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()	Cancels the resource or subscription associated with this registration.
protected void	cancelAndDisconnect()
protected MessageBatch	fetch(Long lastIndex)
protected void	pauseFetchIfNeeded()
protected void	process(MessageBatch batch)
void	run()
static Registration	start(Consumer<List<SerializedMessage>> consumer, MessageType messageType, ConsumerConfiguration config, Client client)	Starts one or more trackers.
static Registration	start(Consumer<List<SerializedMessage>> consumer, MessageType messageType, ConsumerConfiguration config, FluxCapacitor fluxCapacitor)	Starts one or more trackers.
static Registration	start(Consumer<List<SerializedMessage>> consumer, MessageType messageType, String topic, ConsumerConfiguration config, Client client)	Starts one or more trackers.
static Registration	start(Consumer<List<SerializedMessage>> consumer, MessageType messageType, String topic, ConsumerConfiguration config, FluxCapacitor fluxCapacitor)	Starts one or more trackers.
static Registration	start(Consumer<List<SerializedMessage>> consumer, ConsumerConfiguration config, TrackingClient trackingClient)	Starts one or more trackers that consume messages using the provided trackingClient and process them using the provided consumer.

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,
 MessageType messageType,
 ConsumerConfiguration config,
 FluxCapacitor fluxCapacitor)

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.

FluxCapacitorInterceptor will be added to the list of batch interceptors in the given configuration. This ensures that a thread local FluxCapacitor instance will always be available during tracking.

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,
 MessageType messageType,
 String topic,
 ConsumerConfiguration config,
 FluxCapacitor fluxCapacitor)

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.

FluxCapacitorInterceptor will be added to the list of batch interceptors in the given configuration. This ensures that a thread local FluxCapacitor instance will always be available during tracking.

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,
 MessageType messageType,
 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,
 MessageType messageType,
 @Nullable
 String topic,
 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)

Starts one or more trackers that consume messages using the provided trackingClient and process them using the provided consumer. Each tracker operates in its own thread, and their positions are managed automatically upon processing the messages.

run

public void run()

Specified by:

run in interface Runnable

pauseFetchIfNeeded

protected void pauseFetchIfNeeded()

fetch

protected MessageBatch fetch(Long lastIndex)

process

protected void process(MessageBatch batch)

cancelAndDisconnect

protected void cancelAndDisconnect()

cancel

public void cancel()

Description copied from interface: Registration

Cancels the resource or subscription associated with this registration.

Calling this method should be idempotent and safe to invoke multiple times.

Specified by:

cancel in interface Registration