/**
* 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.flume.sink.hdfs;
import java.io.File;
import java.io.IOException;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Calendar;
import java.util.HashMap;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Map.Entry;
import java.util.TimeZone;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.ScheduledExecutorService;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicReference;
import org.apache.flume.Channel;
import org.apache.flume.Clock;
import org.apache.flume.Context;
import org.apache.flume.Event;
import org.apache.flume.EventDeliveryException;
import org.apache.flume.SystemClock;
import org.apache.flume.Transaction;
import org.apache.flume.conf.Configurable;
import org.apache.flume.formatter.output.BucketPath;
import org.apache.flume.instrumentation.SinkCounter;
import org.apache.flume.sink.AbstractSink;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.io.SequenceFile.CompressionType;
import org.apache.hadoop.io.compress.CompressionCodec;
import org.apache.hadoop.io.compress.CompressionCodecFactory;
import org.apache.hadoop.security.SecurityUtil;
import org.apache.hadoop.security.UserGroupInformation;
import org.apache.hadoop.security.UserGroupInformation.AuthenticationMethod;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import com.google.common.collect.Lists;
import com.google.common.util.concurrent.ThreadFactoryBuilder;
public class HDFSEventSink extends AbstractSink implements Configurable {
public interface WriterCallback {
public void run(String filePath);
}
private static final Logger LOG = LoggerFactory
.getLogger(HDFSEventSink.class);
private static String DIRECTORY_DELIMITER = System.getProperty("file.separator");
private static final long defaultRollInterval = 30;
private static final long defaultRollSize = 1024;
private static final long defaultRollCount = 10;
private static final String defaultFileName = "FlumeData";
private static final String defaultSuffix = "";
private static final String defaultInUsePrefix = "";
private static final String defaultInUseSuffix = ".tmp";
private static final long defaultBatchSize = 100;
private static final String defaultFileType = HDFSWriterFactory.SequenceFileType;
private static final int defaultMaxOpenFiles = 5000;
/**
* Default length of time we wait for blocking BucketWriter calls
* before timing out the operation. Intended to prevent server hangs.
*/
private static final long defaultCallTimeout = 10000;
/**
* Default number of threads available for tasks
* such as append/open/close/flush with hdfs.
* These tasks are done in a separate thread in
* the case that they take too long. In which
* case we create a new file and move on.
*/
private static final int defaultThreadPoolSize = 10;
private static final int defaultRollTimerPoolSize = 1;
/**
* Singleton credential manager that manages static credentials for the
* entire JVM
*/
private static final AtomicReference<KerberosUser> staticLogin
= new AtomicReference<KerberosUser>();
private final HDFSWriterFactory writerFactory;
private WriterLinkedHashMap sfWriters;
private long rollInterval;
private long rollSize;
private long rollCount;
private long batchSize;
private int threadsPoolSize;
private int rollTimerPoolSize;
private CompressionCodec codeC;
private CompressionType compType;
private String fileType;
private String filePath;
private String fileName;
private String suffix;
private String inUsePrefix;
private String inUseSuffix;
private TimeZone timeZone;
private int maxOpenFiles;
private ExecutorService callTimeoutPool;
private ScheduledExecutorService timedRollerPool;
private String kerbConfPrincipal;
private String kerbKeytab;
private String proxyUserName;
private UserGroupInformation proxyTicket;
private boolean needRounding = false;
private int roundUnit = Calendar.SECOND;
private int roundValue = 1;
private boolean useLocalTime = false;
private long callTimeout;
private Context context;
private SinkCounter sinkCounter;
private volatile int idleTimeout;
private Clock clock;
private SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMddHH");
private boolean switchon = true;
//stat
private static long STAT_EVENT_COUNT_THRESHOLD = 100000;
private long statEventCount = 0;
private long statTakeTime = 0;
private long statAppendTime = 0;
private long statSyncTime = 0;
private long statAllTime = 0;
/*
* Extended Java LinkedHashMap for open file handle LRU queue.
* We want to clear the oldest file handle if there are too many open ones.
