Storm Cassandra Integeration - cassandra

Question

I am newbie in both Storm and Cassandra. I want to use a Bolt to write the strings emitted by a Spout, in a column family in Cassandra. I have read the example here which seems a little bit complex for me, as it uses different classes for writing in the Cassandra DB. Furthermore, I want to know how many times the strings are written in the Cassandra DB. In the example, for me, it is not clear how we can control the number of strings entered in the Cassandra DB?
Simply, I need a Bolt to write the emitted strings by a Spout to a Cassandra column family e.g., 200 records?
Thanks in advance!

Answer 1

You can either use Datastax Cassandra Driver or your can you the storm-cassandra library you posted earlier.
Your requirements is unclear. You only want to store 200 tuples?
Any way, run the topology with sample data and after the stream is finished, query Cassandra and see what is there.
Apache Storm and Apache Cassandra are quite deep and extensive projects. There is no walk around learning them and do sample projects in order to learn.

Answer 2

hope this will help.
/*Main Class */
TopologyBuilder builder = new TopologyBuilder();
Config conf = new Config();
conf.put("cassandra.keyspace", "Storm_Output"); //Key_space name
conf.put("cassandra.nodes","ip-address-of-cassandra-machine");
conf.put("cassandra.port",9042);
//port on which cassandra is running (Default:9042)
builder.setSpout("generator", new RandomSentenceSpout(), 1);
builder.setBolt("counter", new CassandraInsertionBolt(), 1).shuffleGrouping("generator");
builder.setBolt("CassandraBolt",new CassandraWriterBolt(
async(
simpleQuery("INSERT INTO Storm_Output.tanle_name (field1,field2 ) VALUES (?,?);")
.with(
fields("field1","field2 ")
)
)
), 1).globalGrouping("counter");
// Config conf = new Config();
conf.setDebug(true);
conf.setNumWorkers(1);
StormSubmitter.submitTopologyWithProgressBar("Cassnadra-Insertion", conf, builder.createTopology());
/*Bolt sending data for insertion into cassandra */
/*CassandraWriter Bolt */
public void execute(Tuple tuple, BasicOutputCollector basicOutputCollector) {
Random rand=new Random();
basicOutputCollector.emit(new Values(rand.nextInt(20),rand.nextInt(20)));
}
public void declareOutputFields(OutputFieldsDeclarer outputFieldsDeclarer) {
// TODO Auto-generated method stub
outputFieldsDeclarer.declare(new Fields("field1","field2"));
}
}