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HADOOP-13649 s3guard: implement time-based (TTL) expiry for LocalMetadataStore (Gabor Bota)

This commit is contained in:
Aaron Fabbri 2018-05-08 15:29:46 -07:00
parent 1ef0a1db1d
commit 69aac696d9
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GPG Key ID: B2EEFA9E78118A29
3 changed files with 153 additions and 111 deletions
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93
hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/s3guard/LocalMetadataStore.java
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@ -21,7 +21,10 @@ package org.apache.hadoop.fs.s3a.s3guard;
import com.google.common.annotations.VisibleForTesting;
import com.google.common.base.Preconditions;
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import org.apache.commons.lang.StringUtils;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.FileStatus;
import org.apache.hadoop.fs.FileSystem;
@ -37,6 +40,7 @@ import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedList;
import java.util.Map;
import java.util.concurrent.TimeUnit;
/**
* This is a local, in-memory, implementation of MetadataStore.
@ -51,24 +55,35 @@ import java.util.Map;
* This MetadataStore does not enforce filesystem rules such as disallowing
* non-recursive removal of non-empty directories. It is assumed the caller
* already has to perform these sorts of checks.
*
* Contains cache internally with time based eviction.
*/
public class LocalMetadataStore implements MetadataStore {
public static final Logger LOG = LoggerFactory.getLogger(MetadataStore.class);
// TODO HADOOP-13649: use time instead of capacity for eviction.
public static final int DEFAULT_MAX_RECORDS = 128;
public static final int DEFAULT_CACHE_ENTRY_TTL_MSEC = 10 * 1000;
/**
* Maximum number of records.
*/
@InterfaceStability.Evolving
public static final String CONF_MAX_RECORDS =
"fs.metadatastore.local.max_records";
/**
* Time to live in milliseconds. If zero, time-based expiration is
* disabled.
*/
@InterfaceStability.Evolving
public static final String CONF_CACHE_ENTRY_TTL =
"fs.metadatastore.local.ttl";
/** Contains directories and files. */
private LruHashMap<Path, PathMetadata> fileHash;
private Cache<Path, PathMetadata> fileCache;
/** Contains directory listings. */
private LruHashMap<Path, DirListingMetadata> dirHash;
private Cache<Path, DirListingMetadata> dirCache;
private FileSystem fs;
/* Null iff this FS does not have an associated URI host. */
@ -94,9 +109,15 @@ public class LocalMetadataStore implements MetadataStore {
if (maxRecords < 4) {
maxRecords = 4;
}
// Start w/ less than max capacity. Space / time trade off.
fileHash = new LruHashMap<>(maxRecords/2, maxRecords);
dirHash = new LruHashMap<>(maxRecords/4, maxRecords);
int ttl = conf.getInt(CONF_CACHE_ENTRY_TTL, DEFAULT_CACHE_ENTRY_TTL_MSEC);
CacheBuilder builder = CacheBuilder.newBuilder().maximumSize(maxRecords);
if (ttl >= 0) {
builder.expireAfterAccess(ttl, TimeUnit.MILLISECONDS);
}
fileCache = builder.build();
dirCache = builder.build();
}
@Override
@ -130,12 +151,12 @@ public class LocalMetadataStore implements MetadataStore {
// Delete entry from file cache, then from cached parent directory, if any
deleteHashEntries(path, tombstone);
deleteCacheEntries(path, tombstone);
if (recursive) {
// Remove all entries that have this dir as path prefix.
deleteHashByAncestor(path, dirHash, tombstone);
deleteHashByAncestor(path, fileHash, tombstone);
deleteEntryByAncestor(path, dirCache, tombstone);
deleteEntryByAncestor(path, fileCache, tombstone);
}
}
@ -149,7 +170,7 @@ public class LocalMetadataStore implements MetadataStore {
throws IOException {
Path path = standardize(p);
synchronized (this) {
PathMetadata m = fileHash.mruGet(path);
PathMetadata m = fileCache.getIfPresent(path);
if (wantEmptyDirectoryFlag && m != null &&
m.getFileStatus().isDirectory()) {
@ -170,7 +191,7 @@ public class LocalMetadataStore implements MetadataStore {
* @return TRUE / FALSE if known empty / not-empty, UNKNOWN otherwise.
