HDFS-15707. NNTop counts don't add up as expected. (#2516)

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Ahmed Hussein 2020-12-07 14:22:06 -06:00 committed by GitHub
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4 changed files with 282 additions and 53 deletions

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@ -23,7 +23,6 @@ import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.hdfs.server.namenode.top.TopConf;
import org.apache.hadoop.hdfs.server.namenode.top.window.RollingWindowManager;
import org.apache.hadoop.hdfs.server.namenode.top.window.RollingWindowManager.Op;
import org.apache.hadoop.hdfs.server.namenode.top.window.RollingWindowManager.User;
@ -144,8 +143,6 @@ public class TopMetrics implements MetricsSource {
for (RollingWindowManager rollingWindowManager : rollingWindowManagers
.values()) {
rollingWindowManager.recordMetric(currTime, cmd, userName, 1);
rollingWindowManager.recordMetric(currTime,
TopConf.ALL_CMDS, userName, 1);
}
}

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@ -113,8 +113,8 @@ public class RollingWindow {
* as well as atomic fields.
*/
private class Bucket {
AtomicLong value = new AtomicLong(0);
AtomicLong updateTime = new AtomicLong(0);
private AtomicLong value = new AtomicLong(0);
private AtomicLong updateTime = new AtomicLong(-1); // -1 = never updated.
/**
* Check whether the last time that the bucket was updated is no longer
@ -125,7 +125,7 @@ public class RollingWindow {
*/
boolean isStaleNow(long time) {
long utime = updateTime.get();
return time - utime >= windowLenMs;
return (utime == -1) || (time - utime >= windowLenMs);
}
/**

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@ -17,20 +17,22 @@
*/
package org.apache.hadoop.hdfs.server.namenode.top.window;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.Stack;
import java.util.concurrent.ConcurrentHashMap;
import org.apache.hadoop.hdfs.server.namenode.top.TopConf;
import org.apache.hadoop.thirdparty.com.google.common.base.Preconditions;
import org.apache.hadoop.thirdparty.com.google.common.collect.Lists;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.hadoop.metrics2.util.Metrics2Util.NameValuePair;
import org.apache.hadoop.metrics2.util.Metrics2Util.TopN;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
@ -66,12 +68,16 @@ public class RollingWindowManager {
public TopWindow(int windowMillis) {
this.windowMillis = windowMillis;
this.top = Lists.newArrayList();
this.top = new LinkedList<>();
}
public void addOp(Op op) {
if (op.getOpType().equals(TopConf.ALL_CMDS)) {
top.add(0, op);
} else {
top.add(op);
}
}
public int getWindowLenMs() {
return windowMillis;
@ -86,41 +92,59 @@ public class RollingWindowManager {
* Represents an operation within a TopWindow. It contains a ranked
* set of the top users for the operation.
*/
public static class Op {
public static class Op implements Comparable<Op> {
private final String opType;
private final List<User> topUsers;
private final List<User> users;
private final long totalCount;
private final int limit;
public Op(String opType, long totalCount) {
public Op(String opType, UserCounts users, int limit) {
this.opType = opType;
this.topUsers = Lists.newArrayList();
this.totalCount = totalCount;
}
public void addUser(User u) {
topUsers.add(u);
this.users = new ArrayList<>(users);
this.users.sort(Collections.reverseOrder());
this.totalCount = users.getTotal();
this.limit = limit;
}
public String getOpType() {
return opType;
}
public List<User> getAllUsers() {
return users;
}
public List<User> getTopUsers() {
return topUsers;
return (users.size() > limit) ? users.subList(0, limit) : users;
}
public long getTotalCount() {
return totalCount;
}
@Override
public int compareTo(Op other) {
return Long.signum(totalCount - other.totalCount);
}
@Override
public boolean equals(Object o) {
return (o instanceof Op) && totalCount == ((Op)o).totalCount;
}
@Override
public int hashCode() {
return opType.hashCode();
}
}
/**
* Represents a user who called an Op within a TopWindow. Specifies the
* user and the number of times the user called the operation.
