org.apache.hadoop.registry.server.services.MicroZookeeperService Maven / Gradle / Ivy
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* Licensed to the Apache Software Foundation (ASF) under one
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* 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.registry.server.services;
import com.google.common.base.Preconditions;
import org.apache.commons.lang3.StringUtils;
import org.apache.curator.ensemble.fixed.FixedEnsembleProvider;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileUtil;
import org.apache.hadoop.service.AbstractService;
import org.apache.hadoop.registry.client.api.RegistryConstants;
import org.apache.hadoop.registry.client.impl.zk.BindingInformation;
import org.apache.hadoop.registry.client.impl.zk.RegistryBindingSource;
import org.apache.hadoop.registry.client.impl.zk.RegistryInternalConstants;
import org.apache.hadoop.registry.client.impl.zk.RegistrySecurity;
import org.apache.hadoop.registry.client.impl.zk.ZookeeperConfigOptions;
import org.apache.zookeeper.server.ServerCnxnFactory;
import org.apache.zookeeper.server.ZooKeeperServer;
import org.apache.zookeeper.server.persistence.FileTxnSnapLog;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.io.File;
import java.io.IOException;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.net.InetSocketAddress;
import java.net.ServerSocket;
import java.net.UnknownHostException;
/**
* This is a small, localhost Zookeeper service instance that is contained
* in a YARN service...it's been derived from Apache Twill.
*
* It implements {@link RegistryBindingSource} and provides binding information,
* once started. Until {@link #start()} is called, the hostname and
* port may be undefined. Accordingly, the service raises an exception in this
* condition.
*
* If you wish to chain together a registry service with this one under
* the same {@code CompositeService}, this service must be added
* as a child first.
*
* It also sets the configuration parameter
* {@link RegistryConstants#KEY_REGISTRY_ZK_QUORUM}
* to its connection string. Any code with access to the service configuration
* can view it.
*/
@InterfaceStability.Evolving
public class MicroZookeeperService
extends AbstractService
implements RegistryBindingSource, RegistryConstants,
ZookeeperConfigOptions,
MicroZookeeperServiceKeys{
private static final Logger
LOG = LoggerFactory.getLogger(MicroZookeeperService.class);
private File instanceDir;
private File dataDir;
private int tickTime;
private int port;
private String host;
private boolean secureServer;
private ServerCnxnFactory factory;
private BindingInformation binding;
private File confDir;
private StringBuilder diagnostics = new StringBuilder();
/**
* Create an instance
* @param name service name
*/
public MicroZookeeperService(String name) {
super(name);
}
/**
* Get the connection string.
* @return the string
* @throws IllegalStateException if the connection is not yet valid
*/
public String getConnectionString() {
Preconditions.checkState(factory != null, "service not started");
InetSocketAddress addr = factory.getLocalAddress();
return String.format("%s:%d", addr.getHostName(), addr.getPort());
}
/**
* Get the connection address
* @return the connection as an address
* @throws IllegalStateException if the connection is not yet valid
*/
public InetSocketAddress getConnectionAddress() {
Preconditions.checkState(factory != null, "service not started");
return factory.getLocalAddress();
}
/**
* Create an inet socket addr from the local host + port number
* @param port port to use
* @return a (hostname, port) pair
* @throws UnknownHostException if the server cannot resolve the host
*/
private InetSocketAddress getAddress(int port) throws UnknownHostException {
return new InetSocketAddress(host, port <= 0 ? getRandomAvailablePort() : port);
}
/**
* Initialize the service, including choosing a path for the data
* @param conf configuration
* @throws Exception
*/
@Override
protected void serviceInit(Configuration conf) throws Exception {
port = conf.getInt(KEY_ZKSERVICE_PORT, 0);
tickTime = conf.getInt(KEY_ZKSERVICE_TICK_TIME,
ZooKeeperServer.DEFAULT_TICK_TIME);
String instancedirname = conf.getTrimmed(
KEY_ZKSERVICE_DIR, "");
host = conf.getTrimmed(KEY_ZKSERVICE_HOST, DEFAULT_ZKSERVICE_HOST);
if (instancedirname.isEmpty()) {
File testdir = new File(System.getProperty("test.dir", "target"));
instanceDir = new File(testdir, "zookeeper" + getName());
} else {
instanceDir = new File(instancedirname);
FileUtil.fullyDelete(instanceDir);
}
LOG.debug("Instance directory is {}", instanceDir);
mkdirStrict(instanceDir);
dataDir = new File(instanceDir, "data");
confDir = new File(instanceDir, "conf");
mkdirStrict(dataDir);
mkdirStrict(confDir);
super.serviceInit(conf);
}
/**
* Create a directory, ignoring if the dir is already there,
* and failing if a file or something else was at the end of that
* path
* @param dir dir to guarantee the existence of
* @throws IOException IO problems, or path exists but is not a dir
*/
private void mkdirStrict(File dir) throws IOException {
if (!dir.mkdirs()) {
if (!dir.isDirectory()) {
throw new IOException("Failed to mkdir " + dir);
}
}
}
/**
* Append a formatted string to the diagnostics.
