CRUNCH-596 Support right-outer bloom join
Signed-off-by: Gabriel Reid <greid@apache.org>
diff --git a/crunch-core/src/it/java/org/apache/crunch/lib/join/BloomFilterFullOuterJoinIT.java b/crunch-core/src/it/java/org/apache/crunch/lib/join/BloomFilterFullOuterJoinIT.java
new file mode 100644
index 0000000..18a0100
--- /dev/null
+++ b/crunch-core/src/it/java/org/apache/crunch/lib/join/BloomFilterFullOuterJoinIT.java
@@ -0,0 +1,49 @@
+/**
+ * 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.crunch.lib.join;
+
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+
+public class BloomFilterFullOuterJoinIT extends AbstractFullOuterJoinIT {
+
+ private static String saveTempDir;
+
+ @BeforeClass
+ public static void setUpClass(){
+
+ // Ensure a consistent temporary directory for use of the DistributedCache.
+
+ // The DistributedCache technically isn't supported when running in local mode, and the default
+ // temporary directiory "/tmp" is used as its location. This typically only causes an issue when
+ // running integration tests on Mac OS X, as OS X doesn't use "/tmp" as it's default temporary
+ // directory. The following call ensures that "/tmp" is used as the temporary directory on all platforms.
+ saveTempDir = System.setProperty("java.io.tmpdir", "/tmp");
+ }
+
+ @AfterClass
+ public static void tearDownClass(){
+ System.setProperty("java.io.tmpdir", saveTempDir);
+ }
+
+ @Override
+ protected <K, U, V> JoinStrategy<K, U, V> getJoinStrategy() {
+ return new BloomFilterJoinStrategy<K, U, V>(20000);
+ }
+
+}
diff --git a/crunch-core/src/it/java/org/apache/crunch/lib/join/BloomFilterRightOuterJoinIT.java b/crunch-core/src/it/java/org/apache/crunch/lib/join/BloomFilterRightOuterJoinIT.java
new file mode 100644
index 0000000..750bd35
--- /dev/null
+++ b/crunch-core/src/it/java/org/apache/crunch/lib/join/BloomFilterRightOuterJoinIT.java
@@ -0,0 +1,49 @@
+/**
+ * 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.crunch.lib.join;
+
+import org.junit.AfterClass;
+import org.junit.BeforeClass;
+
+public class BloomFilterRightOuterJoinIT extends AbstractRightOuterJoinIT {
+
+ private static String saveTempDir;
+
+ @BeforeClass
+ public static void setUpClass(){
+
+ // Ensure a consistent temporary directory for use of the DistributedCache.
+
+ // The DistributedCache technically isn't supported when running in local mode, and the default
+ // temporary directiory "/tmp" is used as its location. This typically only causes an issue when
+ // running integration tests on Mac OS X, as OS X doesn't use "/tmp" as it's default temporary
+ // directory. The following call ensures that "/tmp" is used as the temporary directory on all platforms.
+ saveTempDir = System.setProperty("java.io.tmpdir", "/tmp");
+ }
+
+ @AfterClass
+ public static void tearDownClass(){
+ System.setProperty("java.io.tmpdir", saveTempDir);
+ }
+
+ @Override
+ protected <K, U, V> JoinStrategy<K, U, V> getJoinStrategy() {
+ return new BloomFilterJoinStrategy<K, U, V>(20000);
+ }
+
+}
diff --git a/crunch-core/src/main/java/org/apache/crunch/fn/ExtractKeyFn.java b/crunch-core/src/main/java/org/apache/crunch/fn/ExtractKeyFn.java
index 2d2776e..e88a5b1 100644
--- a/crunch-core/src/main/java/org/apache/crunch/fn/ExtractKeyFn.java
+++ b/crunch-core/src/main/java/org/apache/crunch/fn/ExtractKeyFn.java
@@ -23,8 +23,9 @@
import org.apache.hadoop.mapreduce.TaskInputOutputContext;
/**
- * Wrapper function for converting a {@code MapFn} into a key-value pair that is
- * used to convert from a {@code PCollection<V>} to a {@code PTable<K, V>}.
+ * Wrapper function for converting a key-from-value extractor {@code MapFn<V, K>} into a
+ * key-value pair extractor that is used to convert from a {@code PCollection<V>} to a
+ * {@code PTable<K, V>}.
*/
public class ExtractKeyFn<K, V> extends MapFn<V, Pair<K, V>> {
diff --git a/crunch-core/src/main/java/org/apache/crunch/lib/join/BloomFilterJoinStrategy.java b/crunch-core/src/main/java/org/apache/crunch/lib/join/BloomFilterJoinStrategy.java
index 8fda17c..7ff7490 100644
--- a/crunch-core/src/main/java/org/apache/crunch/lib/join/BloomFilterJoinStrategy.java
+++ b/crunch-core/src/main/java/org/apache/crunch/lib/join/BloomFilterJoinStrategy.java
@@ -33,6 +33,9 @@
import org.apache.crunch.Pair;
import org.apache.crunch.ParallelDoOptions;
import org.apache.crunch.ReadableData;
+import org.apache.crunch.fn.ExtractKeyFn;
+import org.apache.crunch.fn.FilterFns;
+import org.apache.crunch.fn.IdentityFn;
import org.apache.crunch.types.PType;
import org.apache.crunch.types.PTypeFamily;
import org.apache.crunch.types.avro.AvroMode;
@@ -57,6 +60,10 @@
* This strategy is useful in cases where the right-side table contains many keys that are not
* present in the left-side table. In this case, the use of the Bloom filter avoids a
* potentially costly shuffle phase for data that would never be joined to the left side.
