/*
* 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.ignite.examples.datagrid.starschema;
import java.util.Collection;
import java.util.ConcurrentModificationException;
import java.util.HashMap;
import java.util.Map;
import java.util.concurrent.ThreadLocalRandom;
import javax.cache.Cache;
import org.apache.ignite.Ignite;
import org.apache.ignite.IgniteCache;
import org.apache.ignite.IgniteException;
import org.apache.ignite.Ignition;
import org.apache.ignite.cache.CacheMode;
import org.apache.ignite.cache.query.QueryCursor;
import org.apache.ignite.cache.query.SqlQuery;
import org.apache.ignite.configuration.CacheConfiguration;
import org.apache.ignite.examples.ExampleNodeStartup;
/**
* <a href="http://en.wikipedia.org/wiki/Snowflake_schema">Snowflake Schema</a> is a logical
* arrangement of data in which data is split into {@code dimensions} and {@code facts}.
* <i>Dimensions</i> can be referenced or joined by other <i>dimensions</i> or <i>facts</i>,
* however, <i>facts</i> are generally not referenced by other facts. You can view <i>dimensions</i>
* as your master or reference data, while <i>facts</i> are usually large data sets of events or
* other objects that continuously come into the system and may change frequently. In Ignite
* such architecture is supported via cross-cache queries. By storing <i>dimensions</i> in
* {@link CacheMode#REPLICATED REPLICATED} caches and <i>facts</i> in much larger
* {@link CacheMode#PARTITIONED PARTITIONED} caches you can freely execute distributed joins across
* your whole in-memory data ignite cluster, thus querying your in memory data without any limitations.
* <p>
* In this example we have two <i>dimensions</i>, {@link DimProduct} and {@link DimStore} and
* one <i>fact</i> - {@link FactPurchase}. Queries are executed by joining dimensions and facts
* in various ways.
* <p>
* Remote nodes can be started with {@link ExampleNodeStartup} in another JVM which will
* start node with {@code examples/config/example-ignite.xml} configuration.
*/
public class CacheStarSchemaExample {
/** Partitioned cache name. */
private static final String FACT_CACHE_NAME = CacheStarSchemaExample.class.getSimpleName() + "Fact";
/** Replicated cache name. */
private static final String DIM_STORE_CACHE_NAME = CacheStarSchemaExample.class.getSimpleName() + "DimStore";
/** Replicated cache name. */
private static final String DIM_PROD_CACHE_NAME = CacheStarSchemaExample.class.getSimpleName() + "DimProd";
/** ID generator. */
private static int idGen;
/** DimStore data. */
private static Map<Integer, DimStore> dataStore = new HashMap<>();
/** DimProduct data. */
private static Map<Integer, DimProduct> dataProduct = new HashMap<>();
/**
* Executes example.
*
* @param args Command line arguments, none required.
*/
public static void main(String[] args) {
try (Ignite ignite = Ignition.start("examples/config/example-ignite.xml")) {
System.out.println();
System.out.println(">>> Cache star schema example started.");
CacheConfiguration<Integer, FactPurchase> factCacheCfg = new CacheConfiguration<>(FACT_CACHE_NAME);
factCacheCfg.setCacheMode(CacheMode.PARTITIONED);
factCacheCfg.setIndexedTypes(Integer.class, FactPurchase.class);
CacheConfiguration<Integer, DimStore> dimStoreCacheCfg = new CacheConfiguration<>(DIM_STORE_CACHE_NAME);
dimStoreCacheCfg.setCacheMode(CacheMode.REPLICATED);
dimStoreCacheCfg.setIndexedTypes(Integer.class, DimStore.class);
CacheConfiguration<Integer, DimProduct> dimProdCacheCfg = new CacheConfiguration<>(DIM_PROD_CACHE_NAME);
dimProdCacheCfg.setCacheMode(CacheMode.REPLICATED);
dimProdCacheCfg.setIndexedTypes(Integer.class, DimProduct.class);
// Auto-close cache at the end of the example.
try (IgniteCache<Integer, FactPurchase> factCache = ignite.getOrCreateCache(factCacheCfg);
IgniteCache<Integer, DimStore> dimStoreCache = ignite.getOrCreateCache(dimStoreCacheCfg);
IgniteCache<Integer, DimProduct> dimProdCache = ignite.getOrCreateCache(dimProdCacheCfg)) {
populateDimensions(dimStoreCache, dimProdCache);
populateFacts(factCache);
queryStorePurchases();
queryProductPurchases();
}
finally {
// Distributed cache could be removed from cluster only by #destroyCache() call.
ignite.destroyCache(FACT_CACHE_NAME);
ignite.destroyCache(DIM_STORE_CACHE_NAME);
ignite.destroyCache(DIM_PROD_CACHE_NAME);
}
}
}
/**
* Populate cache with {@code 'dimensions'} which in our case are
* {@link DimStore} and {@link DimProduct} instances.
* @param dimStoreCache Cache of the DimStores to populate.
