Add use cases scenarios for data migration and data cleaning

README.md

@@ -58,6 +58,23 @@ There are 2 packages with 2 distinct demos
         </ol>
     </li>        
 </ul>
+
+* _usecases_
+<ul>
+    <br/>
+    <br/>
+    Those scenarios examplify how Spark can be used to achieved various real world use-cases
+    <br/>
+    <li> Scenarios
+        <ol>
+            <li> **CrossClusterDataMigration** : this is a sample code to show how to perform effective cross cluster operations. **DO NOT EXECUTE IT**</li>                                                
+            <li> **CrossDCDataMigration** : this is a sample code to show how to perform effective cross data-centers operations. **DO NOT EXECUTE IT**</li>
+            <li> **DataCleaningForPerformers** : in this scenario, we read data from the `performers` table to clean up empty _country_ and reformatting the _born_ and _died_ dates, if present. The data are saved back into Cassandra, thus achieving **perfect data locality**</li>
+            <li> **DisplayPerformersData** : an utility class to show data **before** and **after** the cleaning</li>
+            <li> **MigrateAlbumnsData** : in this scenario, we read source date from `albums` and save them back into a new table `albums_by_country` purposedly built for fast query on contry and year</li>
+        </ol>
+    </li>        
+</ul>
 
 * _weather.data.demo_
 <ul>

src/main/scala/usecases/CrossClusterDataMigration.scala

@@ -0,0 +1,41 @@
+package usecases
+
+import analytics.music.Schema._
+import com.datastax.spark.connector._
+import com.datastax.spark.connector.cql.{CassandraConnectorConf, CassandraConnector}
+import com.datastax.spark.connector.rdd.CassandraTableScanRDD
+import com.datastax.spark.connector.writer.RowWriterFactory
+import org.apache.commons.lang3.StringUtils
+import org.apache.spark.{SparkConf, SparkContext}
+
+import scala.util.matching.Regex
+
+object CrossClusterDataMigration {
+
+  case class Performer(name: String, country: String, gender:String, `type`:String,born:String,died:String, styles:Set[String])
+
+  // DO NOT EXECUTE THIS CLASS, IT IS ONLY A CODE SAMPLE
+  @deprecated
+   def main (args: Array[String]) {
+
+     val confCluster1 = new SparkConf(true)
+       .setAppName("cross_cluster_data_migration")
+       .setMaster("master_ip")
+       .set("spark.cassandra.connection.host", "cluster_1_hostnames")
+
+     val confCluster2 = new SparkConf(true)
+       .setAppName("data_migration")
+       .setMaster("master_ip")
+       .set("spark.cassandra.connection.host", "cluster_2_hostnames")
+
+
+     val sc = new SparkContext(confCluster1)
+
+     sc.cassandraTable[Performer](KEYSPACE,PERFORMERS)
+     .map[Performer](???)
+     .saveToCassandra(KEYSPACE,PERFORMERS)
+     (CassandraConnector(confCluster2),implicitly[RowWriterFactory[Performer]])
+
+   }
+
+ }

src/main/scala/usecases/CrossDCDataMigration.scala

@@ -0,0 +1,39 @@
+package usecases
+
+import analytics.music.Schema._
+import com.datastax.spark.connector._
+import com.datastax.spark.connector.cql.CassandraConnector
+import com.datastax.spark.connector.writer.RowWriterFactory
+import org.apache.spark.{SparkConf, SparkContext}
+
+object CrossDCDataMigration {
+
+  case class Performer(name: String, country: String, gender:String, `type`:String,born:String,died:String, styles:Set[String])
+
+  // DO NOT EXECUTE THIS CLASS, IT IS ONLY A CODE SAMPLE
+  @deprecated
+   def main (args: Array[String]) {
+
+     val confDC1 = new SparkConf(true)
+       .setAppName("cross_DC_data_migration")
+       .setMaster("master_ip")
+       .set("spark.cassandra.connection.host", "DC_1_hostnames")
+       .set("spark.cassandra.connection.local_dc", "DC_1")
+
+     val confDC2 = new SparkConf(true)
+       .setAppName("data_migration")
+       .setMaster("master_ip")
+       .set("spark.cassandra.connection.host", "DC_2_hostnames")
+       .set("spark.cassandra.connection.local_dc", "DC_2")
+
+
+     val sc = new SparkContext(confDC1)
+
+     sc.cassandraTable[Performer](KEYSPACE,PERFORMERS)
+     .map[Performer](???)
+     .saveToCassandra(KEYSPACE,PERFORMERS)
+     (CassandraConnector(confDC2),implicitly[RowWriterFactory[Performer]])
+
+   }
+
+ }

