Data Migration and Analytics - Beginning Apache Cassandra Development - page 148

In this section, we will create a Cassandra table to store tweets and use Apache Pig to
load tweets in Cassandra.

1. First let's create a keyspace and table in Cassandra as follows:

create keyspace twitter with replication =
{'class':'SimpleStrategy','replication_factor':1};
use twitter;
create table twitterdata(screen_name text
primary key, tweetdate text, body text);

2. Start Pig in local mode and load tweets:

tweets = LOAD '/home/vivek/tweets' USING
PigStorage('\ua001') as
(date:chararray,screen_name:chararray,body:chararray);

You may need to change the directory path as per your settings.

3. Register apache-cassandra-2.0.4.jar :

register '$CASSANDRA_HOME/lib/
apache-cassandra-2.0.4.jar';
define CqlStorage
org.apache.cassandra.hadoop.pig.CqlStorage();

4. Generate a tuple using TOTUPLE :

data_to = FOREACH tweets GENERATE
TOTUPLE(TOTUPLE('screen_name',screen_name)),TOTUPLE(TOTUPLE('tweetdate',date),
body);

5. Finally, store the generated tuples in Cassandra using the CqlStor-

age function:

STORE data_to INTO 'cql://twitter/
twitterdata?output_query=update twitterdata
set tweetdate %3D%3F,body %3D%3F' USING
CqlStorage();