*/
public static class User {
public static class User implements Comparable<User> {
private final String user;
private final long count;
private long count;
public User(String user, long count) {
this.user = user;
@ -134,6 +158,56 @@ public class RollingWindowManager {
public long getCount() {
return count;
}
public void add(long delta) {
count += delta;
}
@Override
public int compareTo(User other) {
return Long.signum(count - other.count);
}
@Override
public boolean equals(Object o) {
return (o instanceof User) && user.equals(((User)o).user);
}
@Override
public int hashCode() {
return user.hashCode();
}
}
private static class UserCounts extends ArrayList<User> {
private long total = 0;
UserCounts(int capacity) {
super(capacity);
}
@Override
public boolean add(User user) {
long count = user.getCount();
int i = indexOf(user);
if (i == -1) {
super.add(new User(user.getUser(), count));
} else {
get(i).add(count);
}
total += count;
return true;
}
@Override
public boolean addAll(Collection<? extends User> users) {
users.forEach(user -> add(user));
return true;
}
public long getTotal() {
return total;
}
}
/**
@ -142,7 +216,7 @@ public class RollingWindowManager {
* operated on that metric.
*/
public ConcurrentHashMap<String, RollingWindowMap> metricMap =
new ConcurrentHashMap<String, RollingWindowMap>();
new ConcurrentHashMap<>();
public RollingWindowManager(Configuration conf, int reportingPeriodMs) {
@ -191,28 +265,26 @@ public class RollingWindowManager {
Set<String> metricNames = metricMap.keySet();
LOG.debug("iterating in reported metrics, size={} values={}",
metricNames.size(), metricNames);
UserCounts totalCounts = new UserCounts(metricMap.size());
for (Map.Entry<String, RollingWindowMap> entry : metricMap.entrySet()) {
String metricName = entry.getKey();
RollingWindowMap rollingWindows = entry.getValue();
TopN topN = getTopUsersForMetric(time, metricName, rollingWindows);
final int size = topN.size();
if (size == 0) {
continue;
}
Op op = new Op(metricName, topN.getTotal());
window.addOp(op);
// Reverse the users from the TopUsers using a stack,
// since we'd like them sorted in descending rather than ascending order
Stack<NameValuePair> reverse = new Stack<NameValuePair>();
for (int i = 0; i < size; i++) {
reverse.push(topN.poll());
}
for (int i = 0; i < size; i++) {
NameValuePair userEntry = reverse.pop();
User user = new User(userEntry.getName(), userEntry.getValue());
op.addUser(user);
UserCounts topN = getTopUsersForMetric(time, metricName, rollingWindows);
if (!topN.isEmpty()) {
window.addOp(new Op(metricName, topN, topUsersCnt));
totalCounts.addAll(topN);
}
}
// synthesize the overall total op count with the top users for every op.
Set<User> topUsers = new HashSet<>();
for (Op op : window.getOps()) {
topUsers.addAll(op.getTopUsers());
}
// intersect totals with the top users.
totalCounts.retainAll(topUsers);
// allowed to exceed the per-op topUsersCnt to capture total ops for
// any user
window.addOp(new Op(TopConf.ALL_CMDS, totalCounts, Integer.MAX_VALUE));
return window;
}
@ -223,9 +295,9 @@ public class RollingWindowManager {
* @param metricName Name of metric
* @return
*/
private TopN getTopUsersForMetric(long time, String metricName,
private UserCounts getTopUsersForMetric(long time, String metricName,
RollingWindowMap rollingWindows) {
TopN topN = new TopN(topUsersCnt);
UserCounts topN = new UserCounts(topUsersCnt);
Iterator<Map.Entry<String, RollingWindow>> iterator =
rollingWindows.entrySet().iterator();
while (iterator.hasNext()) {
@ -242,7 +314,7 @@ public class RollingWindowManager {
}
LOG.debug("offer window of metric: {} userName: {} sum: {}",
metricName, userName, windowSum);
topN.offer(new NameValuePair(userName, windowSum));
topN.add(new User(userName, windowSum));
}
LOG.debug("topN users size for command {} is: {}",
