Mastering Apache Storm

Tick tuple

In some use cases, a bolt needs to cache the data for a few seconds before performing some operation, such as cleaning the cache after every 5 seconds or inserting a batch of records into a database in a single request.

The tick tuple is the system-generated (Storm-generated) tuple that we can configure at each bolt level. The developer can configure the tick tuple at the code level while writing a bolt.

We need to overwrite the following method in the bolt to enable the tick tuple:

@Override 
public Map<String, Object> getComponentConfiguration() { 
  Config conf = new Config(); 
  int tickFrequencyInSeconds = 10; 
  conf.put(Config.TOPOLOGY_TICK_TUPLE_FREQ_SECS,   tickFrequencyInSeconds); 
  return conf; 
} 

In the preceding code, we have configured ...