Made changes as per comments.
kafkaProducer is now non-static.
TODO: KafkaPublisherManager Service and not Singleton.
Kafka event publishing.
Change-Id: I5ec20a6e4950c38e822468d343521ab77475b7d3
diff --git a/apps/kafka-integration/core/src/main/java/org/onosproject/kafkaintegration/kafka/EventMonitor.java b/apps/kafka-integration/core/src/main/java/org/onosproject/kafkaintegration/kafka/EventMonitor.java
new file mode 100644
index 0000000..6e7291b
--- /dev/null
+++ b/apps/kafka-integration/core/src/main/java/org/onosproject/kafkaintegration/kafka/EventMonitor.java
@@ -0,0 +1,242 @@
+/**
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.kafkaintegration.kafka;
+
+import org.apache.felix.scr.annotations.Activate;
+import org.apache.felix.scr.annotations.Component;
+import org.apache.felix.scr.annotations.Deactivate;
+import org.apache.felix.scr.annotations.Modified;
+import org.apache.felix.scr.annotations.Property;
+import org.apache.felix.scr.annotations.Reference;
+import org.apache.felix.scr.annotations.ReferenceCardinality;
+import org.apache.kafka.clients.producer.ProducerRecord;
+import org.onosproject.cfg.ComponentConfigService;
+import org.onosproject.kafkaintegration.api.EventConversionService;
+import org.onosproject.kafkaintegration.api.EventSubscriptionService;
+import org.onosproject.net.device.DeviceEvent;
+import org.onosproject.net.device.DeviceListener;
+import org.onosproject.net.device.DeviceService;
+import org.onosproject.net.link.LinkEvent;
+import org.onosproject.net.link.LinkListener;
+import org.onosproject.net.link.LinkService;
+import org.osgi.service.component.ComponentContext;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.Dictionary;
+import java.util.UUID;
+import java.util.concurrent.ExecutionException;
+import java.util.concurrent.ExecutorService;
+
+import static com.google.common.base.Strings.isNullOrEmpty;
+import static java.util.concurrent.Executors.newSingleThreadScheduledExecutor;
+import static org.onlab.util.Tools.get;
+import static org.onlab.util.Tools.groupedThreads;
+import static org.onosproject.kafkaintegration.api.dto.OnosEvent.Type.DEVICE;
+import static org.onosproject.kafkaintegration.api.dto.OnosEvent.Type.LINK;
+
+/**
+ * Encapsulates the behavior of monitoring various ONOS events.
+ * */
+@Component(immediate = true)
+public class EventMonitor {
+ private final Logger log = LoggerFactory.getLogger(getClass());
+
+ @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+ protected EventSubscriptionService eventSubscriptionService;
+
+ @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+ protected EventConversionService eventConversionService;
+
+ @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+ protected DeviceService deviceService;
+
+ @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+ protected LinkService linkService;
+
+ @Reference(cardinality = ReferenceCardinality.MANDATORY_UNARY)
+ protected ComponentConfigService componentConfigService;
+
+ private final DeviceListener deviceListener = new InternalDeviceListener();
+ private final LinkListener linkListener = new InternalLinkListener();
+
+ protected ExecutorService eventExecutor;
+
+ private static final String BOOTSTRAP_SERVERS = "localhost:9092";
+ private static final int RETRIES = 1;
+ private static final int MAX_IN_FLIGHT_REQUESTS_PER_CONNECTION = 5;
+ private static final int REQUEST_REQUIRED_ACKS = 1;
+ private static final String KEY_SERIALIZER = "org.apache.kafka.common.serialization.StringSerializer";
+ private static final String VALUE_SERIALIZER = "org.apache.kafka.common.serialization.ByteArraySerializer";
+
+ @Property(name = "bootstrap.servers", value = BOOTSTRAP_SERVERS,
+ label = "Default host/post pair to establish initial connection to Kafka cluster.")
+ private String bootstrapServers = BOOTSTRAP_SERVERS;
+
+ @Property(name = "retries", intValue = RETRIES,
+ label = "Number of times the producer can retry to send after first failure")
+ private int retries = RETRIES;
+
+ @Property(name = "max.in.flight.requests.per.connection", intValue = MAX_IN_FLIGHT_REQUESTS_PER_CONNECTION,
+ label = "The maximum number of unacknowledged requests the client will send before blocking")
+ private int maxInFlightRequestsPerConnection = MAX_IN_FLIGHT_REQUESTS_PER_CONNECTION;
+
+ @Property(name = "request.required.acks", intValue = 1,
+ label = "Producer will get an acknowledgement after the leader has replicated the data")
+ private int requestRequiredAcks = REQUEST_REQUIRED_ACKS;
+
+ @Property(name = "key.serializer", value = KEY_SERIALIZER,
+ label = "Serializer class for key that implements the Serializer interface.")
+ private String keySerializer = KEY_SERIALIZER;
+
+ @Property(name = "value.serializer", value = VALUE_SERIALIZER,
+ label = "Serializer class for value that implements the Serializer interface.")
