本篇文章给大家分享的是有关SpringCloud中如何进行日志收集Kafka-ELK，小编觉得挺实用的，因此分享给大家学习，希望大家阅读完这篇文章后可以有所收获，话不多说，跟着小编一起来看看吧。
微服务应用在容器化后，日志的查询就会变成困难的问题，虽说有portainer这类的容器管理工具，能够方便的查询每个容器中的日志，但容器到达一定数量后，尤其是应用有多个实例时候，查询就成了头疼的问题。所以我们采用了Kafka-Logstash-Elasticsearch-Kibana的方案来处理日志。
首先说说我的日志收集思路：
应用将日志传入kafka集群。在集群建立相应topic，并传入日志。
logstash在kafka上消费（读取）日志内容，写入elasticsearch。
kibana读elasticsearch，做对应的展示。
这样的好处，1）几乎不用做特别大的修改，只需做一定的配置工作即可完成日志收集；2）日志内容输入kafka几乎没有什么瓶颈，另外kafka的扩展性能很好，也很简单；3）收集的日志几乎是实时的；4）整体的扩展性很好，很容易消除瓶颈，例如elasticsearch分片、扩展都很容易。
应用侧配置
在应用中，我们只需配置log4j的相应配置，将其日志输出到kafka即可。以下为配置示例，配置中包含将日志输入出命令行和kafka部分中。注意，在输出到kafka中，需要有一个appender类kafka.producer.KafkaLog4jAppender一般是没有的，则我在本地自己写上该类（KafkaLog4jAppender.java），并加入相应的文件路径。
log4j.rootLogger=INFO,console,kafka# 输出到kafkalog4j.appender.kafka=com.yang.config.KafkaLog4jAppender #kafka.producer.KafkaLog4jAppenderlog4j.appender.kafka.topic=api-adminlog4j.appender.kafka.brokerList=192.0.0.2:9092,192.0.0.3:9092,192.0.0.4:9092 # 这里填写kafka的iplog4j.appender.kafka.compressionType=nonelog4j.appender.kafka.syncSend=truelog4j.appender.kafka.layout=org.apache.log4j.PatternLayoutlog4j.appender.kafka.layout.ConversionPattern=%d{yyyy-MM-dd HH:mm:ss} %-5p %c{1}:%L %% - %m%n# 输出到Consolelog4j.appender.console=org.apache.log4j.ConsoleAppenderlog4j.appender.console.target=System.errlog4j.appender.console.layout=org.apache.log4j.PatternLayoutlog4j.appender.console.layout.ConversionPattern=%d (%t) [%p - %l] %m%nKafkaLog4jAppender.java
public class KafkaLog4jAppender extends AppenderSkeleton { private static final String BOOTSTRAP_SERVERS_CONFIG = ProducerConfig.BOOTSTRAP_SERVERS_CONFIG; private static final String COMPRESSION_TYPE_CONFIG = ProducerConfig.COMPRESSION_TYPE_CONFIG; private static final String ACKS_CONFIG = ProducerConfig.ACKS_CONFIG; private static final String RETRIES_CONFIG = ProducerConfig.RETRIES_CONFIG; private static final String KEY_SERIALIZER_CLASS_CONFIG = ProducerConfig.KEY_SERIALIZER_CLASS_CONFIG; private static final String VALUE_SERIALIZER_CLASS_CONFIG = ProducerConfig.VALUE_SERIALIZER_CLASS_CONFIG; private static final String SECURITY_PROTOCOL = CommonClientConfigs.SECURITY_PROTOCOL_CONFIG; private static final String SSL_TRUSTSTORE_LOCATION = SslConfigs.SSL_TRUSTSTORE_LOCATION_CONFIG; private static final String SSL_TRUSTSTORE_PASSWORD = SslConfigs.SSL_TRUSTSTORE_PASSWORD_CONFIG; private static final String SSL_KEYSTORE_TYPE = SslConfigs.SSL_KEYSTORE_TYPE_CONFIG; private static final String SSL_KEYSTORE_LOCATION = SslConfigs.SSL_KEYSTORE_LOCATION_CONFIG; private static final String SSL_KEYSTORE_PASSWORD = SslConfigs.SSL_KEYSTORE_PASSWORD_CONFIG; private String brokerList = null; private String topic = null; private String compressionType = null; private String securityProtocol = null; private String sslTruststoreLocation = null; private String sslTruststorePassword = null; private String sslKeystoreType = null; private String sslKeystoreLocation = null; private String sslKeystorePassword = null; private int retries = 0; private int requiredNumAcks = Integer.MAX_VALUE; private boolean syncSend = false; private Producer<byte[], byte[]> producer = null; public Producer<byte[], byte[]> getProducer() { return producer; } public String getBrokerList() { return brokerList; } public void setBrokerList(String brokerList) { this.brokerList = brokerList; } public int getRequiredNumAcks() { return requiredNumAcks; } public void setRequiredNumAcks(int requiredNumAcks) { this.requiredNumAcks = requiredNumAcks; } public int getRetries() { return retries; } public void setRetries(int retries) { this.retries = retries; } public String getCompressionType() { return compressionType; } public void setCompressionType(String compressionType) { this.compressionType = compressionType; } public String getTopic() { return topic; } public void setTopic(String topic) { this.topic = topic; } public boolean getSyncSend() { return syncSend; } public void setSyncSend(boolean syncSend) { this.syncSend = syncSend; } public String getSslTruststorePassword() { return sslTruststorePassword; } public String getSslTruststoreLocation() { return