metricName, topN.size());

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@ -17,12 +17,16 @@
*/
package org.apache.hadoop.hdfs.server.namenode.top.window;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Random;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.hdfs.DFSConfigKeys;
import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.hadoop.hdfs.server.namenode.top.TopConf;
import org.junit.Assert;
import org.junit.Before;
import org.junit.Test;
@ -56,7 +60,7 @@ public class TestRollingWindowManager {
}
@Test
public void testTops() {
public void testTops() throws Exception {
long time = WINDOW_LEN_MS + BUCKET_LEN * 3 / 2;
for (int i = 0; i < users.length; i++)
manager.recordMetric(time, "open", users[i], (i + 1) * 2);
@ -66,11 +70,12 @@ public class TestRollingWindowManager {
time++;
TopWindow tops = manager.snapshot(time);
assertEquals("Unexpected number of ops", 2, tops.getOps().size());
assertEquals("Unexpected number of ops", 3, tops.getOps().size());
assertEquals(TopConf.ALL_CMDS, tops.getOps().get(0).getOpType());
for (Op op : tops.getOps()) {
final List<User> topUsers = op.getTopUsers();
assertEquals("Unexpected number of users", N_TOP_USERS, topUsers.size());
if (op.getOpType() == "open") {
if (op.getOpType().equals("open")) {
for (int i = 0; i < topUsers.size(); i++) {
User user = topUsers.get(i);
assertEquals("Unexpected count for user " + user.getUser(),
@ -86,8 +91,9 @@ public class TestRollingWindowManager {
// move the window forward not to see the "open" results
time += WINDOW_LEN_MS - 2;
tops = manager.snapshot(time);
assertEquals("Unexpected number of ops", 1, tops.getOps().size());
final Op op = tops.getOps().get(0);
assertEquals("Unexpected number of ops", 2, tops.getOps().size());
assertEquals(TopConf.ALL_CMDS, tops.getOps().get(0).getOpType());
final Op op = tops.getOps().get(1);
assertEquals("Should only see close ops", "close", op.getOpType());
final List<User> topUsers = op.getTopUsers();
for (int i = 0; i < topUsers.size(); i++) {
@ -99,4 +105,158 @@ public class TestRollingWindowManager {
assertEquals("Unexpected total count for op",
(1 + users.length) * (users.length / 2), op.getTotalCount());
}
@Test
public void windowReset() throws Exception {
Configuration config = new Configuration();
config.setInt(DFSConfigKeys.NNTOP_BUCKETS_PER_WINDOW_KEY, 1);
config.setInt(DFSConfigKeys.NNTOP_NUM_USERS_KEY, N_TOP_USERS);
int period = 2;
RollingWindowManager rollingWindowManager =
new RollingWindowManager(config, period);
rollingWindowManager.recordMetric(0, "op1", users[0], 3);
checkValues(rollingWindowManager, 0, "op1", 3, 3);
checkValues(rollingWindowManager, period - 1, "op1", 3, 3);
checkValues(rollingWindowManager, period, "op1", 0, 0);
}
@Test
public void testTotal() throws Exception {
Configuration config = new Configuration();
config.setInt(DFSConfigKeys.NNTOP_BUCKETS_PER_WINDOW_KEY, 1);
config.setInt(DFSConfigKeys.NNTOP_NUM_USERS_KEY, N_TOP_USERS);
int period = 10;
RollingWindowManager rollingWindowManager =
new RollingWindowManager(config, period);
long t = 0;
rollingWindowManager.recordMetric(t, "op1", users[0], 3);
checkValues(rollingWindowManager, t, "op1", 3, 3);
// both should have a value.
t = (long)(period * .5);
rollingWindowManager.recordMetric(t, "op2", users[0], 4);
checkValues(rollingWindowManager, t, "op1", 3, 7);
checkValues(rollingWindowManager, t, "op2", 4, 7);
// neither should reset.
t = period - 1;
checkValues(rollingWindowManager, t, "op1", 3, 7);
checkValues(rollingWindowManager, t, "op2", 4, 7);
// op1 should reset in its next period, but not op2.
t = period;
rollingWindowManager.recordMetric(10, "op1", users[0], 10);
checkValues(rollingWindowManager, t, "op1", 10, 14);
checkValues(rollingWindowManager, t, "op2", 4, 14);
// neither should reset.
