org.thales.punch.libraries.storm.bolt

Class RythmerNode

java.lang.Object

org.thales.punch.libraries.storm.api.BaseProcessingNode

org.thales.punch.libraries.storm.bolt.RythmerNode

All Implemented Interfaces:

Serializable, org.apache.storm.task.IBolt, org.apache.storm.topology.IComponent, org.apache.storm.topology.IRichBolt

public class RythmerNode
extends org.thales.punch.libraries.storm.api.BaseProcessingNode

The rythmer bolt emits messages according to a provided timestamp. It can be used to replay some data in a way to reproduce a given time sequence, for example the one that was observed when the data was first received in a PunchPlatform topology.

In order to reproduce the same time pacing between subsequent messages, the RytmerBolt uses a busy wait loop. It uses a single thread. It replays 1000 events per seconds with an error of less than 10%.

Note that the RythmerBolt expects to received tuple sorted in time. If you need to replay some data, make sure you get an ordered list. This can easily be achieved by preparing your data and make it available in a file or in a Kafka topic for example.

The rythmer bolt expects the following parameters:

field name	mandatory	type	default	comment
timestamp_field	no	string	timestamp	the storm field where the input timestamp is expected
threshold	no	long	0	the number of input tuple required before starting the replay
date_format	no	string	"yyyy-MM-dd hh:mm:ss.SSSS"	the expected timestamp format

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
boolean	isRunning use to verify if the consummer is aldreay running

Fields inherited from class org.thales.punch.libraries.storm.api.BaseProcessingNode

ackRate, collector, componentId, every, failRate, metricContext, nodeSettings, topologyContext, traversalTime

Constructor Summary

Constructors

Constructor and Description
RythmerNode(org.thales.punch.libraries.storm.api.NodeSettings config)

Method Summary

Modifier and Type	Method and Description
void	prepare(Map stormConf, org.apache.storm.task.TopologyContext context, org.apache.storm.task.OutputCollector collector)
void	process(org.apache.storm.tuple.Tuple tuple) Before sending the tuple to the consumer, the time difference between the previous message is calculated.

Methods inherited from class org.thales.punch.libraries.storm.api.BaseProcessingNode

ack, cleanup, declareOutputFields, enrichAndForwardMonitoringTuple, execute, fail, getComponentConfiguration, getNewPoint

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

isRunning

public boolean isRunning

use to verify if the consummer is aldreay running

Constructor Detail

RythmerNode

public RythmerNode(org.thales.punch.libraries.storm.api.NodeSettings config)

Parameters:

config - the bolt configuration

Method Detail

prepare

public void prepare(Map stormConf,
                    org.apache.storm.task.TopologyContext context,
                    org.apache.storm.task.OutputCollector collector)

Specified by:

prepare in interface org.apache.storm.task.IBolt

Overrides:

prepare in class org.thales.punch.libraries.storm.api.BaseProcessingNode

process

public void process(org.apache.storm.tuple.Tuple tuple)

Before sending the tuple to the consumer, the time difference between the previous message is calculated. Tuple and the offset is set to the LinkedBlockingQueue. The execute check if the consummer is running. If not, the MessageConsummer thread is started.

Specified by:

process in class org.thales.punch.libraries.storm.api.BaseProcessingNode

Parameters:

tuple - the input storm tuple.