*/
private static class WriterLinkedHashMap
extends LinkedHashMap<String, BucketWriter> {
private final int maxOpenFiles;
public WriterLinkedHashMap(int maxOpenFiles) {
super(16, 0.75f, true); // stock initial capacity/load, access ordering
this.maxOpenFiles = maxOpenFiles;
}
@Override
protected boolean removeEldestEntry(Entry<String, BucketWriter> eldest) {
if (size() > maxOpenFiles) {
// If we have more that max open files, then close the last one and
// return true
try {
eldest.getValue().close();
} catch (IOException e) {
LOG.warn(eldest.getKey().toString(), e);
} catch (InterruptedException e) {
LOG.warn(eldest.getKey().toString(), e);
Thread.currentThread().interrupt();
}
return true;
} else {
return false;
}
}
}
public HDFSEventSink() {
this(new HDFSWriterFactory());
}
public HDFSEventSink(HDFSWriterFactory writerFactory) {
this.writerFactory = writerFactory;
}
// read configuration and setup thresholds
@Override
public void configure(Context context) {
this.context = context;
filePath = Preconditions.checkNotNull(
context.getString("hdfs.path"), "hdfs.path is required");
fileName = context.getString("hdfs.filePrefix", defaultFileName);
this.suffix = context.getString("hdfs.fileSuffix", defaultSuffix);
inUsePrefix = context.getString("hdfs.inUsePrefix", defaultInUsePrefix);
inUseSuffix = context.getString("hdfs.inUseSuffix", defaultInUseSuffix);
String tzName = context.getString("hdfs.timeZone");
timeZone = tzName == null ? null : TimeZone.getTimeZone(tzName);
rollInterval = context.getLong("hdfs.rollInterval", defaultRollInterval);
rollSize = context.getLong("hdfs.rollSize", defaultRollSize);
rollCount = context.getLong("hdfs.rollCount", defaultRollCount);
batchSize = context.getLong("hdfs.batchSize", defaultBatchSize);
idleTimeout = context.getInteger("hdfs.idleTimeout", 0);
String codecName = context.getString("hdfs.codeC");
fileType = context.getString("hdfs.fileType", defaultFileType);
maxOpenFiles = context.getInteger("hdfs.maxOpenFiles", defaultMaxOpenFiles);
callTimeout = context.getLong("hdfs.callTimeout", defaultCallTimeout);
threadsPoolSize = context.getInteger("hdfs.threadsPoolSize",
defaultThreadPoolSize);
rollTimerPoolSize = context.getInteger("hdfs.rollTimerPoolSize",
defaultRollTimerPoolSize);
kerbConfPrincipal = context.getString("hdfs.kerberosPrincipal", "");
kerbKeytab = context.getString("hdfs.kerberosKeytab", "");
proxyUserName = context.getString("hdfs.proxyUser", "");
Preconditions.checkArgument(batchSize > 0,
"batchSize must be greater than 0");
if (codecName == null) {
codeC = null;
compType = CompressionType.NONE;
} else {
codeC = getCodec(codecName);
// TODO : set proper compression type
compType = CompressionType.BLOCK;
}
// Do not allow user to set fileType DataStream with codeC together
// To prevent output file with compress extension (like .snappy)
if(fileType.equalsIgnoreCase(HDFSWriterFactory.DataStreamType)
&& codecName != null) {
throw new IllegalArgumentException("fileType: " + fileType +
" which does NOT support compressed output. Please don't set codeC" +
" or change the fileType if compressed output is desired.");
}
if(fileType.equalsIgnoreCase(HDFSWriterFactory.CompStreamType)) {
Preconditions.checkNotNull(codeC, "It's essential to set compress codec"
+ " when fileType is: " + fileType);
}
if (!authenticate()) {
LOG.error("Failed to authenticate!");
}
needRounding = context.getBoolean("hdfs.round", false);
if(needRounding) {
String unit = context.getString("hdfs.roundUnit", "second");
if (unit.equalsIgnoreCase("hour")) {
this.roundUnit = Calendar.HOUR_OF_DAY;
} else if (unit.equalsIgnoreCase("minute")) {
this.roundUnit = Calendar.MINUTE;
} else if (unit.equalsIgnoreCase("second")){
this.roundUnit = Calendar.SECOND;
} else {