* @param dimProdCache Cache of the DimProducts to populate.
*
* @throws IgniteException If failed.
*/
private static void populateDimensions(Cache<Integer, DimStore> dimStoreCache,
Cache<Integer, DimProduct> dimProdCache) throws IgniteException {
DimStore store1 = new DimStore(idGen++, "Store1", "12345", "321 Chilly Dr, NY");
DimStore store2 = new DimStore(idGen++, "Store2", "54321", "123 Windy Dr, San Francisco");
// Populate stores.
dimStoreCache.put(store1.getId(), store1);
dimStoreCache.put(store2.getId(), store2);
dataStore.put(store1.getId(), store1);
dataStore.put(store2.getId(), store2);
// Populate products
for (int i = 0; i < 20; i++) {
int id = idGen++;
DimProduct product = new DimProduct(id, "Product" + i, i + 1, (i + 1) * 10);
dimProdCache.put(id, product);
dataProduct.put(id, product);
}
}
/**
* Populate cache with {@code 'facts'}, which in our case are {@link FactPurchase} objects.
* @param factCache Cache to populate.
*
* @throws IgniteException If failed.
*/
private static void populateFacts(Cache<Integer, FactPurchase> factCache) throws IgniteException {
for (int i = 0; i < 100; i++) {
int id = idGen++;
DimStore store = rand(dataStore.values());
DimProduct prod = rand(dataProduct.values());
factCache.put(id, new FactPurchase(id, prod.getId(), store.getId(), (i + 1)));
}
}
/**
* Query all purchases made at a specific store. This query uses cross-cache joins
* between {@link DimStore} objects stored in {@code 'replicated'} cache and
* {@link FactPurchase} objects stored in {@code 'partitioned'} cache.
*
* @throws IgniteException If failed.
*/
private static void queryStorePurchases() {
IgniteCache<Integer, FactPurchase> factCache = Ignition.ignite().cache(FACT_CACHE_NAME);
// All purchases for store1.
// ========================
// Create cross cache query to get all purchases made at store1.
QueryCursor<Cache.Entry<Integer, FactPurchase>> storePurchases = factCache.query(new SqlQuery(
FactPurchase.class,
"from \"" + DIM_STORE_CACHE_NAME + "\".DimStore, \"" + FACT_CACHE_NAME + "\".FactPurchase "
+ "where DimStore.id=FactPurchase.storeId and DimStore.name=?").setArgs("Store1"));
printQueryResults("All purchases made at store1:", storePurchases.getAll());
}
/**
* Query all purchases made at a specific store for 3 specific products.
* This query uses cross-cache joins between {@link DimStore}, {@link DimProduct}
* objects stored in {@code 'replicated'} cache and {@link FactPurchase} objects
* stored in {@code 'partitioned'} cache.
*
* @throws IgniteException If failed.
*/
private static void queryProductPurchases() {
IgniteCache<Integer, FactPurchase> factCache = Ignition.ignite().cache(FACT_CACHE_NAME);
// All purchases for certain product made at store2.
// =================================================
DimProduct p1 = rand(dataProduct.values());
DimProduct p2 = rand(dataProduct.values());
DimProduct p3 = rand(dataProduct.values());
System.out.println("IDs of products [p1=" + p1.getId() + ", p2=" + p2.getId() + ", p3=" + p3.getId() + ']');
// Create cross cache query to get all purchases made at store2
// for specified products.
QueryCursor<Cache.Entry<Integer, FactPurchase>> prodPurchases = factCache.query(new SqlQuery(
FactPurchase.class,
"from \"" + DIM_STORE_CACHE_NAME + "\".DimStore, \"" + DIM_PROD_CACHE_NAME + "\".DimProduct, " +
"\"" + FACT_CACHE_NAME + "\".FactPurchase "
+ "where DimStore.id=FactPurchase.storeId and DimProduct.id=FactPurchase.productId "
+ "and DimStore.name=? and DimProduct.id in(?, ?, ?)")
.setArgs("Store2", p1.getId(), p2.getId(), p3.getId()));
printQueryResults("All purchases made at store2 for 3 specific products:", prodPurchases.getAll());
}
/**
* Print query results.
*
* @param msg Initial message.
* @param res Results to print.
*/
private static <V> void printQueryResults(String msg, Iterable<Cache.Entry<Integer, V>> res) {
System.out.println(msg);
for (Cache.Entry<?, ?> e : res)
System.out.println(" " + e.getValue().toString());
}
/**
* Gets random value from given collection.
*
* @param c Input collection (no {@code null} and not emtpy).
* @return Random value from the input collection.
*/
@SuppressWarnings("UnusedDeclaration")
private static <T> T rand(Collection<? extends T> c) {
if (c == null)
throw new IllegalArgumentException();
int n = ThreadLocalRandom.current().nextInt(c.size());
int i = 0;
for (T t : c) {
if (i++ == n)
return t;
}
throw new ConcurrentModificationException();
}
}