Apache Storm

Topology Permissions

By default, only the user who deploys the topology has access to admin operations such as rebalance, activate, deactivate, and kill.

The following properties can be set in the topology configuration:

The configurations above can also be set at the cluster level. They will be the default configuration if the topology does not override it.

There is one cluster level configuration that will enable a set of users to be admins for the whole Storm cluster.

Test Spout

import backtype.storm.spout.SpoutOutputCollector;
import backtype.storm.task.TopologyContext;
import backtype.storm.topology.IRichSpout;
import backtype.storm.topology.OutputFieldsDeclarer;
import backtype.storm.tuple.Fields;
import backtype.storm.tuple.Values;

import java.util.Map;

class MySpout implements IRichSpout {
  private int i = 0;
  private Map conf;
  private TopologyContext context;
  private SpoutOutputCollector collector;

  @Override
  public void open(Map conf, TopologyContext context, SpoutOutputCollector collector) {
    this.conf = conf;
    this.context = context;
    this.collector = collector;
  }

  @Override
  public void declareOutputFields(OutputFieldsDeclarer declarer) {
    declarer.declare(new Fields("key", "message"));
  }

  @Override
  public void close() {}

  @Override
  public void activate() {}

  @Override
  public void deactivate() {}

  @Override
  public void nextTuple() {
    if(this.i < 5) {
      this.collector.emit(new Values("key" + i, "val" + i), i);
      this.i++;
    }
  }

  @Override
  public void ack(Object o) {}

  @Override
  public void fail(Object o) {}

  @Override
  public Map<String, Object> getComponentConfiguration() {
    return null;
  }
}