*/
private Tristate isEmptyDirectory(Path p) {
DirListingMetadata dirMeta = dirHash.get(p);
DirListingMetadata dirMeta = dirCache.getIfPresent(p);
return dirMeta.withoutTombstones().isEmpty();
}
@ -178,7 +199,7 @@ public class LocalMetadataStore implements MetadataStore {
public synchronized DirListingMetadata listChildren(Path p) throws
IOException {
Path path = standardize(p);
DirListingMetadata listing = dirHash.mruGet(path);
DirListingMetadata listing = dirCache.getIfPresent(path);
if (LOG.isDebugEnabled()) {
LOG.debug("listChildren({}) -> {}", path,
listing == null ? "null" : listing.prettyPrint());
@ -237,10 +258,10 @@ public class LocalMetadataStore implements MetadataStore {
if (LOG.isDebugEnabled()) {
LOG.debug("put {} -> {}", path, meta.prettyPrint());
}
fileHash.put(path, meta);
fileCache.put(path, meta);
/* Directory case:
* We also make sure we have an entry in the dirHash, so subsequent
* We also make sure we have an entry in the dirCache, so subsequent
* listStatus(path) at least see the directory.
*
* If we had a boolean flag argument "isNew", we would know whether this
@ -251,9 +272,9 @@ public class LocalMetadataStore implements MetadataStore {
*/
if (status.isDirectory()) {
DirListingMetadata dir = dirHash.mruGet(path);
DirListingMetadata dir = dirCache.getIfPresent(path);
if (dir == null) {
dirHash.put(path, new DirListingMetadata(path, DirListingMetadata
dirCache.put(path, new DirListingMetadata(path, DirListingMetadata
.EMPTY_DIR, false));
}
}
@ -261,14 +282,14 @@ public class LocalMetadataStore implements MetadataStore {
/* Update cached parent dir. */
Path parentPath = path.getParent();
if (parentPath != null) {
DirListingMetadata parent = dirHash.mruGet(parentPath);
DirListingMetadata parent = dirCache.getIfPresent(parentPath);
if (parent == null) {
/* Track this new file's listing in parent. Parent is not
* authoritative, since there may be other items in it we don't know
* about. */
parent = new DirListingMetadata(parentPath,
DirListingMetadata.EMPTY_DIR, false);
dirHash.put(parentPath, parent);
dirCache.put(parentPath, parent);
}
parent.put(status);
}
@ -280,7 +301,7 @@ public class LocalMetadataStore implements MetadataStore {
if (LOG.isDebugEnabled()) {
LOG.debug("put dirMeta {}", meta.prettyPrint());
}
dirHash.put(standardize(meta.getPath()), meta);
dirCache.put(standardize(meta.getPath()), meta);
put(meta.getListing());
}
@ -298,8 +319,8 @@ public class LocalMetadataStore implements MetadataStore {
@Override
public void destroy() throws IOException {
if (dirHash != null) {
dirHash.clear();
if (dirCache != null) {
dirCache.invalidateAll();
}
}
@ -312,7 +333,7 @@ public class LocalMetadataStore implements MetadataStore {
public synchronized void prune(long modTime, String keyPrefix)
throws IOException {
Iterator<Map.Entry<Path, PathMetadata>> files =
fileHash.entrySet().iterator();
fileCache.asMap().entrySet().iterator();
while (files.hasNext()) {
Map.Entry<Path, PathMetadata> entry = files.next();
if (expired(entry.getValue().getFileStatus(), modTime, keyPrefix)) {
@ -320,7 +341,7 @@ public class LocalMetadataStore implements MetadataStore {
}
}
Iterator<Map.Entry<Path, DirListingMetadata>> dirs =
dirHash.entrySet().iterator();
dirCache.asMap().entrySet().iterator();
while (dirs.hasNext()) {
Map.Entry<Path, DirListingMetadata> entry = dirs.next();
Path path = entry.getKey();
@ -335,9 +356,10 @@ public class LocalMetadataStore implements MetadataStore {
}
}
if (newChildren.size() != oldChildren.size()) {
dirHash.put(path, new DirListingMetadata(path, newChildren, false));
dirCache.put(path, new DirListingMetadata(path, newChildren, false));
if (!path.isRoot()) {
DirListingMetadata parent = dirHash.get(path.getParent());
DirListingMetadata parent = null;
parent = dirCache.getIfPresent(path.getParent());
if (parent != null) {
parent.setAuthoritative(false);
}
@ -354,9 +376,9 @@ public class LocalMetadataStore implements MetadataStore {
}
@VisibleForTesting
static <T> void deleteHashByAncestor(Path ancestor, Map<Path, T> hash,
static <T> void deleteEntryByAncestor(Path ancestor, Cache<Path, T> cache,
boolean tombstone) {
for (Iterator<Map.Entry<Path, T>> it = hash.entrySet().iterator();
for (Iterator<Map.Entry<Path, T>> it = cache.asMap().entrySet().iterator();
it.hasNext();) {
Map.Entry<Path, T> entry = it.next();
Path f = entry.getKey();
@ -364,11 +386,11 @@ public class LocalMetadataStore implements MetadataStore {
if (isAncestorOf(ancestor, f)) {
if (tombstone) {
if (meta instanceof PathMetadata) {
entry.setValue((T) PathMetadata.tombstone(f));
cache.put(f, (T) PathMetadata.tombstone(f));
} else if (meta instanceof DirListingMetadata) {
it.remove();
} else {
throw new IllegalStateException("Unknown type in hash");
throw new IllegalStateException("Unknown type in cache");
}
} else {
it.remove();
@ -391,17 +413,17 @@ public class LocalMetadataStore implements MetadataStore {
}
/**
* Update fileHash and dirHash to reflect deletion of file 'f'. Call with
* Update fileCache and dirCache to reflect deletion of file 'f'. Call with
* lock held.