t = (long)(period * 1.25);
rollingWindowManager.recordMetric(t, "op2", users[0], 7);
checkValues(rollingWindowManager, t, "op1", 10, 21);
checkValues(rollingWindowManager, t, "op2", 11, 21);
// op2 should reset.
t = (long)(period * 1.5);
rollingWindowManager.recordMetric(t, "op2", users[0], 13);
checkValues(rollingWindowManager, t, "op1", 10, 23);
checkValues(rollingWindowManager, t, "op2", 13, 23);
}
@Test
public void testWithFuzzing() throws Exception {
Configuration config = new Configuration();
config.setInt(DFSConfigKeys.NNTOP_BUCKETS_PER_WINDOW_KEY, 1);
config.setInt(DFSConfigKeys.NNTOP_NUM_USERS_KEY, N_TOP_USERS);
int period = users.length/2;
RollingWindowManager rollingWindowManager =
new RollingWindowManager(config, period);
String[] ops = {"op1", "op2", "op3", "op4"};
Random rand = new Random();
for (int i=0; i < 10000; i++) {
rollingWindowManager.recordMetric(i, ops[rand.nextInt(ops.length)],
users[rand.nextInt(users.length)],
rand.nextInt(100));
TopWindow window = rollingWindowManager.snapshot(i);
checkTotal(window);
}
}
@Test
public void testOpTotal() throws Exception {
int numTopUsers = 2;
Configuration config = new Configuration();
config.setInt(DFSConfigKeys.NNTOP_BUCKETS_PER_WINDOW_KEY, 1);
config.setInt(DFSConfigKeys.NNTOP_NUM_USERS_KEY, numTopUsers);
int period = users.length/2;
RollingWindowManager rollingWindowManager =
new RollingWindowManager(config, period);
int numOps = 3;
rollingWindowManager.recordMetric(0, "op1", "user1", 10);
rollingWindowManager.recordMetric(0, "op1", "user2", 20);
rollingWindowManager.recordMetric(0, "op1", "user3", 30);
rollingWindowManager.recordMetric(0, "op2", "user1", 1);
rollingWindowManager.recordMetric(0, "op2", "user4", 40);
rollingWindowManager.recordMetric(0, "op2", "user5", 50);
rollingWindowManager.recordMetric(0, "op3", "user6", 1);
rollingWindowManager.recordMetric(0, "op3", "user7", 11);
rollingWindowManager.recordMetric(0, "op3", "user8", 1);
TopWindow window = rollingWindowManager.snapshot(0);
Assert.assertEquals(numOps + 1, window.getOps().size());
Op allOp = window.getOps().get(0);
Assert.assertEquals(TopConf.ALL_CMDS, allOp.getOpType());
List<User> topUsers = allOp.getTopUsers();
Assert.assertEquals(numTopUsers * numOps, topUsers.size());
// ensure all the top users for each op are present in the total op.
for (int i = 1; i < numOps; i++) {
Assert.assertTrue(
topUsers.containsAll(window.getOps().get(i).getTopUsers()));
}
}
private void checkValues(RollingWindowManager rwManager, long time,
String opType, long value, long expectedTotal) throws Exception {
TopWindow window = rwManager.snapshot(time);
for (Op windowOp : window.getOps()) {
if (opType.equals(windowOp.getOpType())) {
assertEquals(value, windowOp.getTotalCount());
break;
}
}
assertEquals(expectedTotal, checkTotal(window));
}
private long checkTotal(TopWindow window) throws Exception {
long allOpTotal = 0;
long computedOpTotal = 0;
Map<String, User> userOpTally = new HashMap<>();
for (String user : users) {
userOpTally.put(user, new User(user, 0));
}
for (Op windowOp : window.getOps()) {
int multiplier;
if (TopConf.ALL_CMDS.equals(windowOp.getOpType())) {
multiplier = -1;
allOpTotal += windowOp.getTotalCount();
} else {
multiplier = 1;
computedOpTotal += windowOp.getTotalCount();
}
for (User user : windowOp.getAllUsers()) {
userOpTally.get(user.getUser()).add((int)(multiplier*user.getCount()));
}
}
assertEquals(allOpTotal, computedOpTotal);
for (String user : userOpTally.keySet()) {
assertEquals(0, userOpTally.get(user).getCount());
}
return computedOpTotal;
}
}