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HDFS-10713. Throttle FsNameSystem lock warnings. Contributed by Hanisha Koneru.

This commit is contained in:
Arpit Agarwal 2016-09-27 09:00:39 -07:00
parent 5bc297c58f
commit a349c54603
2 changed files with 151 additions and 36 deletions
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102
hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java
View File

@ -76,6 +76,8 @@ import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_WRITE_LOCK_REPOR
import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_WRITE_LOCK_REPORTING_THRESHOLD_MS_DEFAULT;
import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_READ_LOCK_REPORTING_THRESHOLD_MS_KEY;
import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_READ_LOCK_REPORTING_THRESHOLD_MS_DEFAULT;
import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_LOCK_SUPPRESS_WARNING_INTERVAL_KEY;
import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_LOCK_SUPPRESS_WARNING_INTERVAL_DEFAULT;
import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_RETRY_CACHE_EXPIRYTIME_MILLIS_DEFAULT;
import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_RETRY_CACHE_EXPIRYTIME_MILLIS_KEY;
import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_RETRY_CACHE_HEAP_PERCENT_DEFAULT;
@ -136,6 +138,8 @@ import java.util.TreeMap;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
import java.util.concurrent.locks.Condition;
import java.util.concurrent.locks.ReentrantLock;
import java.util.concurrent.locks.ReentrantReadWriteLock;
@ -293,6 +297,7 @@ import org.apache.hadoop.util.Daemon;
import org.apache.hadoop.util.DataChecksum;
import org.apache.hadoop.util.ReflectionUtils;
import org.apache.hadoop.util.StringUtils;
import org.apache.hadoop.util.Timer;
import org.apache.hadoop.util.VersionInfo;
import org.apache.log4j.Appender;
import org.apache.log4j.AsyncAppender;
@ -729,6 +734,7 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
fsLock = new FSNamesystemLock(fair);
cond = fsLock.writeLock().newCondition();
cpLock = new ReentrantLock();
setTimer(new Timer());
this.fsImage = fsImage;
try {
@ -845,6 +851,10 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
DFS_NAMENODE_READ_LOCK_REPORTING_THRESHOLD_MS_KEY,
DFS_NAMENODE_READ_LOCK_REPORTING_THRESHOLD_MS_DEFAULT);
this.lockSuppressWarningInterval = conf.getTimeDuration(
DFS_LOCK_SUPPRESS_WARNING_INTERVAL_KEY,
DFS_LOCK_SUPPRESS_WARNING_INTERVAL_DEFAULT, TimeUnit.MILLISECONDS);
// For testing purposes, allow the DT secret manager to be started regardless
// of whether security is enabled.
alwaysUseDelegationTokensForTests = conf.getBoolean(
@ -1509,12 +1519,20 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
return Util.stringCollectionAsURIs(dirNames);
}
private final long lockSuppressWarningInterval;
/** Threshold (ms) for long holding write lock report. */
private long writeLockReportingThreshold;
private final long writeLockReportingThreshold;
private int numWriteLockWarningsSuppressed = 0;
private long timeStampOfLastWriteLockReport = 0;
private long longestWriteLockHeldInterval = 0;
/** Last time stamp for write lock. Keep the longest one for multi-entrance.*/
private long writeLockHeldTimeStamp;
/** Threshold (ms) for long holding read lock report. */
private long readLockReportingThreshold;
private AtomicInteger numReadLockWarningsSuppressed = new AtomicInteger(0);
private AtomicLong timeStampOfLastReadLockReport = new AtomicLong(0);
private AtomicLong longestReadLockHeldInterval = new AtomicLong(0);
private Timer timer;
/**
* Last time stamp for read lock. Keep the longest one for
* multi-entrance. This is ThreadLocal since there could be
@ -1532,48 +1550,99 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
public void readLock() {
this.fsLock.readLock().lock();
if (this.fsLock.getReadHoldCount() == 1) {
readLockHeldTimeStamp.set(monotonicNow());
readLockHeldTimeStamp.set(timer.monotonicNow());
}
}
@Override
public void readUnlock() {
final boolean needReport = this.fsLock.getReadHoldCount() == 1;
