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Posted to commits@mahout.apache.org by sr...@apache.org on 2011/07/25 15:40:22 UTC
svn commit: r1150696 - in /mahout/trunk: integration/pom.xml
integration/src/main/java/org/apache/mahout/cf/taste/impl/model/cassandra/
integration/src/main/java/org/apache/mahout/cf/taste/impl/model/cassandra/CassandraDataModel.java
pom.xml
Author: srowen
Date: Mon Jul 25 13:40:21 2011
New Revision: 1150696
URL: http://svn.apache.org/viewvc?rev=1150696&view=rev
Log:
MAHOUT-770 Cassandra data models support
Added:
mahout/trunk/integration/src/main/java/org/apache/mahout/cf/taste/impl/model/cassandra/
mahout/trunk/integration/src/main/java/org/apache/mahout/cf/taste/impl/model/cassandra/CassandraDataModel.java
Modified:
mahout/trunk/integration/pom.xml
mahout/trunk/pom.xml
Modified: mahout/trunk/integration/pom.xml
URL: http://svn.apache.org/viewvc/mahout/trunk/integration/pom.xml?rev=1150696&r1=1150695&r2=1150696&view=diff
==============================================================================
--- mahout/trunk/integration/pom.xml (original)
+++ mahout/trunk/integration/pom.xml Mon Jul 25 13:40:21 2011
@@ -145,6 +145,16 @@
<groupId>org.mongodb</groupId>
<artifactId>bson</artifactId>
</dependency>
+
+ <dependency>
+ <groupId>org.apache.cassandra</groupId>
+ <artifactId>cassandra-all</artifactId>
+ </dependency>
+
+ <dependency>
+ <groupId>me.prettyprint</groupId>
+ <artifactId>hector-core</artifactId>
+ </dependency>
<dependency>
<groupId>org.slf4j</groupId>
Added: mahout/trunk/integration/src/main/java/org/apache/mahout/cf/taste/impl/model/cassandra/CassandraDataModel.java
URL: http://svn.apache.org/viewvc/mahout/trunk/integration/src/main/java/org/apache/mahout/cf/taste/impl/model/cassandra/CassandraDataModel.java?rev=1150696&view=auto
==============================================================================
--- mahout/trunk/integration/src/main/java/org/apache/mahout/cf/taste/impl/model/cassandra/CassandraDataModel.java (added)
+++ mahout/trunk/integration/src/main/java/org/apache/mahout/cf/taste/impl/model/cassandra/CassandraDataModel.java Mon Jul 25 13:40:21 2011
@@ -0,0 +1,458 @@
+/**
+ * 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.mahout.cf.taste.impl.model.cassandra;
+
+import com.google.common.base.Preconditions;
+import me.prettyprint.cassandra.model.HColumnImpl;
+import me.prettyprint.cassandra.serializers.BytesArraySerializer;
+import me.prettyprint.cassandra.serializers.FloatSerializer;
+import me.prettyprint.cassandra.serializers.LongSerializer;
+import me.prettyprint.cassandra.service.OperationType;
+import me.prettyprint.hector.api.Cluster;
+import me.prettyprint.hector.api.ConsistencyLevelPolicy;
+import me.prettyprint.hector.api.HConsistencyLevel;
+import me.prettyprint.hector.api.Keyspace;
+import me.prettyprint.hector.api.beans.ColumnSlice;
+import me.prettyprint.hector.api.beans.HColumn;
+import me.prettyprint.hector.api.factory.HFactory;
+import me.prettyprint.hector.api.mutation.Mutator;
+import me.prettyprint.hector.api.query.ColumnQuery;
+import me.prettyprint.hector.api.query.CountQuery;
+import me.prettyprint.hector.api.query.SliceQuery;
+import org.apache.mahout.cf.taste.common.NoSuchItemException;
+import org.apache.mahout.cf.taste.common.NoSuchUserException;
+import org.apache.mahout.cf.taste.common.Refreshable;
+import org.apache.mahout.cf.taste.common.TasteException;
+import org.apache.mahout.cf.taste.impl.common.Cache;
+import org.apache.mahout.cf.taste.impl.common.FastIDSet;
+import org.apache.mahout.cf.taste.impl.common.LongPrimitiveIterator;
+import org.apache.mahout.cf.taste.impl.common.Retriever;
+import org.apache.mahout.cf.taste.impl.model.GenericItemPreferenceArray;
+import org.apache.mahout.cf.taste.impl.model.GenericUserPreferenceArray;
+import org.apache.mahout.cf.taste.model.DataModel;
+import org.apache.mahout.cf.taste.model.PreferenceArray;
+
+import java.io.Closeable;
+import java.util.Collection;
+import java.util.List;
+import java.util.concurrent.atomic.AtomicReference;
+
+/**
+ * <p>A {@link DataModel} based on a Cassandra keyspace. By default it uses keyspace "recommender" but this
+ * can be configured. Create the keyspace before using this class; this can be done on the Cassandra command
+ * line with a command linke {@code create keyspace recommender;}.</p>
+ *
+ * <p>Within the keyspace, this model uses four column families:</p>
+ *
+ * <p>First, it uses a column family called "users". This is keyed by the user ID as an 8-byte long.