src/main/scala/usecases/DataCleaningForPerformers.scala

@@ -0,0 +1,88 @@
+package usecases
+
+import com.datastax.spark.connector._
+import com.datastax.spark.connector.rdd.CassandraTableScanRDD
+import org.apache.commons.lang3.StringUtils
+import org.apache.spark.{SparkConf, SparkContext}
+import analytics.music.Schema._
+
+import scala.util.matching.Regex
+
+object DataCleaningForPerformers {
+
+  /**
+   *
+   *   CREATE TABLE IF NOT EXISTS performers (
+   *     name TEXT,
+   *     country TEXT,
+   *     gender TEXT,
+   *     type TEXT,
+   *     born TEXT,
+   *     died TEXT,
+   *     styles LIST<TEXT>,
+   *     PRIMARY KEY (name)
+   *   );
+   */
+  val YearPattern = "^[0-9]{4}$".r
+  val YearMonthPattern = "^[0-9]{4}-[0-9]{2}$".r
+  case class Performer(name: String, country: String, gender:String, `type`:String,born:String,died:String, styles:Set[String])
+
+  def main (args: Array[String]) {
+
+    val conf = new SparkConf(true)
+      .setAppName("data_cleaning")
+      .setMaster("local")
+      .set("spark.cassandra.connection.host", "localhost")
+
+    val sc = new SparkContext(conf)
+
+    println("\n ------------ Cleaning data ----------------- \n")
+
+    val cache: CassandraTableScanRDD[Performer] = sc
+      .cassandraTable[Performer](KEYSPACE, PERFORMERS).cache()
+
+    //Fix blank country
+    cache
+      .filter(bean => StringUtils.isBlank(bean.country))
+      .map(bean => (bean.name,"Unknown"))
+      /**
+       * Equivalent to INSERT INTO performers(name,country) VALUES(xxx,yyy)
+       * equivalent to UPDATE performers SET country = yyy WHERE name=xxx
+       */
+      .saveToCassandra(KEYSPACE, PERFORMERS,SomeColumns("name","country"))
+
+    //Normalize born date
+    cache
+      .filter(bean => matchPattern(bean.born,YearPattern))
+      .map(bean => (bean.name,bean.born+"-01-01"))
+      .saveToCassandra(KEYSPACE, PERFORMERS,SomeColumns("name","born"))
+
+    cache
+      .filter(bean => matchPattern(bean.born,YearMonthPattern))
+      .map(bean => (bean.name,bean.born+"-01"))
+      .saveToCassandra(KEYSPACE, PERFORMERS,SomeColumns("name","born"))
+
+    //Normalize died date
+    cache
+      .filter(bean => matchPattern(bean.died,YearPattern))
+      .map(bean => (bean.name,bean.died+"-01-01"))
+      .saveToCassandra(KEYSPACE, PERFORMERS,SomeColumns("name","died"))
+
+    cache
+      .filter(bean => matchPattern(bean.died,YearMonthPattern))
+      .map(bean => (bean.name,bean.died+"-01"))
+      .saveToCassandra(KEYSPACE, PERFORMERS,SomeColumns("name","died"))
+
+    sc.stop()
+  }
+
+  private def matchPattern(input:String, pattern: Regex):Boolean = {
+    if(StringUtils.isBlank(input)) return false
+
+    pattern findFirstIn input match {
+      case Some(c) => true
+      case None => false
+    }
+  }
+
+}

src/main/scala/usecases/DisplayPerformersData.scala

@@ -0,0 +1,49 @@
+package usecases
+
+import analytics.music.Schema._
+import com.datastax.spark.connector._
+import org.apache.commons.lang3.StringUtils
+import org.apache.spark.{SparkConf, SparkContext}
+
+object DisplayPerformersData {
+
+   /**
+    *
+    *   CREATE TABLE IF NOT EXISTS performers (
+    *     name TEXT,
+    *     country TEXT,
+    *     gender TEXT,
+    *     type TEXT,
+    *     born TEXT,
+    *     died TEXT,
+    *     styles LIST<TEXT>,
+    *     PRIMARY KEY (name)
+    *   );
+    */
+
+   case class Performer(name: String, country: String, gender:String, `type`:String,born:String,died:String, styles:Set[String])
+
+   def main (args: Array[String]) {
+
+     val conf = new SparkConf(true)
+       .setAppName("data_display")
+       .setMaster("local")
+       .set("spark.cassandra.connection.host", "localhost")
+
+     val sc = new SparkContext(conf)
+
+
+
+     sc.cassandraTable[Performer](KEYSPACE, PERFORMERS)
+     .filter(bean => StringUtils.isNotBlank(bean.died))
+     .map(bean => bean.died)
+     .collect()
+     .sorted
+     .toSet
+     .foreach[Unit](x => println(x))
+
+     sc.stop()
+   }
+
+
+ }

src/main/scala/usecases/MigrateAlbumsData.scala

@@ -0,0 +1,64 @@
+package usecases
+
+import analytics.music.Schema._
+import com.datastax.spark.connector._
+import com.datastax.spark.connector.cql.CassandraConnector
+import org.apache.spark.{SparkConf, SparkContext}
+
+object MigrateAlbumsData {
+
+  /**
+   *
+   *   CREATE TABLE spark_demo.albums (
+   *       title text PRIMARY KEY,
+   *       country text,
+   *       performer text,
+   *       quality text,
+   *       status text,
+   *       year int
+   *   )
+   *
+   *   CREATE TABLE spark_demo.albums_by_country (
+   *       title text,
+   *       country text,
+   *       performer text,
+   *       quality text,
+   *       status text,
+   *       year int,
+   *       PRIMARY KEY((country,year),title)
+   *   )
+   */
+
+  case class Albums(title: String, country: String, performer:String, quality:String,status:String,year:Int)
+
+   def main (args: Array[String]) {
+
+     val conf = new SparkConf(true)
+       .setAppName("data_migration")
+       .setMaster("local")
+       .set("spark.cassandra.connection.host", "localhost")
+
+     val sc = new SparkContext(conf)
+
+     CassandraConnector(conf).withSessionDo {
+       session => session.execute(
+         """
+           CREATE TABLE IF NOT EXISTS spark_demo.albums_by_country (
+              title text,
+              country text,
+              performer text,
+              quality text,
+              status text,
+              year int,
+              PRIMARY KEY((country,year),title)
+           )
+         """.stripMargin)
+     }
+
+     sc.cassandraTable[Albums](KEYSPACE, ALBUMS)
+     .saveToCassandra(KEYSPACE,ALBUMS_BY_COUNTRY)
+     sc.stop()
+   }
+
+
+ }