Package io.fluxcapacitor.javaclient.tracking.client

Class DefaultTracker

java.lang.Object

io.fluxcapacitor.javaclient.tracking.client.DefaultTracker

All Implemented Interfaces:

Registration, Runnable

public class DefaultTracker
extends Object
implements Runnable, Registration

A tracker keeps reading messages until it is stopped (generally only when the application is shut down).

A tracker is always running in a single thread. To balance the processing load over multiple threads create multiple trackers with the same name but different tracker id.

Trackers with different names will receive the same messages. Trackers with the same name will not. (Flux Capacitor will load balance between trackers with the same name).

Tracking stops if the provided message consumer throws an exception while handling messages (i.e. the tracker will need to be manually restarted in that case). However, if the tracker encounters an exception while fetching messages it will retry fetching indefinitely until this succeeds.

Trackers can choose a desired maximum batch size for consuming. By default this batch size will be the same as the batch size the tracker uses to fetch messages from Flux Capacitor. Each time the consumer has finished consuming a batch the tracker will update its position with Flux Capacitor.

Trackers can be configured to use batch interceptors. A batch interceptor manages the invocation of the message consumer. It is therefore typically used to manage a database transaction around the invocation of the consumer. Note that if the interceptor gives rise to an exception the tracker will be stopped.

Method Summary

Modifier and Type	Method	Description
void	cancel()
protected MessageBatch	fetch(Long lastIndex)
protected void	process(MessageBatch batch)
void	run()
static Registration	start(Consumer<List<SerializedMessage>> consumer, ConsumerConfiguration config, Client client)	Starts one or more trackers.
static Registration	start(Consumer<List<SerializedMessage>> consumer, ConsumerConfiguration config, TrackingClient trackingClient)

Methods inherited from class java.lang.Object

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

Methods inherited from interface io.fluxcapacitor.common.Registration

merge

Method Details

start

public static Registration start(Consumer<List<SerializedMessage>> consumer,
 ConsumerConfiguration config,
 Client client)

Starts one or more trackers. Messages will be passed to the given consumer. Once the consumer is done the position of the tracker is automatically updated.

Each tracker started is using a single thread. To track in parallel configure the number of trackers using ConsumerConfiguration.

start

public static Registration start(Consumer<List<SerializedMessage>> consumer,
 ConsumerConfiguration config,
 TrackingClient trackingClient)

run

public void run()

Specified by:

run in interface Runnable

fetch

protected MessageBatch fetch(Long lastIndex)

process

protected void process(MessageBatch batch)

cancel

public void cancel()

Specified by:

cancel in interface Registration