+ * It contains a column for every preference the user expresses. The column name is item ID, again as
+ * an 8-byte long, and value is a floating point value represnted as an IEEE 32-bit floating poitn value.</p>
+ *
+ * <p>It uses an analogous column family called "items" for the same data, but keyed by item ID rather
+ * than user ID. In this column family, column names are user IDs instead.</p>
+ *
+ * <p>It uses a column family called "userIDs" as well, with an identical schema. It has one row under key
+ * 0. IT contains a column for every user ID in th emodel. It has no values.</p>
+ *
+ * <p>Finally it also uses an analogous column family "itemIDs" containing item IDs.</p>
+ *
+ * <p>Each of these four column families needs to be created ahead of time. Again the
+ * Cassandra CLI can be used to do so, with commands like {@code create column family users;}.</p>
+ *
+ * <p>Note that this thread uses a long-lived Cassandra client which will run until terminated. You
+ * must {@link #close()} this implementation when done or the JVM will not terminate.</p>
+ *
+ * <p>This implementation still relies heavily on reading data into memory and caching,
+ * as it remains too data-intensive to be effective even against Cassandra. It will take some time to
+ * "warm up" as the first few requests will block loading user and item data into caches. This is still going
+ * to send a great deal of query traffic to Cassandra. It would be advisable to employ caching wrapper
+ * classes in your implementation, like {@link org.apache.mahout.cf.taste.impl.recommender.CachingRecommender}
+ * or {@link org.apache.mahout.cf.taste.impl.similarity.CachingItemSimilarity}.</p>
+ */
+public final class CassandraDataModel implements DataModel, Closeable {
+
+ /** Default Cassandra host. Default: localhost */
+ private static final String DEFAULT_HOST = "localhost";
+
+ /** Default Cassandra port. Default: 9160 */
+ private static final int DEFAULT_PORT = 9160;
+
+ /** Default Cassandra keyspace. Default: recommender */
+ private static final String DEFAULT_KEYSPACE = "recommender";
+
+ static final String USERS_CF = "users";
+ static final String ITEMS_CF = "items";
+ static final String USER_IDS_CF = "userIDs";
+ static final String ITEM_IDS_CF = "itemIDs";
+ private static final long ID_ROW_KEY = 0L;
+ private static final byte[] EMPTY = new byte[0];
+
+ private final Cluster cluster;
+ private final Keyspace keyspace;
+ private final Cache<Long,PreferenceArray> userCache;
+ private final Cache<Long,PreferenceArray> itemCache;
+ private final Cache<Long,FastIDSet> itemIDsFromUserCache;
+ private final Cache<Long,FastIDSet> userIDsFromItemCache;
+ private final AtomicReference<Integer> userCountCache;
+ private final AtomicReference<Integer> itemCountCache;
+
+ /**
+ * Uses the standard Cassandra host and port (localhost:9160), and keyspace name ("recommender").
