package storm.starter;
import storm.starter.bolt.IntermediateRankingsBolt;
import storm.starter.bolt.RollingCountBolt;
import storm.starter.bolt.TotalRankingsBolt;
import storm.starter.util.StormRunner;
import backtype.storm.Config;
import backtype.storm.testing.TestWordSpout;
import backtype.storm.topology.TopologyBuilder;
import backtype.storm.tuple.Fields;
/**
* This topology does a continuous computation of the top N words that the topology has seen in terms of cardinality.
* The top N computation is done in a completely scalable way, and a similar approach could be used to compute things
* like trending topics or trending images on Twitter.
*/
public class RollingTopWords {
private static final int DEFAULT_RUNTIME_IN_SECONDS = 60;
private static final int TOP_N = 5;
private final TopologyBuilder builder;
private final String topologyName;
private final Config topologyConfig;
private final int runtimeInSeconds;
public RollingTopWords() throws InterruptedException {
builder = new TopologyBuilder();
topologyName = "slidingWindowCounts";
topologyConfig = createTopologyConfiguration();
runtimeInSeconds = DEFAULT_RUNTIME_IN_SECONDS;
wireTopology();
}
private static Config createTopologyConfiguration() {
Config conf = new Config();
conf.setDebug(true);
return conf;
}
private void wireTopology() throws InterruptedException {
String spoutId = "wordGenerator";
String counterId = "counter";
String intermediateRankerId = "intermediateRanker";
String totalRankerId = "finalRanker";
builder.setSpout(spoutId, new TestWordSpout(), 5);
builder.setBolt(counterId, new RollingCountBolt(9, 3), 4).fieldsGrouping(spoutId, new Fields("word"));
builder.setBolt(intermediateRankerId, new IntermediateRankingsBolt(TOP_N), 4).fieldsGrouping(counterId,
new Fields("obj"));
builder.setBolt(totalRankerId, new TotalRankingsBolt(TOP_N)).globalGrouping(intermediateRankerId);
}
public void run() throws InterruptedException {
StormRunner.runTopologyLocally(builder.createTopology(), topologyName, topologyConfig, runtimeInSeconds);
}
public static void main(String[] args) throws Exception {
new RollingTopWords().run();
}
}