org.apache.hadoop.hdfs.server.namenode.ha.IPFailoverProxyProvider Maven / Gradle / Ivy
/**
* 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 org.apache.hadoop.shaded.com.liance
* with the License. You may obtain a copy of the License at
*
* http://www.apache.org.apache.hadoop.shaded.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.shaded.org.apache.hadoop.hdfs.server.namenode.ha;
import java.org.apache.hadoop.shaded.io.Closeable;
import java.org.apache.hadoop.shaded.io.IOException;
import java.org.apache.hadoop.shaded.net.URI;
import org.apache.hadoop.shaded.org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.shaded.org.apache.hadoop.hdfs.DFSUtilClient;
import org.apache.hadoop.shaded.org.apache.hadoop.ipc.RPC;
/**
* A NNFailoverProxyProvider implementation which works on IP failover setup.
* Only one proxy is used to connect to both servers and switching between
* the servers is done by the environment/infrastructure, which guarantees
* clients can consistently reach only one node at a time.
*
* Clients with a live connection will likely get connection reset after an
* IP failover. This case will be handled by the
* FailoverOnNetworkExceptionRetry retry policy. I.e. if the call is
* not idempotent, it won't get retried.
*
* A connection reset while setting up a connection (i.e. before sending a
* request) will be handled in ipc client.
*
* The namenode URI must contain a resolvable host name.
*/
public class IPFailoverProxyProvider extends
AbstractNNFailoverProxyProvider {
private final NNProxyInfo nnProxyInfo;
public IPFailoverProxyProvider(Configuration conf, URI uri,
Class xface, HAProxyFactory factory) {
super(conf, uri, xface, factory);
this.nnProxyInfo = new NNProxyInfo<>(DFSUtilClient.getNNAddress(uri));
}
@Override
public synchronized NNProxyInfo getProxy() {
// Create a non-ha proxy if not already created.
return createProxyIfNeeded(nnProxyInfo);
}
/** Nothing to do for IP failover */
@Override
public void performFailover(T currentProxy) {
}
/**
* Close the proxy,
*/
@Override
public synchronized void close() throws IOException {
if (nnProxyInfo.proxy == null) {
return;
}
if (nnProxyInfo.proxy instanceof Closeable) {
((Closeable)nnProxyInfo.proxy).close();
} else {
RPC.stopProxy(nnProxyInfo.proxy);
}
}
/**
* Logical URI is not used for IP failover.
*/
@Override
public boolean useLogicalURI() {
return false;
}
}