final long readLockInterval = monotonicNow() - readLockHeldTimeStamp.get();
this.fsLock.readLock().unlock();
final long readLockInterval = timer.monotonicNow() -
readLockHeldTimeStamp.get();
if (needReport) {
readLockHeldTimeStamp.remove();
if (readLockInterval > this.readLockReportingThreshold) {
LOG.info("FSNamesystem read lock held for " + readLockInterval +
" ms via\n" + StringUtils.getStackTrace(Thread.currentThread()));
}
}
this.fsLock.readLock().unlock();
if (needReport && readLockInterval >= this.readLockReportingThreshold) {
long localLongestReadLock;
do {
localLongestReadLock = longestReadLockHeldInterval.get();
} while (localLongestReadLock - readLockInterval < 0
&& !longestReadLockHeldInterval.compareAndSet(localLongestReadLock,
readLockInterval));
long localTimeStampOfLastReadLockReport;
long now;
do {
now = timer.monotonicNow();
localTimeStampOfLastReadLockReport = timeStampOfLastReadLockReport
.get();
if (now - localTimeStampOfLastReadLockReport <
lockSuppressWarningInterval) {
numReadLockWarningsSuppressed.incrementAndGet();
return;
}
} while (!timeStampOfLastReadLockReport.compareAndSet(
localTimeStampOfLastReadLockReport, now));
int numSuppressedWarnings = numReadLockWarningsSuppressed.getAndSet(0);
long longestLockHeldInterval = longestReadLockHeldInterval.getAndSet(0);
LOG.info("FSNamesystem read lock held for " + readLockInterval +
" ms via\n" + StringUtils.getStackTrace(Thread.currentThread()) +
"\tNumber of suppressed read-lock reports: " +
numSuppressedWarnings + "\n\tLongest read-lock held interval: " +
longestLockHeldInterval);
}
}
@Override
public void writeLock() {
this.fsLock.writeLock().lock();
if (fsLock.getWriteHoldCount() == 1) {
writeLockHeldTimeStamp = monotonicNow();
writeLockHeldTimeStamp = timer.monotonicNow();
}
}
@Override
public void writeLockInterruptibly() throws InterruptedException {
this.fsLock.writeLock().lockInterruptibly();
if (fsLock.getWriteHoldCount() == 1) {
writeLockHeldTimeStamp = monotonicNow();
writeLockHeldTimeStamp = timer.monotonicNow();
}
}
@Override
public void writeUnlock() {
final boolean needReport = fsLock.getWriteHoldCount() == 1 &&
fsLock.isWriteLockedByCurrentThread();
final long writeLockInterval = monotonicNow() - writeLockHeldTimeStamp;
final long currentTime = timer.monotonicNow();
final long writeLockInterval = currentTime - writeLockHeldTimeStamp;
boolean logReport = false;
int numSuppressedWarnings = 0;
long longestLockHeldInterval = 0;
if (needReport && writeLockInterval >= this.writeLockReportingThreshold) {
if (writeLockInterval > longestWriteLockHeldInterval) {
longestWriteLockHeldInterval = writeLockInterval;
}
if (currentTime - timeStampOfLastWriteLockReport > this
.lockSuppressWarningInterval) {
logReport = true;
numSuppressedWarnings = numWriteLockWarningsSuppressed;
numWriteLockWarningsSuppressed = 0;
longestLockHeldInterval = longestWriteLockHeldInterval;
longestWriteLockHeldInterval = 0;
timeStampOfLastWriteLockReport = currentTime;
} else {
numWriteLockWarningsSuppressed++;
}
}
this.fsLock.writeLock().unlock();
if (needReport && writeLockInterval >= this.writeLockReportingThreshold) {
if (logReport) {
LOG.info("FSNamesystem write lock held for " + writeLockInterval +
" ms via\n" + StringUtils.getStackTrace(Thread.currentThread()));
" ms via\n" + StringUtils.getStackTrace(Thread.currentThread()) +
"\tNumber of suppressed write-lock reports: " +
numSuppressedWarnings + "\n\tLongest write-lock held interval: " +
longestLockHeldInterval);
}
}
@Override
@ -7636,5 +7705,10 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
newSafemode.enter();
this.safeMode = newSafemode;
}
@VisibleForTesting
void setTimer(Timer newTimer) {
this.timer = newTimer;
}
}

85
hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSNamesystem.java
View File

@ -20,6 +20,7 @@ package org.apache.hadoop.hdfs.server.namenode;
import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_EDITS_DIR_KEY;
import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY;
import org.apache.hadoop.util.FakeTimer;
import static org.hamcrest.CoreMatchers.either;