LOG.warn("Rounding unit is not valid, please set one of" +
"minute, hour, or second. Rounding will be disabled");
needRounding = false;
}
this.roundValue = context.getInteger("hdfs.roundValue", 1);
if(roundUnit == Calendar.SECOND || roundUnit == Calendar.MINUTE){
Preconditions.checkArgument(roundValue > 0 && roundValue <= 60,
"Round value" +
"must be > 0 and <= 60");
} else if (roundUnit == Calendar.HOUR_OF_DAY){
Preconditions.checkArgument(roundValue > 0 && roundValue <= 24,
"Round value" +
"must be > 0 and <= 24");
}
}
this.useLocalTime = context.getBoolean("hdfs.useLocalTimeStamp", false);
if(useLocalTime) {
clock = new SystemClock();
}
if (sinkCounter == null) {
sinkCounter = new SinkCounter(getName());
}
this.switchon = context.getBoolean("switchon", true);
}
private static boolean codecMatches(Class<? extends CompressionCodec> cls,
String codecName) {
String simpleName = cls.getSimpleName();
if (cls.getName().equals(codecName)
|| simpleName.equalsIgnoreCase(codecName)) {
return true;
}
if (simpleName.endsWith("Codec")) {
String prefix = simpleName.substring(0,
simpleName.length() - "Codec".length());
if (prefix.equalsIgnoreCase(codecName)) {
return true;
}
}
return false;
}
@VisibleForTesting
static CompressionCodec getCodec(String codecName) {
Configuration conf = new Configuration();
List<Class<? extends CompressionCodec>> codecs = CompressionCodecFactory
.getCodecClasses(conf);
// Wish we could base this on DefaultCodec but appears not all codec's
// extend DefaultCodec(Lzo)
CompressionCodec codec = null;
ArrayList<String> codecStrs = new ArrayList<String>();
codecStrs.add("None");
for (Class<? extends CompressionCodec> cls : codecs) {
codecStrs.add(cls.getSimpleName());
if (codecMatches(cls, codecName)) {
try {
codec = cls.newInstance();
} catch (InstantiationException e) {
LOG.error("Unable to instantiate " + cls + " class");
} catch (IllegalAccessException e) {
LOG.error("Unable to access " + cls + " class");
}
}
}
if (codec == null) {
if (!codecName.equalsIgnoreCase("None")) {
throw new IllegalArgumentException("Unsupported compression codec "
+ codecName + ". Please choose from: " + codecStrs);
}
} else if (codec instanceof org.apache.hadoop.conf.Configurable) {
// Must check instanceof codec as BZip2Codec doesn't inherit Configurable
// Must set the configuration for Configurable objects that may or do use
// native libs
((org.apache.hadoop.conf.Configurable) codec).setConf(conf);
}
return codec;
}
/**
* Pull events out of channel and send it to HDFS. Take at most batchSize
* events per Transaction. Find the corresponding bucket for the event.
* Ensure the file is open. Serialize the data and write it to the file on
* HDFS. <br/>
* This method is not thread safe.
*/
public Status process() throws EventDeliveryException {
//if sink is switch off, then just return
if ( !this.switchon ) {
LOG.warn("HdfsSink is set off, just return.");
try {
Thread.sleep(500);
} catch (InterruptedException e) {
}
return Status.READY;
}
long t1 = System.currentTimeMillis();
long t2 = System.currentTimeMillis();
long tStart = t1;
long tEnd = t1;
Channel channel = getChannel();
Transaction transaction = channel.getTransaction();
List<BucketWriter> writers = Lists.newArrayList();
Map<String, HDFSEventSinkMetric> metricMap = new HashMap<String, HDFSEventSinkMetric>();
Map<BucketWriter, String> bucketWriter2Category = new HashMap<BucketWriter, String>();
transaction.begin();
long getFilenameTime = 0;
try {
int txnEventCount = 0;
for (txnEventCount = 0; txnEventCount < batchSize; txnEventCount++) {
tStart = System.currentTimeMillis(); //stat start
Event event = channel.take();
tEnd = System.currentTimeMillis(); //stat end
statTakeTime += tEnd - tStart;
if (event == null) {
break;
}
