HADOOP-14309. Add PowerShell NodeFencer. Contributed by Inigo Goiri

This commit is contained in:
Chris Douglas 2017-04-27 16:09:28 -07:00
parent 94607214ce
commit 31cf480d65
2 changed files with 156 additions and 1 deletions

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@ -69,7 +69,8 @@ public class NodeFencer {
private static final Map<String, Class<? extends FenceMethod>> STANDARD_METHODS =
ImmutableMap.<String, Class<? extends FenceMethod>>of(
"shell", ShellCommandFencer.class,
"sshfence", SshFenceByTcpPort.class);
"sshfence", SshFenceByTcpPort.class,
"powershell", PowerShellFencer.class);
private final List<FenceMethodWithArg> methods;

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@ -0,0 +1,154 @@
/**
* 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.ha;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStreamWriter;
import java.net.InetSocketAddress;
import java.nio.charset.StandardCharsets;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.hadoop.conf.Configured;
import org.apache.hadoop.util.StringUtils;
/**
* Fencer method that uses PowerShell to remotely connect to a machine and kill
* the required process. This only works in Windows.
*
* The argument passed to this fencer should be a unique string in the
* "CommandLine" attribute for the "java.exe" process. For example, the full
* path for the Namenode: "org.apache.hadoop.hdfs.server.namenode.NameNode".
* The administrator can also shorten the name to "Namenode" if it's unique.
*/
public class PowerShellFencer extends Configured implements FenceMethod {
private static final Log LOG = LogFactory.getLog(PowerShellFencer.class);
@Override
public void checkArgs(String argStr) throws BadFencingConfigurationException {
LOG.info("The parameter for the PowerShell fencer is " + argStr);
}
@Override
public boolean tryFence(HAServiceTarget target, String argsStr)
throws BadFencingConfigurationException {
String processName = argsStr;
InetSocketAddress serviceAddr = target.getAddress();
String hostname = serviceAddr.getHostName();
// Use PowerShell to kill a remote process
String ps1script = buildPSScript(processName, hostname);
if (ps1script == null) {
LOG.error("Cannot build PowerShell script");
return false;
}
// Execute PowerShell script
LOG.info("Executing " + ps1script);
ProcessBuilder builder = new ProcessBuilder("powershell.exe", ps1script);
Process p = null;
try {
p = builder.start();
p.getOutputStream().close();
} catch (IOException e) {
LOG.warn("Unable to execute " + ps1script, e);
return false;
}
// Pump logs to stderr
StreamPumper errPumper = new StreamPumper(
LOG, "fencer", p.getErrorStream(), StreamPumper.StreamType.STDERR);
errPumper.start();
StreamPumper outPumper = new StreamPumper(
LOG, "fencer", p.getInputStream(), StreamPumper.StreamType.STDOUT);
outPumper.start();
// Waiting for the process to finish
int rc = 0;
try {
rc = p.waitFor();
errPumper.join();
outPumper.join();
} catch (InterruptedException ie) {
LOG.warn("Interrupted while waiting for fencing command: " + ps1script);
return false;
}
return rc == 0;
}
/**
* Build a PowerShell script to kill a java.exe process in a remote machine.
*
* @param processName Name of the process to kill. This is an attribute in
* CommandLine.
* @param host Host where the process is.
* @return Path of the PowerShell script.
*/
private String buildPSScript(final String processName, final String host) {
LOG.info(
"Building PowerShell script to kill " + processName + " at " + host);
String ps1script = null;
BufferedWriter writer = null;
try {
File file = File.createTempFile("temp-fence-command", ".ps1");
file.deleteOnExit();
FileOutputStream fos = new FileOutputStream(file, false);
OutputStreamWriter osw =
new OutputStreamWriter(fos, StandardCharsets.UTF_8);
writer = new BufferedWriter(osw);
// Filter to identify the Namenode process
String filter = StringUtils.join(" and ", new String[] {
"Name LIKE '%java.exe%'",
"CommandLine LIKE '%" + processName+ "%'"});
// Identify the process
String cmd = "Get-WmiObject Win32_Process";
cmd += " -Filter \"" + filter + "\"";
// Remote location
cmd += " -Computer " + host;
// Kill it
cmd += " |% { $_.Terminate() }";
LOG.info("PowerShell command: " + cmd);
writer.write(cmd);
writer.flush();
ps1script = file.getAbsolutePath();
} catch (IOException ioe) {
LOG.error("Cannot create PowerShell script", ioe);
} finally {
if (writer != null) {
try {
writer.close();
} catch (IOException ioe) {
LOG.error("Cannot close PowerShell script", ioe);
}
}
}
return ps1script;
}
}