import static org.hamcrest.CoreMatchers.instanceOf;
import static org.junit.Assert.*;
@ -28,7 +29,6 @@ import java.io.File;
import java.io.IOException;
import java.net.InetAddress;
import java.net.URI;
import java.util.ArrayList;
import java.util.Collection;
import com.google.common.base.Supplier;
@ -59,8 +59,8 @@ import java.util.List;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.TimeUnit;
import java.util.concurrent.TimeoutException;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
public class TestFSNamesystem {
@ -296,45 +296,54 @@ public class TestFSNamesystem {
@Test(timeout=45000)
public void testFSWriteLockLongHoldingReport() throws Exception {
final long writeLockReportingThreshold = 100L;
final long writeLockSuppressWarningInterval = 10000L;
Configuration conf = new Configuration();
conf.setLong(DFSConfigKeys.DFS_NAMENODE_WRITE_LOCK_REPORTING_THRESHOLD_MS_KEY,
writeLockReportingThreshold);
conf.setTimeDuration(DFSConfigKeys.DFS_LOCK_SUPPRESS_WARNING_INTERVAL_KEY,
writeLockSuppressWarningInterval, TimeUnit.MILLISECONDS);
FSImage fsImage = Mockito.mock(FSImage.class);
FSEditLog fsEditLog = Mockito.mock(FSEditLog.class);
Mockito.when(fsImage.getEditLog()).thenReturn(fsEditLog);
final FSNamesystem fsn = new FSNamesystem(conf, fsImage);
FakeTimer timer = new FakeTimer();
fsn.setTimer(timer);
timer.advance(writeLockSuppressWarningInterval);
LogCapturer logs = LogCapturer.captureLogs(FSNamesystem.LOG);
GenericTestUtils.setLogLevel(FSNamesystem.LOG, Level.INFO);
// Don't report if the write lock is held for a short time
fsn.writeLock();
Thread.sleep(writeLockReportingThreshold / 2);
fsn.writeUnlock();
assertFalse(logs.getOutput().contains(GenericTestUtils.getMethodName()));
// Report if the write lock is held for a long time
// Report the first write lock warning if it is held for a long time
fsn.writeLock();
Thread.sleep(writeLockReportingThreshold + 10);
timer.advance(writeLockReportingThreshold + 10);
logs.clearOutput();
fsn.writeUnlock();
assertTrue(logs.getOutput().contains(GenericTestUtils.getMethodName()));
// Report if the write lock is held (interruptibly) for a long time
// Track but do not Report if the write lock is held (interruptibly) for
// a long time but time since last report does not exceed the suppress
// warning interval
fsn.writeLockInterruptibly();
Thread.sleep(writeLockReportingThreshold + 10);
timer.advance(writeLockReportingThreshold + 10);
logs.clearOutput();
fsn.writeUnlock();
assertTrue(logs.getOutput().contains(GenericTestUtils.getMethodName()));
assertFalse(logs.getOutput().contains(GenericTestUtils.getMethodName()));
// Report if it's held for a long time when re-entering write lock
// Track but do not Report if it's held for a long time when re-entering
// write lock but time since last report does not exceed the suppress
// warning interval
fsn.writeLock();
Thread.sleep(writeLockReportingThreshold/ 2 + 1);
timer.advance(writeLockReportingThreshold/ 2 + 1);
fsn.writeLockInterruptibly();
Thread.sleep(writeLockReportingThreshold / 2 + 1);
timer.advance(writeLockReportingThreshold/ 2 + 1);
fsn.writeLock();
Thread.sleep(writeLockReportingThreshold / 2);
timer.advance(writeLockReportingThreshold/ 2);
logs.clearOutput();
fsn.writeUnlock();
assertFalse(logs.getOutput().contains(GenericTestUtils.getMethodName()));
@ -343,7 +352,18 @@ public class TestFSNamesystem {
assertFalse(logs.getOutput().contains(GenericTestUtils.getMethodName()));
logs.clearOutput();
fsn.writeUnlock();
assertFalse(logs.getOutput().contains(GenericTestUtils.getMethodName()));
// Report if it's held for a long time and time since last report exceeds
// the supress warning interval
timer.advance(writeLockSuppressWarningInterval);
fsn.writeLock();
timer.advance(writeLockReportingThreshold + 100);
logs.clearOutput();
fsn.writeUnlock();
assertTrue(logs.getOutput().contains(GenericTestUtils.getMethodName()));
assertTrue(logs.getOutput().contains("Number of suppressed write-lock " +
"reports: 2"));
}
/**
@ -353,52 +373,71 @@ public class TestFSNamesystem {
