Spark Recipes

Notice: Confluent Platform is the trademark and property of Confluent Inc. Kafka 0.90 comes with Kafka Connect. Kafka Connect is a tool for scalably and reliably streaming data between Apache Kafka and other data systems. It makes it simple to quickly define...

Spark Streaming is a microbatch based streaming library. What that means is that streaming data is divided into batches based on time slice called batch interval. Every batch gets converted into an RDD and this continous stream of RDDs is represented as DStream....

Let's use house as a vector with following features: Square footage Last sold price Lot Size Number of rooms Number of bath rooms year built zip code Tennis Court Pool Jacuzzi Sports Court Now let's put some values Square Footage => 4450 Last Sold price => 2600000 Lot...

Hive has 5 parts HiveQL as the language Hive as a command-line tools which you can call client Hive MetaStore (port:9083) Hive warehouse HiveServer2 (port: 10000) HiveQL HiveQL is a query language similar to SQL but supports limited SQL functions. It also adds few...

To connect to S3 from Spark you need two environment variables for security credentials and they are: AWS_ACCESS_KEY AWS_SECRET_ACCESS_KEY There are three ways to set them up. 1. In .bashrc file, add following two lines at the end. Replace these dummy values with the...

Spark ML is a new library which uses dataframes as it's first class citizen as opposed to RDD. Another feature of Spark ML is that it helps in combining multiple machine learning algorithms into a single pipeline. You can read more about dataframes here. Spark ML uses...

Accumulators are Spark's answer to MapReduce counters but they do much more than that. Let's first start with a simple example which uses accumulators for simple count. scala> val ac = sc.accumulator(0) scala> val words =...

Correlation is a relationship among two variables so if one changes, other also changes. Correlation measures how strong this change is from 0 t0 1. 0 means there is no correlation at all while one means perfect correlation i.e. if first variable become double, second...

Apache Spark installation comes bundled with spark-ec2 script which makes it easy to create Spark instances on EC2. This recipe will cover connecting to EC2 using this script. Login to your Amazon AWS account Click on Security Credentials under your account name in...

So far in Spark, JdbcRDD has been the right way to connect with a relational data source. In Spark 1.4 onwards there is an inbuilt datasource available to connect to a jdbc source using dataframes. Dataframe Spark introduced dataframes in version 1.3 and enriched...

For Spark 1.3 onwards, JdbcRDD is not recommended as DataFrames have support to load JDBC. Let us look at a simple example in this recipe. Using JdbcRDD with Spark is slightly confusing, so I thought about putting a simple use case to explain the functionality. Most...

For Spark 1.3 onward, JdbcRDD is not recommended as DataFrames have support to load JDBC. Let us look at a simple example in this recipe. Using JdbcRDD with Spark is slightly confusing, so I thought about putting a simple use case to explain the functionality. Most...

This recipe works with Spark 1.3 onward. Apache Parquet as a file format has garnered significant attention recently. Let's say you have a table with 100 columns, most of the time you are going to access 3-10 columns. In Row oriented format all columns are scanned...

Apache Spark 1.3 introduced a new concept called DataFrames and it got further developed in version 1.4. Dataframes also complement project Tungsten, a new initiative to improve CPU performance in Spark. Motivation behind DataFrames Spark so far has had a...

Spark SQL is great at executing SQL but sometimes you want to stick to the RDD level. Then comes the role of DSL. Sometimes how exactly to use Spark with DSL becomes confusing. This recipe is an attempt to reduce that. Let's get done with pleasantries first, i.e.,...

This recipe is inspired by http://spark.apache.org/docs/latest/sql-programming-guide.html#programmatically-specifying-the-schema and all rights are owned by their respective owners. In Spark SQL, the best way to create SchemaRDD is by using scala case class. Spark...

Please note SchemaRDD in Spark 1.2 has been replaced by DataFrames in Spark 1.3. SqlContext can be used to load underlying data in JSON and Parquet format like: scala> import sqlContext = new org.apache.spark.sql.SQLContext(sc) scala> import sqlContext._ scala> val...

This recipe is based on the Databricks spark-avro library and all rights to this library are owned by Databricks. Download the spark-avro library: $wget https://github.com/databricks/spark-avro/archive/master.zip $unzip master.zip $cd spark-avro-master $sbt >package...

Spark SQL does not support date type, so things like duration become tough to calculate. That said, in Spark everything is RDD. So that's a hidden weapon which can always be used when higher level functionality is limited. Let's take a case where we are getting two...

RDD being a unit of compute in Spark is capable of doing all complex operations which traditionally are done using complex queries in databases. It's sometimes difficult to get the exact steps to perform these operations, so this blog is an attempt in that direction...

Compression has an important role to play in Big Data technologies. It makes both storage and transport of data more efficient. Then why are so many compression formats, and what are the things we have to balance while making a decision about which compression format...

This recipe works with Spark 1.2. For Spark 1.3 version, please click here. Apache Parquet, as a file format, has garnered significant attention recently. Let's say you have a table with 100 columns, most of the time you are going to access 3-10 columns. In row...

While loading a RDD from source data, there are two choices which look similar. scala> val movies = sc.textFile("movies") scala> val movies = sc.wholeTextFiles("movies") sc.textFile SparkContext's TextFile method, i.e., sc.textFile in Spark Shell, creates a RDD with...

Using JdbcRDD with Spark is slightly confusing, so I thought about putting a simple use case to explain the functionality. Most probably you'll use it with spark-submit but I have put it here in spark-shell to illustrate easier. Database Preparation We are going to...

There are two ways to create context in Spark SQL: SqlContext: scala> import org.apache.spark.sql._ scala> var sqlContext = new SQLContext(sc) HiveContext: scala> import org.apache.spark.sql.hive._ scala> val hc = new HiveContext(sc) Though most of the code examples...