*/
private void deleteHashEntries(Path path, boolean tombstone) {
private void deleteCacheEntries(Path path, boolean tombstone) {
// Remove target file/dir
LOG.debug("delete file entry for {}", path);
if (tombstone) {
fileHash.put(path, PathMetadata.tombstone(path));
fileCache.put(path, PathMetadata.tombstone(path));
} else {
fileHash.remove(path);
fileCache.invalidate(path);
}
// Update this and parent dir listing, if any
@ -409,12 +431,13 @@ public class LocalMetadataStore implements MetadataStore {
/* If this path is a dir, remove its listing */
LOG.debug("removing listing of {}", path);
dirHash.remove(path);
dirCache.invalidate(path);
/* Remove this path from parent's dir listing */
Path parent = path.getParent();
if (parent != null) {
DirListingMetadata dir = dirHash.get(parent);
DirListingMetadata dir = null;
dir = dirCache.getIfPresent(parent);
if (dir != null) {
LOG.debug("removing parent's entry for {} ", path);
if (tombstone) {

50
hadoop-tools/hadoop-aws/src/main/java/org/apache/hadoop/fs/s3a/s3guard/LruHashMap.java
View File

@ -1,50 +0,0 @@
/*
* 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.fs.s3a.s3guard;
import java.util.LinkedHashMap;
import java.util.Map;
/**
* LinkedHashMap that implements a maximum size and LRU eviction policy.
*/
public class LruHashMap<K, V> extends LinkedHashMap<K, V> {
private final int maxSize;
public LruHashMap(int initialCapacity, int maxSize) {
super(initialCapacity);
this.maxSize = maxSize;
}
@Override
protected boolean removeEldestEntry(Map.Entry<K, V> eldest) {
return size() > maxSize;
}
/**
* get() plus side-effect of making the element Most Recently Used.
* @param key lookup key
* @return value
*/
public V mruGet(K key) {
V val = remove(key);
if (val != null) {
put(key, val);
}
return val;
}
}

121
hadoop-tools/hadoop-aws/src/test/java/org/apache/hadoop/fs/s3a/s3guard/TestLocalMetadataStore.java
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@ -19,9 +19,11 @@
package org.apache.hadoop.fs.s3a.s3guard;
import java.io.IOException;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.TimeUnit;
import com.google.common.base.Ticker;
import com.google.common.cache.Cache;
import com.google.common.cache.CacheBuilder;
import org.junit.Test;
import org.apache.hadoop.conf.Configuration;
@ -75,38 +77,105 @@ public class TestLocalMetadataStore extends MetadataStoreTestBase {
@Test
public void testClearByAncestor() {
Map<Path, PathMetadata> map = new HashMap<>();
Cache<Path, PathMetadata> cache = CacheBuilder.newBuilder().build();
// 1. Test paths without scheme/host
assertClearResult(map, "", "/", 0);
assertClearResult(map, "", "/dirA/dirB", 2);
assertClearResult(map, "", "/invalid", 5);
assertClearResult(cache, "", "/", 0);
assertClearResult(cache, "", "/dirA/dirB", 2);
assertClearResult(cache, "", "/invalid", 5);
// 2. Test paths w/ scheme/host
String p = "s3a://fake-bucket-name";
assertClearResult(map, p, "/", 0);
assertClearResult(map, p, "/dirA/dirB", 2);
assertClearResult(map, p, "/invalid", 5);
assertClearResult(cache, p, "/", 0);
assertClearResult(cache, p, "/dirA/dirB", 2);
assertClearResult(cache, p, "/invalid", 5);
}
private static void populateMap(Map<Path, PathMetadata> map,
static class TestTicker extends Ticker {
private long myTicker = 0;
@Override public long read() {
return myTicker;
}
public void set(long val) {
this.myTicker = val;
}
}
/**
* Test that time eviction in cache used in {@link LocalMetadataStore}
* implementation working properly.