@Test(timeout=45000)
public void testFSReadLockLongHoldingReport() throws Exception {
final long readLockReportingThreshold = 100L;
final long readLockSuppressWarningInterval = 10000L;
final String readLockLogStmt = "FSNamesystem read lock held for ";
Configuration conf = new Configuration();
conf.setLong(
DFSConfigKeys.DFS_NAMENODE_READ_LOCK_REPORTING_THRESHOLD_MS_KEY,
readLockReportingThreshold);
conf.setTimeDuration(DFSConfigKeys.DFS_LOCK_SUPPRESS_WARNING_INTERVAL_KEY,
readLockSuppressWarningInterval, TimeUnit.MILLISECONDS);
FSImage fsImage = Mockito.mock(FSImage.class);
FSEditLog fsEditLog = Mockito.mock(FSEditLog.class);
Mockito.when(fsImage.getEditLog()).thenReturn(fsEditLog);
final FSNamesystem fsn = new FSNamesystem(conf, fsImage);
final FakeTimer timer = new FakeTimer();
fsn.setTimer(timer);
timer.advance(readLockSuppressWarningInterval);
LogCapturer logs = LogCapturer.captureLogs(FSNamesystem.LOG);
GenericTestUtils.setLogLevel(FSNamesystem.LOG, Level.INFO);
// Don't report if the read lock is held for a short time
fsn.readLock();
Thread.sleep(readLockReportingThreshold / 2);
fsn.readUnlock();
assertFalse(logs.getOutput().contains(GenericTestUtils.getMethodName()) &&
logs.getOutput().contains(readLockLogStmt));
// Report if the read lock is held for a long time
// Report the first read lock warning if it is held for a long time
fsn.readLock();
Thread.sleep(readLockReportingThreshold + 10);
timer.advance(readLockReportingThreshold + 10);
logs.clearOutput();
fsn.readUnlock();
assertTrue(logs.getOutput().contains(GenericTestUtils.getMethodName())
&& logs.getOutput().contains(readLockLogStmt));
// Report if it's held for a long time when re-entering read lock
// Track but do not Report if the write lock is held for a long time but
// time since last report does not exceed the suppress warning interval
fsn.readLock();
Thread.sleep(readLockReportingThreshold / 2 + 1);
timer.advance(readLockReportingThreshold + 10);
logs.clearOutput();
fsn.readUnlock();
assertFalse(logs.getOutput().contains(GenericTestUtils.getMethodName())
&& logs.getOutput().contains(readLockLogStmt));
// Track but do not Report if it's held for a long time when re-entering
// read lock but time since last report does not exceed the suppress
// warning interval
fsn.readLock();
Thread.sleep(readLockReportingThreshold / 2 + 1);
timer.advance(readLockReportingThreshold / 2 + 1);
fsn.readLock();
timer.advance(readLockReportingThreshold / 2 + 1);
logs.clearOutput();
fsn.readUnlock();
assertFalse(logs.getOutput().contains(GenericTestUtils.getMethodName()) ||
logs.getOutput().contains(readLockLogStmt));
logs.clearOutput();
fsn.readUnlock();
assertTrue(logs.getOutput().contains(GenericTestUtils.getMethodName()) &&
assertFalse(logs.getOutput().contains(GenericTestUtils.getMethodName()) &&
logs.getOutput().contains(readLockLogStmt));
// Report if it's held for a long time while another thread also has the
// Report if it's held for a long time (and time since last report
// exceeds the suppress warning interval) while another thread also has the
// read lock. Let one thread hold the lock long enough to activate an
// alert, then have another thread grab the read lock to ensure that this
// doesn't reset the timing.
timer.advance(readLockSuppressWarningInterval);
logs.clearOutput();
final CountDownLatch barrier = new CountDownLatch(1);
final CountDownLatch barrier2 = new CountDownLatch(1);
@ -407,7 +446,7 @@ public class TestFSNamesystem {
public void run() {
try {
fsn.readLock();
Thread.sleep(readLockReportingThreshold + 1);
timer.advance(readLockReportingThreshold + 1);
barrier.countDown(); // Allow for t2 to acquire the read lock
barrier2.await(); // Wait until t2 has the read lock
fsn.readUnlock();
@ -442,6 +481,8 @@ public class TestFSNamesystem {
Pattern t2Pattern = Pattern.compile(
String.format(stackTracePatternString, t2.getClass().getName()));
assertFalse(t2Pattern.matcher(logs.getOutput()).find());
assertTrue(logs.getOutput().contains("Number of suppressed read-lock " +
"reports: 2"));
}
@Test