+ private String valueSerializer = VALUE_SERIALIZER;
+
+ private Producer producer;
+
+ @Activate
+ protected void activate(ComponentContext context) {
+ componentConfigService.registerProperties(getClass());
+ eventExecutor = newSingleThreadScheduledExecutor(groupedThreads("onos/onosEvents", "events-%d", log));
+ deviceService.addListener(deviceListener);
+ linkService.addListener(linkListener);
+ producer = new Producer(bootstrapServers, retries, maxInFlightRequestsPerConnection,
+ requestRequiredAcks, keySerializer, valueSerializer);
+ producer.start();
+
+ log.info("Started");
+ }
+
+ @Deactivate
+ protected void deactivate() {
+ componentConfigService.unregisterProperties(getClass(), false);
+ deviceService.removeListener(deviceListener);
+ linkService.removeListener(linkListener);
+ producer.stop();
+ eventExecutor.shutdownNow();
+ eventExecutor = null;
+
+ log.info("Stopped");
+ }
+
+ @Modified
+ private void modified(ComponentContext context) {
+ if (context == null) {
+ bootstrapServers = BOOTSTRAP_SERVERS;
+ retries = RETRIES;
+ maxInFlightRequestsPerConnection = MAX_IN_FLIGHT_REQUESTS_PER_CONNECTION;
+ requestRequiredAcks = REQUEST_REQUIRED_ACKS;
+ keySerializer = KEY_SERIALIZER;
+ valueSerializer = VALUE_SERIALIZER;
+ return;
+ }
+ Dictionary properties = context.getProperties();
+
+ String newBootstrapServers = BOOTSTRAP_SERVERS;
+ int newRetries = RETRIES;
+ int newMaxInFlightRequestsPerConnection = MAX_IN_FLIGHT_REQUESTS_PER_CONNECTION;
+ int newRequestRequiredAcks = REQUEST_REQUIRED_ACKS;
+ try {
+ String s = get(properties, "bootstrapServers");
+ newBootstrapServers = isNullOrEmpty(s)
+ ? bootstrapServers : s.trim();
+
+ s = get(properties, "retries");
+ newRetries = isNullOrEmpty(s)
+ ? retries : Integer.parseInt(s.trim());
+
+ s = get(properties, "maxInFlightRequestsPerConnection");
+ newMaxInFlightRequestsPerConnection = isNullOrEmpty(s)
+ ? maxInFlightRequestsPerConnection : Integer.parseInt(s.trim());
+
+ s = get(properties, "requestRequiredAcks");
+ newRequestRequiredAcks = isNullOrEmpty(s)
+ ? requestRequiredAcks : Integer.parseInt(s.trim());
+
+ } catch (NumberFormatException | ClassCastException e) {
+ return;
+ }
+
+ boolean modified = newBootstrapServers != bootstrapServers ||
+ newRetries != retries ||
+ newMaxInFlightRequestsPerConnection != maxInFlightRequestsPerConnection ||
+ newRequestRequiredAcks != requestRequiredAcks;
+
+ if (modified) {
+ bootstrapServers = newBootstrapServers;
+ retries = newRetries;
+ maxInFlightRequestsPerConnection = newMaxInFlightRequestsPerConnection;
+ requestRequiredAcks = newRequestRequiredAcks;
+ if (producer != null) {
+ producer.stop();
+ }
+ producer = new Producer(bootstrapServers, retries, maxInFlightRequestsPerConnection,
+ requestRequiredAcks, keySerializer, valueSerializer);
+ producer.start();
+ log.info("Modified");
+ } else {
+ return;
+ }
+ }
+
+ private class InternalDeviceListener implements DeviceListener {
+
+ @Override
+ public void event(DeviceEvent event) {
+ if (!eventSubscriptionService.getEventSubscribers(DEVICE).isEmpty()) {
+ eventExecutor.execute(() -> {
+ try {
+ String id = UUID.randomUUID().toString();
+ producer.send(new ProducerRecord<>(DEVICE.toString(),
+ id, event.subject().toString().getBytes())).get();
+ log.debug("Device event sent successfully.");
+ } catch (InterruptedException e) {
+ Thread.currentThread().interrupt();
+ } catch (ExecutionException e) {
+ log.error("Exception thrown {}", e);
+ }
+ });
+ } else {
+ log.debug("No device listeners");
+ }
+ }
+ }
+
+ private class InternalLinkListener implements LinkListener {
+
+ @Override
+ public void event(LinkEvent event) {
+ if (!eventSubscriptionService.getEventSubscribers(LINK).isEmpty()) {
+ eventExecutor.execute(() -> {
+ try {
+ String id = UUID.randomUUID().toString();
+ producer.send(new ProducerRecord<>(LINK.toString(),
+ id, event.subject().toString().getBytes())).get();
+ log.debug("Link event sent successfully.");
+ } catch (InterruptedException e) {
+ Thread.currentThread().interrupt();
+ } catch (ExecutionException e) {
+ log.error("Exception thrown {}", e);
+ }
+ });
+ } else {
+ log.debug("No link listeners");
+ }
+ }
+ }
+}