+ */
+ public CassandraDataModel() {
+ this(DEFAULT_HOST, DEFAULT_PORT, DEFAULT_KEYSPACE);
+ }
+
+ /**
+ * @param host Cassandra server host name
+ * @param port Cassandra server port
+ * @param keyspaceName name of Cassandra keyspace to use
+ */
+ public CassandraDataModel(String host, int port, String keyspaceName) {
+
+ Preconditions.checkNotNull(host);
+ Preconditions.checkArgument(port > 0);
+ Preconditions.checkNotNull(keyspaceName);
+
+ cluster = HFactory.getOrCreateCluster(CassandraDataModel.class.getSimpleName(), host + ':' + port);
+ keyspace = HFactory.createKeyspace(keyspaceName, cluster);
+ keyspace.setConsistencyLevelPolicy(new OneConsistencyLevelPolicy());
+
+ userCache = new Cache<Long,PreferenceArray>(new UserPrefArrayRetriever(), 1 << 20);
+ itemCache = new Cache<Long,PreferenceArray>(new ItemPrefArrayRetriever(), 1 << 20);
+ itemIDsFromUserCache = new Cache<Long,FastIDSet>(new ItemIDsFromUserRetriever(), 1 << 20);
+ userIDsFromItemCache = new Cache<Long,FastIDSet>(new UserIDsFromItemRetriever(), 1 << 20);
+ userCountCache = new AtomicReference<Integer>(null);
+ itemCountCache = new AtomicReference<Integer>(null);
+ }
+
+ @Override
+ public LongPrimitiveIterator getUserIDs() {
+ SliceQuery<Long,Long,?> query = buildNoValueSliceQuery(USER_IDS_CF);
+ query.setKey(ID_ROW_KEY);
+ FastIDSet userIDs = new FastIDSet();
+ for (HColumn<Long,?> userIDColumn : query.execute().get().getColumns()) {
+ userIDs.add(userIDColumn.getName());
+ }
+ return userIDs.iterator();
+ }
+
+ @Override
+ public PreferenceArray getPreferencesFromUser(long userID) throws TasteException {
+ return userCache.get(userID);
+ }
+
+ @Override
+ public FastIDSet getItemIDsFromUser(long userID) throws TasteException {
+ return itemIDsFromUserCache.get(userID);
+ }
+
+ @Override
+ public LongPrimitiveIterator getItemIDs() {
+ SliceQuery<Long,Long,?> query = buildNoValueSliceQuery(ITEM_IDS_CF);
+ query.setKey(ID_ROW_KEY);
+ FastIDSet itemIDs = new FastIDSet();
+ for (HColumn<Long,?> itemIDColumn : query.execute().get().getColumns()) {
+ itemIDs.add(itemIDColumn.getName());
+ }
+ return itemIDs.iterator();
+ }
+
+ @Override
+ public PreferenceArray getPreferencesForItem(long itemID) throws TasteException {
+ return itemCache.get(itemID);
+ }
+
+ @Override
+ public Float getPreferenceValue(long userID, long itemID) {
+ ColumnQuery<Long,Long,Float> query =
+ HFactory.createColumnQuery(keyspace, LongSerializer.get(), LongSerializer.get(), FloatSerializer.get());
+ query.setColumnFamily(USERS_CF);
+ query.setKey(userID);
+ query.setName(itemID);
+ HColumn<Long,Float> column = query.execute().get();
+ return column == null ? null : column.getValue();
+ }
+
+ @Override
+ public Long getPreferenceTime(long userID, long itemID) {
+ ColumnQuery<Long,Long,?> query =
+ HFactory.createColumnQuery(keyspace, LongSerializer.get(), LongSerializer.get(), BytesArraySerializer.get());
+ query.setColumnFamily(USERS_CF);
+ query.setKey(userID);
+ query.setName(itemID);
+ HColumn<Long,?> result = query.execute().get();
+ return result == null ? null : result.getClock();
+ }
+
+ @Override
+ public int getNumItems() {
+ Integer itemCount = itemCountCache.get();
+ if (itemCount == null) {
+ CountQuery<Long,Long> countQuery =
+ HFactory.createCountQuery(keyspace, LongSerializer.get(), LongSerializer.get());
+ countQuery.setKey(ID_ROW_KEY);
+ countQuery.setColumnFamily(ITEM_IDS_CF);
+ countQuery.setRange(null, null, Integer.MAX_VALUE);
+ itemCount = countQuery.execute().get();
+ itemCountCache.set(itemCount);
+ }
+ return itemCount;
+ }
+
+ @Override
+ public int getNumUsers() {
+ Integer userCount = userCountCache.get();
+ if (userCount == null) {
+ CountQuery<Long,Long> countQuery =
+ HFactory.createCountQuery(keyspace, LongSerializer.get(), LongSerializer.get());
+ countQuery.setKey(ID_ROW_KEY);
+ countQuery.setColumnFamily(USER_IDS_CF);
+ countQuery.setRange(null, null, Integer.MAX_VALUE);