+ * <p>
+ * Implementation Note: right and full outer join type are handled by splitting the right-side
+ * table (the bigger one) into two disjunctive streams: negatively filtered (right outer part)
+ * and positively filtered (passed to delegate strategy).
*/
public class BloomFilterJoinStrategy<K, U, V> implements JoinStrategy<K, U, V> {
@@ -120,30 +127,42 @@
@Override
public PTable<K, Pair<U, V>> join(PTable<K, U> left, PTable<K, V> right, JoinType joinType) {
- if (joinType != JoinType.INNER_JOIN && joinType != JoinType.LEFT_OUTER_JOIN) {
- throw new IllegalStateException("JoinType " + joinType + " is not supported for BloomFilter joins");
- }
-
- PTable<K,V> filteredRightSide;
PType<BloomFilter> bloomFilterType = getBloomFilterType(left.getTypeFamily());
PCollection<BloomFilter> bloomFilters = left.keys().parallelDo(
"Create bloom filters",
- new CreateBloomFilterFn(vectorSize, nbHash, left.getKeyType()),
+ new CreateBloomFilterFn<>(vectorSize, nbHash, left.getKeyType()),
bloomFilterType);
ReadableData<BloomFilter> bloomData = bloomFilters.asReadable(true);
- FilterKeysWithBloomFilterFn<K, V> filterKeysFn = new FilterKeysWithBloomFilterFn<K, V>(
- bloomData,
- vectorSize, nbHash,
- left.getKeyType());
+ FilterKeysWithBloomFilterFn<K, V> filterKeysFn = new FilterKeysWithBloomFilterFn<>(
+ bloomData, vectorSize, nbHash, left.getKeyType());
- ParallelDoOptions.Builder optionsBuilder = ParallelDoOptions.builder();
- optionsBuilder.sourceTargets(bloomData.getSourceTargets());
+ if (joinType != JoinType.INNER_JOIN && joinType != JoinType.LEFT_OUTER_JOIN) {
+ right = right.parallelDo(
+ "disable deep copy", new DeepCopyDisablerFn<Pair<K, V>>(), right.getPTableType());
+ }
- filteredRightSide = right.parallelDo("Filter right side with BloomFilters",
- filterKeysFn, right.getPTableType(), optionsBuilder.build());
+ ParallelDoOptions options = ParallelDoOptions.builder()
+ .sourceTargets(bloomData.getSourceTargets()).build();
+ PTable<K, V> filteredRightSide = right.parallelDo(
+ "Filter right-side with BloomFilters",
+ filterKeysFn, right.getPTableType(), options);
- return delegateJoinStrategy.join(left, filteredRightSide, joinType);
+ PTable<K, Pair<U, V>> leftJoinedWithFilteredRight = delegateJoinStrategy
+ .join(left, filteredRightSide, joinType);
+
+ if (joinType == JoinType.INNER_JOIN || joinType == JoinType.LEFT_OUTER_JOIN) {
+ return leftJoinedWithFilteredRight;
+ }
+
+ return leftJoinedWithFilteredRight.union(
+ right
+ .parallelDo(
+ "Negatively filter right-side with BloomFilters",
+ FilterFns.not(filterKeysFn), right.getPTableType(), options)
+ .mapValues(
+ "Right outer join: attach null as left-value",
+ new NullKeyFn<U, V>(), leftJoinedWithFilteredRight.getValueType()));
}
/**
@@ -324,4 +343,43 @@
}
+ /**
+ * Converts value into a null-value pair. It is used to convert negatively filtered
+ * right-side values into right outer join part.
+ */
+ private static class NullKeyFn<K, V> extends ExtractKeyFn<K, V> {
+ public NullKeyFn() {
+ super(new MapFn<V, K>() {
+ @Override public K map(V input) {
+ return null;
+ }
+
+ @Override public float scaleFactor() {
+ return 0.0001f;
+ }
+ });
+ }
+ }
+
+ /**
+ * Right and full outer join types are handled by splitting the right-side table (the bigger one)
+ * into two disjunctive streams: negatively filtered (right outer part) and positively filtered.
+ * To prevent concurrent modification Crunch performs a deep copy of such a splitted stream by
+ * default (see {@link DoFn#disableDeepCopy()}), which introduces an extra overhead. Since Bloom
+ * Filter directs every record to exactly one of these streams, making concurrent modification
+ * impossible, we can safely disable this feature. To achieve this we put the {@code right} PTable
+ * through a {@code parallelDo} call with this {@code DoFn}.
+ */
+ private static class DeepCopyDisablerFn<T> extends MapFn<T, T> {
+
+ @Override
+ public T map(T input) {
+ return input;
+ }
+
+ @Override
+ public boolean disableDeepCopy() {
+ return true;
+ }
+ }
}
