| * Here {@code nn01.com:8020} is the virtual address of the active NameNode, |
| * while {@code nn01-ha1.com:8020} and {@code nn01-ha2.com:8020} |
| * are the physically addresses the two NameNodes. |
| * |
| * With this configuration, client will use |
| * ObserverReadProxyProviderWithIPFailover, which creates proxies for both |
| * nn01-ha1 and nn01-ha2, used for read/write RPC calls, but for the failover, |
| * it relies on the virtual address nn01.com |
| */ |
| @InterfaceAudience.Private |
| @InterfaceStability.Evolving |
| public class ObserverReadProxyProviderWithIPFailover<T extends ClientProtocol> |
| extends ObserverReadProxyProvider<T> { |
| private static final Logger LOG = LoggerFactory.getLogger( |
| ObserverReadProxyProviderWithIPFailover.class); |
| |
| private static final String IPFAILOVER_CONFIG_PREFIX = |
| HdfsClientConfigKeys.Failover.PREFIX + "ipfailover.virtual-address"; |
| |
| /** |
| * By default ObserverReadProxyProviderWithIPFailover |
| * uses {@link IPFailoverProxyProvider} for failover. |
| */ |
| public ObserverReadProxyProviderWithIPFailover( |
| Configuration conf, URI uri, Class<T> xface, HAProxyFactory<T> factory) { |
| this(conf, uri, xface, factory, |
| new IPFailoverProxyProvider<>(conf, |
| getFailoverVirtualIP(conf, uri.getHost()), xface, factory)); |
| } |
| |
| @Override |
| public boolean useLogicalURI() { |
| return true; |
| } |
| |
| public ObserverReadProxyProviderWithIPFailover( |
| Configuration conf, URI uri, Class<T> xface, HAProxyFactory<T> factory, |
| AbstractNNFailoverProxyProvider<T> failoverProxy) { |
| super(conf, uri, xface, factory, failoverProxy); |
| cloneDelegationTokenForVirtualIP(conf, uri); |
| } |
| |
| /** |
| * Clone delegation token for the virtual IP. Specifically |
| * clone the dt that corresponds to the name service uri, |
| * to the configured corresponding virtual IP. |
| * |
| * @param conf configuration |
| * @param haURI the ha uri, a name service id in this case. |
| */ |
| private void cloneDelegationTokenForVirtualIP( |
| Configuration conf, URI haURI) { |
| URI virtualIPURI = getFailoverVirtualIP(conf, haURI.getHost()); |
| InetSocketAddress vipAddress = new InetSocketAddress( |
| virtualIPURI.getHost(), virtualIPURI.getPort()); |
| HAUtilClient.cloneDelegationTokenForLogicalUri( |
| ugi, haURI, Collections.singleton(vipAddress)); |
| } |
| |
| private static URI getFailoverVirtualIP( |
| Configuration conf, String nameServiceID) { |
| String configKey = IPFAILOVER_CONFIG_PREFIX + "." + nameServiceID; |
| String virtualIP = conf.get(configKey); |
| LOG.info("Name service ID {} will use virtual IP {} for failover", |
| nameServiceID, virtualIP); |
| if (virtualIP == null) { |
| throw new IllegalArgumentException("Virtual IP for failover not found," |
| + "misconfigured " + configKey + "?"); |
| } |
| return URI.create(virtualIP); |
| } |
| } |