+ userCount = countQuery.execute().get();
+ userCountCache.set(userCount);
+ }
+ return userCount;
+ }
+
+ @Override
+ public int getNumUsersWithPreferenceFor(long itemID) throws TasteException {
+ /*
+ CountQuery<Long,Long> query = HFactory.createCountQuery(keyspace, LongSerializer.get(), LongSerializer.get());
+ query.setColumnFamily(ITEMS_CF);
+ query.setKey(itemID);
+ query.setRange(null, null, Integer.MAX_VALUE);
+ return query.execute().get();
+ */
+ return userIDsFromItemCache.get(itemID).size();
+ }
+
+ @Override
+ public int getNumUsersWithPreferenceFor(long itemID1, long itemID2) throws TasteException {
+ FastIDSet userIDs1 = userIDsFromItemCache.get(itemID1);
+ FastIDSet userIDs2 = userIDsFromItemCache.get(itemID2);
+ return userIDs1.intersectionSize(userIDs2);
+ }
+
+ @Override
+ public void setPreference(long userID, long itemID, float value) {
+
+ if (Float.isNaN(value)) {
+ value = 1.0f;
+ }
+
+ long now = System.currentTimeMillis();
+
+ Mutator<Long> mutator = HFactory.createMutator(keyspace, LongSerializer.get());
+
+ HColumn<Long,Float> itemForUsers = new HColumnImpl<Long,Float>(LongSerializer.get(), FloatSerializer.get());
+ itemForUsers.setName(itemID);
+ itemForUsers.setClock(now);
+ itemForUsers.setValue(value);
+ mutator.addInsertion(userID, USERS_CF, itemForUsers);
+
+ HColumn<Long,Float> userForItems = new HColumnImpl<Long,Float>(LongSerializer.get(), FloatSerializer.get());
+ userForItems.setName(userID);
+ userForItems.setClock(now);
+ userForItems.setValue(value);
+ mutator.addInsertion(itemID, ITEMS_CF, userForItems);
+
+ HColumn<Long,byte[]> userIDs = new HColumnImpl<Long,byte[]>(LongSerializer.get(), BytesArraySerializer.get());
+ userIDs.setName(userID);
+ userIDs.setClock(now);
+ userIDs.setValue(EMPTY);
+ mutator.addInsertion(ID_ROW_KEY, USER_IDS_CF, userIDs);
+
+ HColumn<Long,byte[]> itemIDs = new HColumnImpl<Long,byte[]>(LongSerializer.get(), BytesArraySerializer.get());
+ itemIDs.setName(itemID);
+ itemIDs.setClock(now);
+ itemIDs.setValue(EMPTY);
+ mutator.addInsertion(ID_ROW_KEY, ITEM_IDS_CF, itemIDs);
+
+ mutator.execute();
+ }
+
+ @Override
+ public void removePreference(long userID, long itemID) {
+ Mutator<Long> mutator = HFactory.createMutator(keyspace, LongSerializer.get());
+ mutator.addDeletion(userID, USERS_CF, itemID, LongSerializer.get());
+ mutator.addDeletion(itemID, ITEMS_CF, userID, LongSerializer.get());
+ mutator.execute();
+ // Not deleting from userIDs, itemIDs though
+ }
+
+ /**
+ * @return true
+ */
+ @Override
+ public boolean hasPreferenceValues() {
+ return true;
+ }
+
+ /**
+ * @return Float#NaN
+ */
+ @Override
+ public float getMaxPreference() {
+ return Float.NaN;
+ }
+
+ /**
+ * @return Float#NaN
+ */
+ @Override
+ public float getMinPreference() {
+ return Float.NaN;
+ }
+
+ @Override
+ public void refresh(Collection<Refreshable> alreadyRefreshed) {
+ userCache.clear();
+ }
+
+ @Override
+ public String toString() {
+ return "CassandraDataModel[" + keyspace + ']';
+ }
+
+ @Override
+ public void close() {
+ HFactory.shutdownCluster(cluster);
+ }
+
+
+ private SliceQuery<Long,Long,byte[]> buildNoValueSliceQuery(String cf) {
+ SliceQuery<Long,Long,byte[]> query =
+ HFactory.createSliceQuery(keyspace, LongSerializer.get(), LongSerializer.get(), BytesArraySerializer.get());
+ query.setColumnFamily(cf);
+ query.setRange(null, null, false, Integer.MAX_VALUE);
+ return query;
+ }
+
+ private SliceQuery<Long,Long,Float> buildValueSliceQuery(String cf) {
+ SliceQuery<Long,Long,Float> query =
+ HFactory.createSliceQuery(keyspace, LongSerializer.get(), LongSerializer.get(), FloatSerializer.get());
+ query.setColumnFamily(cf);
+ query.setRange(null, null, false, Integer.MAX_VALUE);
+ return query;
+ }
+
+
+ private static final class OneConsistencyLevelPolicy implements ConsistencyLevelPolicy {
+ @Override
+ public HConsistencyLevel get(OperationType op) {
