hackathonclt

Welcome to hackathonclt!

User Creation

http://dev.hackathonclt.org:5000/

##Machines Machines avaliable to work on:

> slave01.hackathonclt.org

> slave02.hackathonclt.org

> slave03.hackathonclt.org

> slave04.hackathonclt.org

Please spread yourselvs out across the machines

NOTE: if you have any dns issues, speak to staff

Getting Started

Ssh into the server where you can access the retail data stored on the hackathon HDFS cluster.

> ssh [email protected]

and enter the password you specified in user creation.

We made Hive, Spark, and pySpark command-line interfaces available, and included a tool to compile and run simple Scalding scripts on-the-fly.

Hive

Give Hive a whirl and run a sample query:

> hive

Try pasting the following query into the hive command-line interface:

hive> select UPC_NUMBER, ITEM_DESCRIPTION, DEPARTMENT_DESCRIPTION, EXTENDED_PRICE_AMOUNT from hackathon_sample_real limit 10;

This will a launch a (map-only) MapReduce job and return the specified fields for the first ten items in the 'hackathon' table.

Spark

Now give the Spark-shell a test:

> spark-shell

Read in the data and run a simple query that calculates the number of purchases for each upc in the sample data:

val dataRDD = sc.textFile("hdfs://master.hackathonclt.org:8020/sample/data_with_headers/hackathon_data_headers")
val upcs = dataRDD.flatMap(line => line.split("\\|").take(1))
val wordCounts = upcs.map(word => (word, 1)).reduceByKey((a, b) => a + b)
wordCounts.take(10)

pySpark

You can also do the same query using a python version of the Spark shell.

> pyspark

dataRDD = sc.textFile("hdfs://master.hackathonclt.org:8020/sample/data_with_headers/hackathon_data_headers")
upcs = dataRDD.map(lambda line: line.split('|')[0])
wordCounts = upcs.map(lambda word: (word, 1)).reduceByKey(lambda a, b: a + b)
wordCounts.take(10)

Scalding

In addition to the Hive and Spark shells, we're also packaging Eval-tool, a tool to compile and run Scalding scripts without having to create a project. If you create a file called test.scala with the following contents:

import com.twitter.scalding._
import com.tresata.scalding.Dsl._
import com.tresata.scalding.util.ScaldingUtil

(args: Args) => {
  new Job(args) {
    ScaldingUtil.sourceFromArg(args("input"))
      .groupBy('UPC_NUMBER) { _.size }
      .write(ScaldingUtil.sourceFromArg(args("output")))
  }
}

you can run a query on the data set sample from the command-line:

> eval-tool test.scala --hdfs --input bsv%/sample/data_with_headers/hackathon_data_headers --output bsv%upc_counts

This will generate a bar-separated file called 'upc_counts' in your HDFS home directory, containing the upc numbers along with their total counts.

To access your HDFS location, you need to use hadoop fs commands (some reference: http://www.folkstalk.com/2013/09/hadoop-fs-shell-command-example-tutorial.html). For example, to take a look at your home directory on HDFS, use

> hadoop fs -ls

or

> hadoop fs -ls /user/username

##Job Tracker http://master.hackathonclt.org:50030

##Spark Job Tracker http://master.hackathonclt.org:8080

##Namenode information http://master.hackathonclt.org:50070

##Data Dictionary UPC_NUMBER long unique product code of item MASTER_UPC_NUMBER long master UPC number, UPC numbers go under this
ITEM_DESCRIPTION string describes item DEPARTMENT_NUMBER long department number DEPARTMENT_DESCRIPTION string describes department CATEGORY_NUMBER long category number of item CATEGORY_DESCRIPTION string describes category of item SUBCATEGORY_NUMBER long subcategory of item SUBCATEGORY_DESCRIPTION string describes subcategory of item RECEIPT_NUMBER string recipe number of the purchase ITEM_QUANTITY long how many items was bought EXTENDED_PRICE_AMOUNT float actual sale per swipe DISCOUNT_QUANTITY float number of coupons applied EXTENDED_DISCOUNT_AMOUNT float amount discounted TENDER_AMOUNT float amount tendered by the customer for the transaction TRANSACTION_DATETIME string date of transaction EXPRESS_LANE long flag of whether the purchase was through Express Lane, tagged to recipe number. 1 mean yes, 0 means no HHID string house hold id