String category = event.getHeaders().get("category");
HDFSEventSinkMetric crtMetric = metricMap.get(category);
if(crtMetric == null){
crtMetric = new HDFSEventSinkMetric(category);
metricMap.put(category, crtMetric);
}
crtMetric.incTake(tEnd - tStart);
crtMetric.incEventNum(1);
tStart = System.currentTimeMillis();
// reconstruct the path name by substituting place holders
/*
String realPath = BucketPath.escapeString(filePath, event.getHeaders(),
timeZone, needRounding, roundUnit, roundValue, useLocalTime);
String realName = BucketPath.escapeString(fileName, event.getHeaders(),
timeZone, needRounding, roundUnit, roundValue, useLocalTime);
*/
// path /user/hive/warehouse/originallog.db/%{category}org/dt=%Y%m%d/hour=%H
String realPath = BucketPath.getMeiTuanHadoopLogPath(filePath, event.getHeaders().get("category"), timeZone);
// filePrefix if fixed, just use it
String realName = fileName;
getFilenameTime += System.currentTimeMillis() - tStart;
String lookupPath = realPath + DIRECTORY_DELIMITER + realName;
BucketWriter bucketWriter = sfWriters.get(lookupPath);
// we haven't seen this file yet, so open it and cache the handle
if (bucketWriter == null) {
HDFSWriter hdfsWriter = writerFactory.getWriter(fileType);
WriterCallback idleCallback = null;
if(idleTimeout != 0) {
idleCallback = new WriterCallback() {
@Override
public void run(String bucketPath) {
sfWriters.remove(bucketPath);
}
};
}
bucketWriter = new BucketWriter(rollInterval, rollSize, rollCount,
batchSize, context, realPath, realName, inUsePrefix, inUseSuffix,
suffix, codeC, compType, hdfsWriter, timedRollerPool,
proxyTicket, sinkCounter, idleTimeout, idleCallback,
lookupPath, callTimeout, callTimeoutPool);
sfWriters.put(lookupPath, bucketWriter);
}
// track the buckets getting written in this transaction
if (!writers.contains(bucketWriter)) {
writers.add(bucketWriter);
bucketWriter2Category.put(bucketWriter, category);
}
// Write the data to HDFS
tStart = System.currentTimeMillis(); //stat start
bucketWriter.append(event);
tEnd = System.currentTimeMillis(); //stat end
statAppendTime += tEnd - tStart;
crtMetric.incAppend(tEnd - tStart);
}
if (txnEventCount == 0) {
sinkCounter.incrementBatchEmptyCount();
} else if (txnEventCount == batchSize) {
sinkCounter.incrementBatchCompleteCount();
} else {
sinkCounter.incrementBatchUnderflowCount();
}
statEventCount += txnEventCount;
// flush all pending buckets before committing the transaction
tStart = System.currentTimeMillis(); //stat start
for (BucketWriter bucketWriter : writers) {
long begin = System.currentTimeMillis();
bucketWriter.flush();
long end = System.currentTimeMillis();
String category = bucketWriter2Category.get(bucketWriter);
HDFSEventSinkMetric crtMetric = metricMap.get(category);
if(crtMetric != null){
crtMetric.incSync(end - begin);
}else{
LOG.error("bucketWriter2Category has no entry for : " + bucketWriter.toString());
}
}
tEnd = System.currentTimeMillis(); //stat end
statSyncTime += tEnd - tStart;
transaction.commit();
t2 = System.currentTimeMillis();
statAllTime += t2 - t1;
//print stat info
if (statEventCount > 0) {
LOG.info("HdfsSink-TIME-STAT sink[" + this.getName()
+ "] writers[" + writers.size()
+ "] eventcount[" + statEventCount
+ "] all[" + statAllTime
+ "] take[" + statTakeTime
+ "] append[" + statAppendTime
+ "] sync[" + statSyncTime
+ "] getFilenameTime[" + getFilenameTime + "]");
for(Map.Entry<String, HDFSEventSinkMetric> crtEntry : metricMap.entrySet()){
HDFSEventSinkMetric crtMetric = crtEntry.getValue();
crtMetric.sum();
LOG.info("HdfsSink-TIME-STAT sink[" + this.getName() + "] " + crtMetric.toString());
}
}
statEventCount = 0;
statAllTime = 0;
statTakeTime = 0;
statAppendTime = 0;
statSyncTime = 0;
if (txnEventCount < 1) {
return Status.BACKOFF;
} else {
