001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017
018package org.apache.logging.log4j.core.appender.mom.kafka;
019
020import java.nio.charset.StandardCharsets;
021import java.util.Objects;
022import java.util.Properties;
023import java.util.concurrent.ExecutionException;
024import java.util.concurrent.Future;
025import java.util.concurrent.TimeUnit;
026import java.util.concurrent.TimeoutException;
027
028import org.apache.kafka.clients.producer.Callback;
029import org.apache.kafka.clients.producer.Producer;
030import org.apache.kafka.clients.producer.ProducerRecord;
031import org.apache.kafka.clients.producer.RecordMetadata;
032import org.apache.logging.log4j.core.LoggerContext;
033import org.apache.logging.log4j.core.appender.AbstractManager;
034import org.apache.logging.log4j.core.appender.ManagerFactory;
035import org.apache.logging.log4j.core.config.Property;
036import org.apache.logging.log4j.core.util.Log4jThread;
037
038public class KafkaManager extends AbstractManager {
039
040    public static final String DEFAULT_TIMEOUT_MILLIS = "30000";
041
042    /**
043     * package-private access for testing.
044     */
045    static KafkaProducerFactory producerFactory = new DefaultKafkaProducerFactory();
046
047    private final Properties config = new Properties();
048    private Producer<byte[], byte[]> producer;
049    private final int timeoutMillis;
050
051    private final String topic;
052    private final String key;
053    private final boolean syncSend;
054    private static final KafkaManagerFactory factory = new KafkaManagerFactory();
055
056    /*
057     * The Constructor should have been declared private as all Managers are create by the internal factory;
058     */
059    public KafkaManager(final LoggerContext loggerContext, final String name, final String topic, final boolean syncSend,
060                        final Property[] properties, final String key) {
061        super(loggerContext, name);
062        this.topic = Objects.requireNonNull(topic, "topic");
063        this.syncSend = syncSend;
064        config.setProperty("key.serializer", "org.apache.kafka.common.serialization.ByteArraySerializer");
065        config.setProperty("value.serializer", "org.apache.kafka.common.serialization.ByteArraySerializer");
066        config.setProperty("batch.size", "0");
067        for (final Property property : properties) {
068            config.setProperty(property.getName(), property.getValue());
069        }
070
071        this.key = key;
072
073        this.timeoutMillis = Integer.parseInt(config.getProperty("timeout.ms", DEFAULT_TIMEOUT_MILLIS));
074    }
075
076    @Override
077    public boolean releaseSub(final long timeout, final TimeUnit timeUnit) {
078        if (timeout > 0) {
079            closeProducer(timeout, timeUnit);
080        } else {
081            closeProducer(timeoutMillis, TimeUnit.MILLISECONDS);
082        }
083        return true;
084    }
085
086    private void closeProducer(final long timeout, final TimeUnit timeUnit) {
087        if (producer != null) {
088            // This thread is a workaround for this Kafka issue: https://issues.apache.org/jira/browse/KAFKA-1660
089           final Thread closeThread = new Log4jThread(new Runnable() {
090                @Override
091                public void run() {
092                    if (producer != null) {
093                        producer.close();
094                    }
095                }
096            }, "KafkaManager-CloseThread");
097            closeThread.setDaemon(true); // avoid blocking JVM shutdown
098            closeThread.start();
099            try {
100                closeThread.join(timeUnit.toMillis(timeout));
101            } catch (final InterruptedException ignore) {
102                Thread.currentThread().interrupt();
103                // ignore
104            }
105        }
106    }
107
108    public void send(final byte[] msg) throws ExecutionException, InterruptedException, TimeoutException {
109        if (producer != null) {
110            byte[] newKey = null;
111
112            if(key != null && key.contains("${")) {
113                newKey = getLoggerContext().getConfiguration().getStrSubstitutor().replace(key).getBytes(StandardCharsets.UTF_8);
114            } else if (key != null) {
115                newKey = key.getBytes(StandardCharsets.UTF_8);
116            }
117
118            final ProducerRecord<byte[], byte[]> newRecord = new ProducerRecord<>(topic, newKey, msg);
119            if (syncSend) {
120                final Future<RecordMetadata> response = producer.send(newRecord);
121                response.get(timeoutMillis, TimeUnit.MILLISECONDS);
122            } else {
123                producer.send(newRecord, new Callback() {
124                    @Override
125                    public void onCompletion(final RecordMetadata metadata, final Exception e) {
126                        if (e != null) {
127                            LOGGER.error("Unable to write to Kafka in appender [" + getName() + "]", e);
128                        }
129                    }
130                });
131            }
132        }
133    }
134
135    public void startup() {
136        producer = producerFactory.newKafkaProducer(config);
137    }
138
139    public String getTopic() {
140        return topic;
141    }
142
143    public static KafkaManager getManager(final LoggerContext loggerContext, final String name, final String topic,
144        final boolean syncSend, final Property[] properties, final String key) {
145        StringBuilder sb = new StringBuilder(name);
146        for (Property prop: properties) {
147            sb.append(" ").append(prop.getName()).append("=").append(prop.getValue());
148        }
149        return getManager(sb.toString(), factory, new FactoryData(loggerContext, topic, syncSend, properties, key));
150    }
151
152    private static class FactoryData {
153        private final LoggerContext loggerContext;
154        private final String topic;
155        private final boolean syncSend;
156        private final Property[] properties;
157        private final String key;
158
159        public FactoryData(final LoggerContext loggerContext, final String topic, final boolean syncSend,
160            final Property[] properties, final String key) {
161            this.loggerContext = loggerContext;
162            this.topic = topic;
163            this.syncSend = syncSend;
164            this.properties = properties;
165            this.key = key;
166        }
167
168    }
169
170    private static class KafkaManagerFactory implements ManagerFactory<KafkaManager, FactoryData> {
171        @Override
172        public KafkaManager createManager(String name, FactoryData data) {
173            return new KafkaManager(data.loggerContext, name, data.topic, data.syncSend, data.properties, data.key);
174        }
175    }
176
177}