2 * ============LICENSE_START=======================================================
3 * Copyright (C) 2016-2018 Ericsson. All rights reserved.
4 * ================================================================================
5 * Licensed under the Apache License, Version 2.0 (the "License");
6 * you may not use this file except in compliance with the License.
7 * You may obtain a copy of the License at
9 * http://www.apache.org/licenses/LICENSE-2.0
11 * Unless required by applicable law or agreed to in writing, software
12 * distributed under the License is distributed on an "AS IS" BASIS,
13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 * See the License for the specific language governing permissions and
15 * limitations under the License.
17 * SPDX-License-Identifier: Apache-2.0
18 * ============LICENSE_END=========================================================
21 package org.onap.policy.apex.plugins.event.carrier.kafka;
23 import java.util.EnumMap;
26 import org.apache.kafka.clients.consumer.ConsumerRecord;
27 import org.apache.kafka.clients.consumer.ConsumerRecords;
28 import org.apache.kafka.clients.consumer.KafkaConsumer;
29 import org.onap.policy.apex.core.infrastructure.threading.ApplicationThreadFactory;
30 import org.onap.policy.apex.core.infrastructure.threading.ThreadUtilities;
31 import org.onap.policy.apex.service.engine.event.ApexEventConsumer;
32 import org.onap.policy.apex.service.engine.event.ApexEventException;
33 import org.onap.policy.apex.service.engine.event.ApexEventReceiver;
34 import org.onap.policy.apex.service.engine.event.PeeredReference;
35 import org.onap.policy.apex.service.parameters.eventhandler.EventHandlerParameters;
36 import org.onap.policy.apex.service.parameters.eventhandler.EventHandlerPeeredMode;
37 import org.slf4j.Logger;
38 import org.slf4j.LoggerFactory;
41 * This class implements an Apex event consumer that receives events using Kafka.
43 * @author Liam Fallon (liam.fallon@ericsson.com)
45 public class ApexKafkaConsumer implements ApexEventConsumer, Runnable {
46 // Get a reference to the logger
47 private static final Logger LOGGER = LoggerFactory.getLogger(ApexKafkaConsumer.class);
49 // The Kafka parameters read from the parameter service
50 private KafkaCarrierTechnologyParameters kafkaConsumerProperties;
52 // The event receiver that will receive events from this consumer
53 private ApexEventReceiver eventReceiver;
55 // The Kafka consumer used to receive events using Kafka
56 private KafkaConsumer<String, String> kafkaConsumer;
58 // The name for this consumer
59 private String name = null;
61 // The peer references for this event handler
62 private Map<EventHandlerPeeredMode, PeeredReference> peerReferenceMap = new EnumMap<>(EventHandlerPeeredMode.class);
64 // The consumer thread and stopping flag
65 private Thread consumerThread;
66 private boolean stopOrderedFlag = false;
72 public void init(final String consumerName, final EventHandlerParameters consumerParameters,
73 final ApexEventReceiver incomingEventReceiver) throws ApexEventException {
74 this.eventReceiver = incomingEventReceiver;
75 this.name = consumerName;
77 // Check and get the Kafka Properties
78 if (!(consumerParameters.getCarrierTechnologyParameters() instanceof KafkaCarrierTechnologyParameters)) {
79 LOGGER.warn("specified consumer properties of type \""
80 + consumerParameters.getCarrierTechnologyParameters().getClass().getCanonicalName()
81 + "\" are not applicable to a Kafka consumer");
82 throw new ApexEventException("specified consumer properties of type \""
83 + consumerParameters.getCarrierTechnologyParameters().getClass().getCanonicalName()
84 + "\" are not applicable to a Kafka consumer");
86 kafkaConsumerProperties =
87 (KafkaCarrierTechnologyParameters) consumerParameters.getCarrierTechnologyParameters();
89 // Kick off the Kafka consumer
90 kafkaConsumer = new KafkaConsumer<>(kafkaConsumerProperties.getKafkaConsumerProperties());
91 kafkaConsumer.subscribe(kafkaConsumerProperties.getConsumerTopicListAsCollection());
92 if (LOGGER.isDebugEnabled()) {
93 LOGGER.debug("event receiver for " + this.getClass().getName() + ":" + this.name + " subscribed to topics: "
94 + kafkaConsumerProperties.getConsumerTopicList());
102 public void start() {
103 // Configure and start the event reception thread
104 final String threadName = this.getClass().getName() + ":" + this.name;
105 consumerThread = new ApplicationThreadFactory(threadName).newThread(this);
106 consumerThread.setDaemon(true);
107 consumerThread.start();
114 public String getName() {
122 public PeeredReference getPeeredReference(final EventHandlerPeeredMode peeredMode) {
123 return peerReferenceMap.get(peeredMode);
130 public void setPeeredReference(final EventHandlerPeeredMode peeredMode, final PeeredReference peeredReference) {
131 peerReferenceMap.put(peeredMode, peeredReference);
139 // Kick off the Kafka consumer
140 kafkaConsumer = new KafkaConsumer<>(kafkaConsumerProperties.getKafkaConsumerProperties());
141 kafkaConsumer.subscribe(kafkaConsumerProperties.getConsumerTopicListAsCollection());
142 if (LOGGER.isDebugEnabled()) {
143 LOGGER.debug("event receiver for " + this.getClass().getName() + ":" + this.name + " subscribed to topics: "
144 + kafkaConsumerProperties.getConsumerTopicList());
147 // The endless loop that receives events over Kafka
148 while (consumerThread.isAlive() && !stopOrderedFlag) {
150 final ConsumerRecords<String, String> records =
151 kafkaConsumer.poll(kafkaConsumerProperties.getConsumerPollDuration().toMillis());
152 for (final ConsumerRecord<String, String> record : records) {
153 traceIfTraceEnabled(record);
154 eventReceiver.receiveEvent(null, record.value());
156 } catch (final Exception e) {
157 LOGGER.warn("error receiving events on thread {}", consumerThread.getName(), e);
161 if (!consumerThread.isInterrupted()) {
162 kafkaConsumer.close();
167 * Trace a record if trace is enabled.
169 * @param record the record to trace
171 private void traceIfTraceEnabled(final ConsumerRecord<String, String> record) {
172 if (LOGGER.isTraceEnabled()) {
173 LOGGER.trace("event received for {} for forwarding to Apex engine : {} {}",
174 this.getClass().getName() + ":" + this.name, record.key(), record.value());
183 stopOrderedFlag = true;
185 while (consumerThread.isAlive()) {
186 ThreadUtilities.sleep(kafkaConsumerProperties.getConsumerPollTime());