+ return HConsistencyLevel.ONE;
+ }
+
+ @Override
+ public HConsistencyLevel get(OperationType op, String cfName) {
+ return HConsistencyLevel.ONE;
+ }
+ }
+
+ private final class UserPrefArrayRetriever implements Retriever<Long, PreferenceArray> {
+ @Override
+ public PreferenceArray get(Long userID) throws TasteException {
+ SliceQuery<Long,Long,Float> query = buildValueSliceQuery(USERS_CF);
+ query.setKey(userID);
+
+ ColumnSlice<Long,Float> result = query.execute().get();
+ if (result == null) {
+ throw new NoSuchUserException(userID);
+ }
+ List<HColumn<Long,Float>> itemIDColumns = result.getColumns();
+ if (itemIDColumns.isEmpty()) {
+ throw new NoSuchUserException(userID);
+ }
+ int size = itemIDColumns.size();
+ PreferenceArray prefs = new GenericUserPreferenceArray(size);
+ prefs.setUserID(0, userID);
+ for (int i = 0; i < size; i++) {
+ HColumn<Long,Float> itemIDColumn = itemIDColumns.get(i);
+ prefs.setItemID(i, itemIDColumn.getName());
+ prefs.setValue(i, itemIDColumn.getValue());
+ }
+ return prefs;
+ }
+ }
+
+ private final class ItemPrefArrayRetriever implements Retriever<Long, PreferenceArray> {
+ @Override
+ public PreferenceArray get(Long itemID) throws TasteException {
+ SliceQuery<Long,Long,Float> query = buildValueSliceQuery(ITEMS_CF);
+ query.setKey(itemID);
+ ColumnSlice<Long,Float> result = query.execute().get();
+ if (result == null) {
+ throw new NoSuchItemException(itemID);
+ }
+ List<HColumn<Long,Float>> userIDColumns = result.getColumns();
+ if (userIDColumns.isEmpty()) {
+ throw new NoSuchItemException(itemID);
+ }
+ int size = userIDColumns.size();
+ PreferenceArray prefs = new GenericItemPreferenceArray(size);
+ prefs.setItemID(0, itemID);
+ for (int i = 0; i < size; i++) {
+ HColumn<Long,Float> userIDColumn = userIDColumns.get(i);
+ prefs.setUserID(i, userIDColumn.getName());
+ prefs.setValue(i, userIDColumn.getValue());
+ }
+ return prefs;
+ }
+ }
+
+ private final class UserIDsFromItemRetriever implements Retriever<Long, FastIDSet> {
+ @Override
+ public FastIDSet get(Long itemID) throws TasteException {
+ SliceQuery<Long,Long,byte[]> query = buildNoValueSliceQuery(ITEMS_CF);
+ query.setKey(itemID);
+ ColumnSlice<Long,byte[]> result = query.execute().get();
+ if (result == null) {
+ throw new NoSuchItemException(itemID);
+ }
+ List<HColumn<Long,byte[]>> columns = result.getColumns();
+ FastIDSet userIDs = new FastIDSet(columns.size());
+ for (HColumn<Long,?> userIDColumn : columns) {
+ userIDs.add(userIDColumn.getName());
+ }
+ return userIDs;
+ }
+ }
+
+ private final class ItemIDsFromUserRetriever implements Retriever<Long, FastIDSet> {
+ @Override
+ public FastIDSet get(Long userID) throws TasteException {
+ SliceQuery<Long,Long,byte[]> query = buildNoValueSliceQuery(USERS_CF);
+ query.setKey(userID);
+ FastIDSet itemIDs = new FastIDSet();
+ ColumnSlice<Long,byte[]> result = query.execute().get();
+ if (result == null) {
+ throw new NoSuchUserException(userID);
+ }
+ List<HColumn<Long,byte[]>> columns = result.getColumns();
+ if (columns.isEmpty()) {
+ throw new NoSuchUserException(userID);
+ }
+ for (HColumn<Long,?> itemIDColumn : columns) {
+ itemIDs.add(itemIDColumn.getName());
+ }
+ return itemIDs;
+ }
+ }
+
+}
Modified: mahout/trunk/pom.xml
URL: http://svn.apache.org/viewvc/mahout/trunk/pom.xml?rev=1150696&r1=1150695&r2=1150696&view=diff
==============================================================================
--- mahout/trunk/pom.xml (original)
+++ mahout/trunk/pom.xml Mon Jul 25 13:40:21 2011
@@ -365,6 +365,18 @@
<version>2.5</version>
</dependency>
+ <dependency>
+ <groupId>org.apache.cassandra</groupId>
+ <artifactId>cassandra-all</artifactId>
+ <version>0.8.1</version>
+ </dependency>
+
+ <dependency>
+ <groupId>me.prettyprint</groupId>
+ <artifactId>hector-core</artifactId>
+ <version>0.8.0-1</version>
+ </dependency>
+
</dependencies>
</dependencyManagement>
<build>