sinkCounter.addToEventDrainSuccessCount(txnEventCount);
return Status.READY;
}
} catch (IOException eIO) {
transaction.rollback();
LOG.warn("HDFS IO error", eIO);
return Status.BACKOFF;
} catch (Throwable th) {
transaction.rollback();
LOG.error("process failed", th);
if (th instanceof Error) {
throw (Error) th;
} else {
throw new EventDeliveryException(th);
}
} finally {
transaction.close();
}
}
@Override
public void stop() {
// do not constrain close() calls with a timeout
for (Entry<String, BucketWriter> entry : sfWriters.entrySet()) {
LOG.info("Closing {}", entry.getKey());
try {
// cancel the idle callback
entry.getValue().close(true);
} catch (Exception ex) {
LOG.warn("Exception while closing " + entry.getKey() + ". " +
"Exception follows.", ex);
if (ex instanceof InterruptedException) {
Thread.currentThread().interrupt();
}
}
}
// shut down all our thread pools
ExecutorService toShutdown[] = {callTimeoutPool, timedRollerPool};
for (ExecutorService execService : toShutdown) {
execService.shutdown();
try {
while (execService.isTerminated() == false) {
execService.awaitTermination(
Math.max(defaultCallTimeout, callTimeout), TimeUnit.MILLISECONDS);
}
} catch (InterruptedException ex) {
LOG.warn("shutdown interrupted on " + execService, ex);
}
}
callTimeoutPool = null;
timedRollerPool = null;
sfWriters.clear();
sfWriters = null;
sinkCounter.stop();
super.stop();
}
@Override
public void start() {
String timeoutName = "hdfs-" + getName() + "-call-runner-%d";
callTimeoutPool = Executors.newFixedThreadPool(threadsPoolSize,
new ThreadFactoryBuilder().setNameFormat(timeoutName).build());
String rollerName = "hdfs-" + getName() + "-roll-timer-%d";
timedRollerPool = Executors.newScheduledThreadPool(rollTimerPoolSize,
new ThreadFactoryBuilder().setNameFormat(rollerName).build());
this.sfWriters = new WriterLinkedHashMap(maxOpenFiles);
sinkCounter.start();
super.start();
}
private boolean authenticate() {
// logic for kerberos login
boolean useSecurity = UserGroupInformation.isSecurityEnabled();
LOG.info("Hadoop Security enabled: " + useSecurity);
if (useSecurity) {
// sanity checking
if (kerbConfPrincipal.isEmpty()) {
LOG.error("Hadoop running in secure mode, but Flume config doesn't "
+ "specify a principal to use for Kerberos auth.");
return false;
}
if (kerbKeytab.isEmpty()) {
LOG.error("Hadoop running in secure mode, but Flume config doesn't "
+ "specify a keytab to use for Kerberos auth.");
return false;
} else {
//If keytab is specified, user should want it take effect.
//HDFSEventSink will halt when keytab file is non-exist or unreadable
File kfile = new File(kerbKeytab);
if (!(kfile.isFile() && kfile.canRead())) {
throw new IllegalArgumentException("The keyTab file: "
+ kerbKeytab + " is nonexistent or can't read. "
+ "Please specify a readable keytab file for Kerberos auth.");
}
}
String principal;
try {
// resolves _HOST pattern using standard Hadoop search/replace
// via DNS lookup when 2nd argument is empty
principal = SecurityUtil.getServerPrincipal(kerbConfPrincipal, "");
} catch (IOException e) {
LOG.error("Host lookup error resolving kerberos principal ("
+ kerbConfPrincipal + "). Exception follows.", e);
return false;
}
Preconditions.checkNotNull(principal, "Principal must not be null");
KerberosUser prevUser = staticLogin.get();
KerberosUser newUser = new KerberosUser(principal, kerbKeytab);
// be cruel and unusual when user tries to login as multiple principals
// this isn't really valid with a reconfigure but this should be rare
// enough to warrant a restart of the agent JVM
// TODO: find a way to interrogate the entire current config state,
// since we don't have to be unnecessarily protective if they switch all
// HDFS sinks to use a different principal all at once.
