HDFS-13173. Replace ArrayList with DirectoryDiffList(SnapshotSkipList) to store DirectoryDiffs. Contributed by Shashikant Banerjee

This commit is contained in:
Tsz-Wo Nicholas Sze 2018-03-02 17:46:50 -08:00
parent 90d2bdcb75
commit ba82e5c488
8 changed files with 109 additions and 19 deletions

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@ -419,6 +419,15 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
"dfs.namenode.snapshot.max.limit";
public static final int DFS_NAMENODE_SNAPSHOT_MAX_LIMIT_DEFAULT = 65536;
public static final String DFS_NAMENODE_SNAPSHOT_SKIPLIST_SKIP_INTERVAL =
"dfs.namenode.snapshot.skiplist.interval";
public static final int DFS_NAMENODE_SNAPSHOT_SKIPLIST_SKIP_INTERVAL_DEFAULT =
10;
public static final String DFS_NAMENODE_SNAPSHOT_SKIPLIST_MAX_LEVELS =
"dfs.namenode.snapshot.skiplist.max.levels";
public static final int
DFS_NAMENODE_SNAPSHOT_SKIPLIST_MAX_SKIP_LEVELS_DEFAULT = 0;
// Whether to enable datanode's stale state detection and usage for reads
public static final String DFS_NAMENODE_AVOID_STALE_DATANODE_FOR_READ_KEY = "dfs.namenode.avoid.read.stale.datanode";
public static final boolean DFS_NAMENODE_AVOID_STALE_DATANODE_FOR_READ_DEFAULT = false;

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@ -138,10 +138,14 @@ abstract class AbstractINodeDiffList<N extends INode,
return n == 0 ? null : diffs.get(n - 1);
}
DiffList<D> newDiffs() {
return new DiffListByArrayList<>(
INodeDirectory.DEFAULT_FILES_PER_DIRECTORY);
}
private void createDiffsIfNeeded() {
if (diffs == null) {
diffs =
new DiffListByArrayList<>(INodeDirectory.DEFAULT_FILES_PER_DIRECTORY);
diffs = newDiffs();
}
}

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@ -68,9 +68,9 @@ import java.util.concurrent.ThreadLocalRandom;
* <p>
* Once a snapshot gets deleted, the list needs to be balanced.
*/
public class DirectoryDiffList implements DiffList<DirectoryDiff> {
public class DiffListBySkipList implements DiffList<DirectoryDiff> {
public static final Logger LOG =
LoggerFactory.getLogger(DirectoryDiffList.class);
LoggerFactory.getLogger(DiffListBySkipList.class);
private static class SkipDiff {
/**
@ -240,7 +240,7 @@ public class DirectoryDiffList implements DiffList<DirectoryDiff> {
/**
* Constructs a new, empty instance of SkipList.
*/
public DirectoryDiffList(int capacity, int interval, int skipLevel) {
public DiffListBySkipList(int capacity, int interval, int skipLevel) {
skipNodeList = new ArrayList<>(capacity);
head = new SkipListNode(null, 0);
this.maxSkipLevels = skipLevel;

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@ -0,0 +1,46 @@
/**
* 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.hdfs.server.namenode.snapshot;
import org.apache.commons.logging.Log;
import org.apache.hadoop.hdfs.server.namenode.snapshot.DirectoryWithSnapshotFeature.DirectoryDiff;
import java.util.function.IntFunction;
/** For creating {@link DiffList} for {@link DirectoryDiff}. */
public abstract class DirectoryDiffListFactory {
public static DiffList<DirectoryDiff> createDiffList(int capacity) {
return constructor.apply(capacity);
}
public static void init(int skipInterval, int maxLevels, Log log) {
if (maxLevels > 0) {
constructor = c -> new DiffListBySkipList(c, skipInterval, maxLevels);
log.info("SkipList is enabled with skipInterval=" + skipInterval
+ ", maxLevels=" + maxLevels);
} else {
constructor = c -> new DiffListByArrayList<>(c);
log.info("SkipList is disabled");
}
}
private static volatile IntFunction<DiffList<DirectoryDiff>> constructor
= c -> new DiffListByArrayList<>(c);
private DirectoryDiffListFactory() {}
}

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@ -334,6 +334,12 @@ public class DirectoryWithSnapshotFeature implements INode.Feature {
: new INodeDirectoryAttributes.SnapshotCopy(currentDir);
}
@Override
DiffList<DirectoryDiff> newDiffs() {
return DirectoryDiffListFactory
.createDiffList(INodeDirectory.DEFAULT_FILES_PER_DIRECTORY);
}
/** Replace the given child in the created/deleted list, if there is any. */
public boolean replaceChild(final ListType type, final INode oldChild,
final INode newChild) {

View File

@ -127,6 +127,14 @@ public class SnapshotManager implements SnapshotStatsMXBean {
+ snapshotDiffAllowSnapRootDescendant
+ ", maxSnapshotLimit: "
+ maxSnapshotLimit);
final int maxLevels = conf.getInt(
DFSConfigKeys.DFS_NAMENODE_SNAPSHOT_SKIPLIST_MAX_LEVELS,
DFSConfigKeys.DFS_NAMENODE_SNAPSHOT_SKIPLIST_MAX_SKIP_LEVELS_DEFAULT);
final int skipInterval = conf.getInt(
DFSConfigKeys.DFS_NAMENODE_SNAPSHOT_SKIPLIST_SKIP_INTERVAL,
DFSConfigKeys.DFS_NAMENODE_SNAPSHOT_SKIPLIST_SKIP_INTERVAL_DEFAULT);
DirectoryDiffListFactory.init(skipInterval, maxLevels, LOG);
}
@VisibleForTesting