sslTruststoreLocation; } public String getSecurityProtocol() { return securityProtocol; } public void setSecurityProtocol(String securityProtocol) { this.securityProtocol = securityProtocol; } public void setSslTruststoreLocation(String sslTruststoreLocation) { this.sslTruststoreLocation = sslTruststoreLocation; } public void setSslTruststorePassword(String sslTruststorePassword) { this.sslTruststorePassword = sslTruststorePassword; } public void setSslKeystorePassword(String sslKeystorePassword) { this.sslKeystorePassword = sslKeystorePassword; } public void setSslKeystoreType(String sslKeystoreType) { this.sslKeystoreType = sslKeystoreType; } public void setSslKeystoreLocation(String sslKeystoreLocation) { this.sslKeystoreLocation = sslKeystoreLocation; } public String getSslKeystoreLocation() { return sslKeystoreLocation; } public String getSslKeystoreType() { return sslKeystoreType; } public String getSslKeystorePassword() { return sslKeystorePassword; } @Override public void activateOptions() { // check for config parameter validity Properties props = new Properties(); if (brokerList != null) props.put(BOOTSTRAP_SERVERS_CONFIG, brokerList); if (props.isEmpty()) throw new ConfigException("The bootstrap servers property should be specified"); if (topic == null) throw new ConfigException("Topic must be specified by the Kafka log4j appender"); if (compressionType != null) props.put(COMPRESSION_TYPE_CONFIG, compressionType); if (requiredNumAcks != Integer.MAX_VALUE) props.put(ACKS_CONFIG, Integer.toString(requiredNumAcks)); if (retries > 0) props.put(RETRIES_CONFIG, retries); if (securityProtocol != null && sslTruststoreLocation != null && sslTruststorePassword != null) { props.put(SECURITY_PROTOCOL, securityProtocol); props.put(SSL_TRUSTSTORE_LOCATION, sslTruststoreLocation); props.put(SSL_TRUSTSTORE_PASSWORD, sslTruststorePassword); if (sslKeystoreType != null && sslKeystoreLocation != null && sslKeystorePassword != null) { props.put(SSL_KEYSTORE_TYPE, sslKeystoreType); props.put(SSL_KEYSTORE_LOCATION, sslKeystoreLocation); props.put(SSL_KEYSTORE_PASSWORD, sslKeystorePassword); } } props.put(KEY_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.ByteArraySerializer"); props.put(VALUE_SERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.ByteArraySerializer"); this.producer = getKafkaProducer(props); LogLog.debug("Kafka producer connected to " + brokerList); LogLog.debug("Logging for topic: " + topic); } protected Producer<byte[], byte[]> getKafkaProducer(Properties props) { return new KafkaProducer<byte[], byte[]>(props); } @Override protected void append(LoggingEvent event) { String message = subAppend(event); LogLog.debug("[" + new Date(event.getTimeStamp()) + "]" + message); Future<RecordMetadata> response = producer.send(new ProducerRecord<byte[], byte[]>(topic, message.getBytes())); if (syncSend) { try { response.get(); } catch (InterruptedException ex) { throw new RuntimeException(ex); } catch (ExecutionException ex) { throw new RuntimeException(ex); } } } private String subAppend(LoggingEvent event) { return (this.layout == null) ? event.getRenderedMessage() : this.layout.format(event); } public void close() { if (!this.closed) { this.closed = true; producer.close(); } } public boolean requiresLayout() { return true; }}logstash配置
logstash可能会有快速启动实例的需求，我们就采用docker部署，能够快速启动、扩展等功能。
镜像就直接logstash官方镜像logstash docker镜像，我们选择了一种最简单启动方式做演示，具体还有多种docker部署方法，可以参考以上链接。
docker启动命令，input输入中，指定kafka集群地址和对应topic；输出，则是elasticsearch集群地址、索引，以及elastisearch配置参数。
#启动命令docker run -it -d logstash -e 'input { kafka { bootstrap_servers => "kafkaIp1:9092,kafkaIp2:9092" topics => ["api-admin"] } } output { elasticsearch { hosts => ["elasticsearch2:9200","elasticsearch3:9200","elasticsearch4:9200"] index => "api-admin-%{+YYYY.MM.dd}" flush_size => 20000 idle_flush_time => 10 template_overwrite => true } }'在marathon中启动在Command选项中加入参数logstash -e 'input {} output {}'即可。另外说一句， 如果在容器编排系统（mesos/marathon、kubernetes）中，可能会有健康检查要求，其端口为9600。
以上就是SpringCloud中如何进行日志收集Kafka-ELK，小编相信有部分知识点可能是我们日常工作会见到或用到的。希望你能通过这篇文章学到更多知识。更多详情敬请关注编程网行业资讯频道。