Preconditions.checkState(prevUser == null || prevUser.equals(newUser),
"Cannot use multiple kerberos principals in the same agent. " +
" Must restart agent to use new principal or keytab. " +
"Previous = %s, New = %s", prevUser, newUser);
// attempt to use cached credential if the user is the same
// this is polite and should avoid flooding the KDC with auth requests
UserGroupInformation curUser = null;
if (prevUser != null && prevUser.equals(newUser)) {
try {
curUser = UserGroupInformation.getLoginUser();
} catch (IOException e) {
LOG.warn("User unexpectedly had no active login. Continuing with " +
"authentication", e);
}
}
if (curUser == null || !curUser.getUserName().equals(principal)) {
try {
// static login
kerberosLogin(this, principal, kerbKeytab);
} catch (IOException e) {
LOG.error("Authentication or file read error while attempting to "
+ "login as kerberos principal (" + principal + ") using "
+ "keytab (" + kerbKeytab + "). Exception follows.", e);
return false;
}
} else {
LOG.debug("{}: Using existing principal login: {}", this, curUser);
}
// we supposedly got through this unscathed... so store the static user
staticLogin.set(newUser);
}
// hadoop impersonation works with or without kerberos security
proxyTicket = null;
if (!proxyUserName.isEmpty()) {
try {
proxyTicket = UserGroupInformation.createProxyUser(
proxyUserName, UserGroupInformation.getLoginUser());
} catch (IOException e) {
LOG.error("Unable to login as proxy user. Exception follows.", e);
return false;
}
}
UserGroupInformation ugi = null;
if (proxyTicket != null) {
ugi = proxyTicket;
} else if (useSecurity) {
try {
ugi = UserGroupInformation.getLoginUser();
} catch (IOException e) {
LOG.error("Unexpected error: Unable to get authenticated user after " +
"apparent successful login! Exception follows.", e);
return false;
}
}
if (ugi != null) {
// dump login information
AuthenticationMethod authMethod = ugi.getAuthenticationMethod();
LOG.info("Auth method: {}", authMethod);
LOG.info(" User name: {}", ugi.getUserName());
LOG.info(" Using keytab: {}", ugi.isFromKeytab());
if (authMethod == AuthenticationMethod.PROXY) {
UserGroupInformation superUser;
try {
superUser = UserGroupInformation.getLoginUser();
LOG.info(" Superuser auth: {}", superUser.getAuthenticationMethod());
LOG.info(" Superuser name: {}", superUser.getUserName());
LOG.info(" Superuser using keytab: {}", superUser.isFromKeytab());
} catch (IOException e) {
LOG.error("Unexpected error: unknown superuser impersonating proxy.",
e);
return false;
}
}
LOG.info("Logged in as user {}", ugi.getUserName());
return true;
}
return true;
}
/**
* Static synchronized method for static Kerberos login. <br/>
* Static synchronized due to a thundering herd problem when multiple Sinks
* attempt to log in using the same principal at the same time with the
* intention of impersonating different users (or even the same user).
* If this is not controlled, MIT Kerberos v5 believes it is seeing a replay
* attach and it returns:
* <blockquote>Request is a replay (34) - PROCESS_TGS</blockquote>
* In addition, since the underlying Hadoop APIs we are using for
* impersonation are static, we define this method as static as well.
*
* @param principal
* Fully-qualified principal to use for authentication.
* @param keytab
* Location of keytab file containing credentials for principal.
* @return Logged-in user
* @throws IOException
* if login fails.
*/
private static synchronized UserGroupInformation kerberosLogin(
HDFSEventSink sink, String principal, String keytab) throws IOException {
// if we are the 2nd user thru the lock, the login should already be
// available statically if login was successful
UserGroupInformation curUser = null;
try {
curUser = UserGroupInformation.getLoginUser();
} catch (IOException e) {
// not a big deal but this shouldn't typically happen because it will
// generally fall back to the UNIX user
LOG.debug("Unable to get login user before Kerberos auth attempt.", e);
}
// we already have logged in successfully
if (curUser != null && curUser.getUserName().equals(principal)) {
LOG.debug("{}: Using existing principal ({}): {}",
new Object[]{sink, principal, curUser});
// no principal found
} else {
LOG.info("{}: Attempting kerberos login as principal ({}) from keytab " +
"file ({})", new Object[]{sink, principal, keytab});
// attempt static kerberos login
UserGroupInformation.loginUserFromKeytab(principal, keytab);
curUser = UserGroupInformation.getLoginUser();
}
return curUser;
}
@Override
public String toString() {
return "{ Sink type:" + getClass().getSimpleName() + ", name:" + getName() +
" }";
}
@VisibleForTesting
void setBucketClock(Clock clock) {
BucketPath.setClock(clock);
}
}