commit | 4f7fe1c60c2e79bff7aab54cab7dd75d36e58135 | [log] [tgz] |
---|---|---|
author | Marcin Czech <maczech@gmail.com> | Fri Sep 03 21:28:54 2021 +0200 |
committer | Marcin Czech <maczech@gmail.com> | Wed Sep 08 10:49:36 2021 +0200 |
tree | 93c765bca0899a0a459a3ce4d6f105b413c953ba | |
parent | 49db3794e29c5c335f5ce19170b891f397b8318b [diff] |
Allow to collect stream events publishing metrics Add extension point which allows to bind implementation to collect metrics for success/failure of publishing stream events metrics. Also provide default implementation which does nothing. Bug: Issue 14928 Change-Id: I9bf739b0b1fdc09862b9ff276ed52c1900f2e7be
API of a generic events broker for use with Gerrit Code Review.
Enables the de-coupling between Gerrit, plugins and the different implementations of a generic events broker.
It is a quite common use case for consumers of this library to listen for Gerrit events and to stream them on a specific topic.
Since the implementation of such logic is always the same, this library provides a generic stream events publisher which will perform the relevant operations.
In order to listen and stream gerrit events, consumers of this API need to provide a binding for the StreamEventPublisherConfig
configuration and java.util.concurrent.Executor
binding annotated with StreamEventPublisherExecutor
annotation. A default single threaded implementation (StreamEventPublisherExecutor
) is provided by the library. The last step is to explicitly bind the Stream Events Publisher, as such:
import com.gerritforge.gerrit.eventbroker.publisher.StreamEventPublisher; import com.google.gerrit.extensions.registration.DynamicSet; import com.google.gerrit.server.events.EventListener; import com.google.inject.AbstractModule; public class SomeModule extends AbstractModule { @Override protected void configure() { long messagePublishingTimeout = 1000L; bind(StreamEventPublisherConfig.class) .toInstance(new StreamEventPublisherConfig( "name_of_the_stream_events_topic", messagePublishingTimeout)); bind(Executor.class).annotatedWith(StreamEventPublisherExecutor.class).toProvider(StreamEventPublisherExecutorProvider.class); DynamicSet.bind(binder(), EventListener.class).to(StreamEventPublisher.class); } }
Alternative way to setup Stream Event Publisher is to use default Guice module:
import com.gerritforge.gerrit.eventbroker.publisher.StreamEventPublisherModule; import com.google.inject.AbstractModule; import com.google.inject.TypeLiteral; import com.google.inject.name.Names; public class SomeModule extends AbstractModule { @Override protected void configure() { long messagePublishingTimeout = 1000L; bind(StreamEventPublisherConfig.class) .toInstance(new StreamEventPublisherConfig( "name_of_the_stream_events_topic", messagePublishingTimeout)); install(new StreamEventPublisherModule()); } }
Note: To avoid message duplication Stream Events Publisher uses gerrit.instanceId and Event.instanceId to filter out forwarded events.
When StreamEventPublisher
is used user can optionally bind an implementation of the BrokerMetrics` interface. This will allow to collect metrics about successful/failure stream events publishing. If no binding is provided default implementation will skip collecting metrics:
import com.google.gerrit.extensions.registration.DynamicItem; import com.google.inject.AbstractModule; public class SomeModule extends AbstractModule { @Override protected void configure() { DynamicItem.bind(binder(), BrokerMetrics.class) .to(BrokerMetricsImpl.class) .in(Scopes.SINGLETON); } }
Note: BrokerMetrics
implementation must be bound in a plugin module.