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@ -4362,7 +4362,6 @@
across to the client within one rpc call.
</description>
</property>
<property>
<name>dfs.namenode.snapshot.max.limit</name>
<value>65536</value>
@ -4373,6 +4372,24 @@
</description>
</property>
<property>
<name>dfs.namenode.snapshot.skiplist.max.levels</name>
<value>0</value>
<description>
Maximum no of the skip levels to be maintained in the skip list for
storing directory snapshot diffs. By default, it is set to 0 and a linear
list will be used to store the directory snapshot diffs.
</description>
</property>
<property>
<name>dfs.namenode.snapshot.skiplist.interval</name>
<value>10</value>
<description>
The interval after which the skip levels will be formed in the skip list
for storing directory snapshot diffs. By default, value is set to 10.
</description>
</property>
<property>
<name>dfs.pipeline.ecn</name>
<value>false</value>

View File

@ -41,7 +41,7 @@ import java.util.function.IntFunction;
/**
* This class tests the DirectoryDiffList API's.
*/
public class TestDirectoryDiffList{
public class TestDiffListBySkipList {
static final int NUM_SNAPSHOTS = 100;
static {
SnapshotTestHelper.disableLogs();
@ -78,7 +78,7 @@ public class TestDirectoryDiffList{
}
}
static void verifyChildrenList(DirectoryDiffList skip, INodeDirectory dir) {
static void verifyChildrenList(DiffListBySkipList skip, INodeDirectory dir) {
final int n = skip.size();
for (int i = 0; i < skip.size(); i++) {
final List<INode> expected = ReadOnlyList.Util.asList(
@ -95,7 +95,7 @@ public class TestDirectoryDiffList{
}
static void verifyChildrenList(
DiffList<DirectoryDiff> array, DirectoryDiffList skip,
DiffList<DirectoryDiff> array, DiffListBySkipList skip,
INodeDirectory dir, List<INode> childrenList) {
final int n = array.size();
Assert.assertEquals(n, skip.size());
@ -144,13 +144,13 @@ public class TestDirectoryDiffList{
static void testAddLast(int n) throws Exception {
final Path root = new Path("/testAddLast" + n);
DirectoryDiffList.LOG.info("run " + root);
DiffListBySkipList.LOG.info("run " + root);
final DirectoryDiffList skipList = new DirectoryDiffList(0, 3, 5);
final DiffListBySkipList skipList = new DiffListBySkipList(0, 3, 5);
final DiffList<DirectoryDiff> arrayList = new DiffListByArrayList<>(0);
INodeDirectory dir = addDiff(n, skipList, arrayList, root);
// verify that the both the children list obtained from hdfs and
// DirectoryDiffList are same
// DiffListBySkipList are same
verifyChildrenList(skipList, dir);
verifyChildrenList(arrayList, skipList, dir, Collections.emptyList());
}
@ -163,7 +163,7 @@ public class TestDirectoryDiffList{
static void testAddFirst(int n) throws Exception {
final Path root = new Path("/testAddFirst" + n);
DirectoryDiffList.LOG.info("run " + root);
DiffListBySkipList.LOG.info("run " + root);
hdfs.mkdirs(root);
for (int i = 1; i < n; i++) {
@ -180,7 +180,7 @@ public class TestDirectoryDiffList{
DiffList<DirectoryDiff> diffs = dir.getDiffs().asList();
List<INode> childrenList = ReadOnlyList.Util.asList(dir.getChildrenList(
diffs.get(0).getSnapshotId()));
final DirectoryDiffList skipList = new DirectoryDiffList(0, 3, 5);
final DiffListBySkipList skipList = new DiffListBySkipList(0, 3, 5);
final DiffList<DirectoryDiff> arrayList = new DiffListByArrayList<>(0);
for (int i = diffs.size() - 1; i >= 0; i--) {
final DirectoryDiff d = diffs.get(i);
@ -188,7 +188,7 @@ public class TestDirectoryDiffList{
arrayList.addFirst(d);
}
// verify that the both the children list obtained from hdfs and
// DirectoryDiffList are same
// DiffListBySkipList are same
verifyChildrenList(skipList, dir);
verifyChildrenList(arrayList, skipList, dir, childrenList);
}
@ -231,9 +231,9 @@ public class TestDirectoryDiffList{
static void testRemove(String name, int n, IntFunction<Integer> indexFunction)
throws Exception {
final Path root = new Path("/testRemove" + name + n);
DirectoryDiffList.LOG.info("run " + root);
DiffListBySkipList.LOG.info("run " + root);
final DirectoryDiffList skipList = new DirectoryDiffList(0, 3, 5);
final DiffListBySkipList skipList = new DiffListBySkipList(0, 3, 5);
final DiffList<DirectoryDiff> arrayList = new DiffListByArrayList<>(0);
final INodeDirectory dir = addDiff(n, skipList, arrayList, root);
Assert.assertEquals(n, arrayList.size());
@ -248,9 +248,9 @@ public class TestDirectoryDiffList{
}
}
static DirectoryDiff remove(int i, DirectoryDiffList skip,
static DirectoryDiff remove(int i, DiffListBySkipList skip,
DiffList<DirectoryDiff> array) {
DirectoryDiffList.LOG.info("remove " + i);
DiffListBySkipList.LOG.info("remove " + i);
final DirectoryDiff expected = array.remove(i);
final DirectoryDiff computed = skip.remove(i);
assertDirectoryDiff(expected, computed);