*
* The test creates a Ticker instance, which will be used to control the
* internal clock of the cache to achieve eviction without having to wait
* for the system clock.
* The test creates 3 entry: 2nd and 3rd entry will survive the eviction,
* because it will be created later than the 1st - using the ticker.
*/
@Test
public void testCacheTimedEvictionAfterWrite() {
TestTicker testTicker = new TestTicker();
final long t0 = testTicker.read();
final long t1 = t0 + 100;
final long t2 = t1 + 100;
final long ttl = t1 + 50; // between t1 and t2
Cache<Path, PathMetadata> cache = CacheBuilder.newBuilder()
.expireAfterWrite(ttl,
TimeUnit.NANOSECONDS /* nanos to avoid conversions */)
.ticker(testTicker)
.build();
String p = "s3a://fake-bucket-name";
Path path1 = new Path(p + "/dirA/dirB/file1");
Path path2 = new Path(p + "/dirA/dirB/file2");
Path path3 = new Path(p + "/dirA/dirB/file3");
// Test time is t0
populateEntry(cache, path1);
// set new value on the ticker, so the next two entries will be added later
testTicker.set(t1); // Test time is now t1
populateEntry(cache, path2);
populateEntry(cache, path3);
assertEquals("Cache should contain 3 records before eviction",
3, cache.size());
PathMetadata pm1 = cache.getIfPresent(path1);
assertNotNull("PathMetadata should not be null before eviction", pm1);
// set the ticker to a time when timed eviction should occur
// for the first entry
testTicker.set(t2);
// call cleanup explicitly, as timed expiration is performed with
// periodic maintenance during writes and occasionally during reads only
cache.cleanUp();
assertEquals("Cache size should be 2 after eviction", 2, cache.size());
pm1 = cache.getIfPresent(path1);
assertNull("PathMetadata should be null after eviction", pm1);
}
private static void populateMap(Cache<Path, PathMetadata> cache,
String prefix) {
populateEntry(map, new Path(prefix + "/dirA/dirB/"));
populateEntry(map, new Path(prefix + "/dirA/dirB/dirC"));
populateEntry(map, new Path(prefix + "/dirA/dirB/dirC/file1"));
populateEntry(map, new Path(prefix + "/dirA/dirB/dirC/file2"));
populateEntry(map, new Path(prefix + "/dirA/file1"));
populateEntry(cache, new Path(prefix + "/dirA/dirB/"));
populateEntry(cache, new Path(prefix + "/dirA/dirB/dirC"));
populateEntry(cache, new Path(prefix + "/dirA/dirB/dirC/file1"));
populateEntry(cache, new Path(prefix + "/dirA/dirB/dirC/file2"));
populateEntry(cache, new Path(prefix + "/dirA/file1"));
}
private static void populateEntry(Map<Path, PathMetadata> map,
private static void populateEntry(Cache<Path, PathMetadata> cache,
Path path) {
map.put(path, new PathMetadata(new FileStatus(0, true, 0, 0, 0, path)));
cache.put(path, new PathMetadata(new FileStatus(0, true, 0, 0, 0, path)));
}
private static int sizeOfMap(Map<Path, PathMetadata> map) {
private static int sizeOfMap(Cache<Path, PathMetadata> cache) {
int count = 0;
for (PathMetadata meta : map.values()) {
for (PathMetadata meta : cache.asMap().values()) {
if (!meta.isDeleted()) {
count++;
}
@ -114,14 +183,14 @@ public class TestLocalMetadataStore extends MetadataStoreTestBase {
return count;
}
private static void assertClearResult(Map <Path, PathMetadata> map,
private static void assertClearResult(Cache<Path, PathMetadata> cache,
String prefixStr, String pathStr, int leftoverSize) {
populateMap(map, prefixStr);
LocalMetadataStore.deleteHashByAncestor(new Path(prefixStr + pathStr), map,
true);
assertEquals(String.format("Map should have %d entries", leftoverSize),
leftoverSize, sizeOfMap(map));
map.clear();
populateMap(cache, prefixStr);
LocalMetadataStore.deleteEntryByAncestor(new Path(prefixStr + pathStr),
cache, true);
assertEquals(String.format("Cache should have %d entries", leftoverSize),
leftoverSize, sizeOfMap(cache));
cache.invalidateAll();
}
@Override