*
* A newline is appended afterwards.
* @param text text including any format commands
* @param args arguments for the forma operation.
*/
protected void addDiagnostics(String text, Object ... args) {
diagnostics.append(String.format(text, args)).append('\n');
}
/**
* Get the diagnostics info
* @return the diagnostics string built up
*/
public String getDiagnostics() {
return diagnostics.toString();
}
/**
* set up security. this must be done prior to creating
* the ZK instance, as it sets up JAAS if that has not been done already.
*
* @return true if the cluster has security enabled.
*/
public boolean setupSecurity() throws IOException {
Configuration conf = getConfig();
String jaasContext = conf.getTrimmed(KEY_REGISTRY_ZKSERVICE_JAAS_CONTEXT);
secureServer = StringUtils.isNotEmpty(jaasContext);
if (secureServer) {
RegistrySecurity.validateContext(jaasContext);
RegistrySecurity.bindZKToServerJAASContext(jaasContext);
// policy on failed auth
System.setProperty(PROP_ZK_ALLOW_FAILED_SASL_CLIENTS,
conf.get(KEY_ZKSERVICE_ALLOW_FAILED_SASL_CLIENTS,
"true"));
//needed so that you can use sasl: strings in the registry
System.setProperty(RegistryInternalConstants.ZOOKEEPER_AUTH_PROVIDER +".1",
RegistryInternalConstants.SASLAUTHENTICATION_PROVIDER);
String serverContext =
System.getProperty(PROP_ZK_SERVER_SASL_CONTEXT);
addDiagnostics("Server JAAS context s = %s", serverContext);
return true;
} else {
return false;
}
}
/**
* Startup: start ZK. It is only after this that
* the binding information is valid.
* @throws Exception
*/
@Override
protected void serviceStart() throws Exception {
setupSecurity();
FileTxnSnapLog ftxn = new FileTxnSnapLog(dataDir, dataDir);
ZooKeeperServer zkServer = new ZooKeeperServer(ftxn, tickTime);
LOG.info("Starting Local Zookeeper service");
factory = ServerCnxnFactory.createFactory();
factory.configure(getAddress(port), -1);
factory.startup(zkServer);
String connectString = getConnectionString();
LOG.info("In memory ZK started at {}\n", connectString);
if (LOG.isDebugEnabled()) {
StringWriter sw = new StringWriter();
PrintWriter pw = new PrintWriter(sw);
zkServer.dumpConf(pw);
pw.flush();
LOG.debug("ZooKeeper config:\n" + sw.toString());
}
binding = new BindingInformation();
binding.ensembleProvider = new FixedEnsembleProvider(connectString);
binding.description =
getName() + " reachable at \"" + connectString + "\"";
addDiagnostics(binding.description);
// finally: set the binding information in the config
getConfig().set(KEY_REGISTRY_ZK_QUORUM, connectString);
}
/**
* When the service is stopped, it deletes the data directory
* and its contents
* @throws Exception
*/
@Override
protected void serviceStop() throws Exception {
if (factory != null) {
factory.shutdown();
factory = null;
}
if (dataDir != null) {
FileUtil.fullyDelete(dataDir);
}
}
@Override
public BindingInformation supplyBindingInformation() {
Preconditions.checkNotNull(binding,
"Service is not started: binding information undefined");
return binding;
}
/**
* Returns with a random open port can be used to set as server port for ZooKeeper.
* @return a random open port or 0 (in case of error)
*/
private int getRandomAvailablePort() {
port = 0;
try {
final ServerSocket s = new ServerSocket(0);
port = s.getLocalPort();
s.close();
} catch (IOException e) {
LOG.warn("ERROR during selecting random port for ZooKeeper server to bind." , e);
}
return port;
}
}