logging - Spring-Boot 日志记录到 Kafka : how to eliminate warning; best practices

Question

我被问到如何从作为 Oozie 的 Java 操作运行的 Spring Boot 应用程序捕获日志记录输出。

我最初的想法是可以编辑一些 log4j 属性来捕获 YARN 或 Oozie 中的应用程序日志。然后我突然想到，对于在各种集群节点上运行的特定应用程序，Kafka 将是一种更容易捕获和聚合日志消息的方法。通过订阅主题来监视分布式系统比通过日志文件钓鱼要容易得多。

我注意到 Kafka 有一个 log4j appender，所以我尝试创建一个最小的可重现示例(发布在 github 上:https://github.com/alexwoolford/spring-boot-log-to-kafka-example)。这是来自 pom.xml 的片段:

<parent>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-parent</artifactId>
    <version>1.4.4.RELEASE</version>
</parent>

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
        <exclusions>
            <exclusion>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-logging</artifactId>
            </exclusion>
            <exclusion>
                <groupId>org.springframework.boot</groupId>
                <artifactId>logback-classic</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-log4j</artifactId>
    </dependency>
    <dependency>
        <groupId>org.apache.kafka</groupId>
        <artifactId>kafka-log4j-appender</artifactId>
        <version>0.10.0.0</version>
    </dependency>
    <dependency>
        <groupId>net.logstash.log4j</groupId>
        <artifactId>jsonevent-layout</artifactId>
        <version>1.7</version>
    </dependency>
    <dependency>
        <groupId>commons-logging</groupId>
        <artifactId>commons-logging</artifactId>
        <version>1.2</version>
    </dependency>
</dependencies>

我的 log4j.properties 文件如下所示:

log4j.rootLogger=INFO
log4j.appender.KAFKA=org.apache.kafka.log4jappender.KafkaLog4jAppender
log4j.appender.KAFKA.layout=net.logstash.log4j.JSONEventLayoutV1
log4j.appender.KAFKA.topic=logs
log4j.appender.KAFKA.brokerList=hdp-single-node:6667
log4j.appender.KAFKA.syncSend=true
log4j.appender.KAFKA.producer.type=async
log4j.logger.io.woolford=INFO, KAFKA

这有效，只是它会生成警告:

log4j:WARN No appenders could be found for logger (org.apache.kafka.clients.producer.ProducerConfig).
log4j:WARN Please initialize the log4j system properly.
log4j:WARN See http://logging.apache.org/log4j/1.2/faq.html#noconfig for more info.

尽管此应用程序运行并执行我需要的操作，但警告表明我配置错误。你能看出需要改变什么吗？

另外，我注意到 Spring Boot 默认使用 Logback我注意到有一个开源项目， logback-kafka-appender ，这允许 Logback 附加到 Kafka。 Kafka log4j appender 是 Spring Boot 登录到 Kafka 的最佳方式吗？

Answer 1

Log4j2 有一个 Kafka appender .有必要添加 spring-boot-starter-log4j2和 jackson-databind文物到 pom.xml :

<dependencies>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter</artifactId>
        <exclusions>
            <exclusion>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-starter-logging</artifactId>
            </exclusion>
            <exclusion>
                <groupId>org.springframework.boot</groupId>
                <artifactId>logback-classic</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-log4j2</artifactId>
    </dependency>
    <dependency>
        <groupId>org.apache.kafka</groupId>
        <artifactId>kafka-log4j-appender</artifactId>
        <version>0.10.0.0</version>
        <exclusions>
            <exclusion>
                <groupId>org.slf4j</groupId>
                <artifactId>slf4j-log4j12</artifactId>
            </exclusion>
        </exclusions>
    </dependency>
    <dependency>
        <groupId>com.fasterxml.jackson.core</groupId>
        <artifactId>jackson-databind</artifactId>
        <version>2.8.6</version>
    </dependency>
</dependencies>

然后我创建了一个 XML 格式 log4j2.xml文件:

<?xml version="1.0" encoding="UTF-8"?>
<Configuration status="info" name="spring-boot-log-to-kafka-example" packages="io.woolford">
    <Appenders>
        <Kafka name="kafkaAppender" topic="logs">
            <JSONLayout />
            <Property name="bootstrap.servers">hdp-single-node:6667</Property>
        </Kafka>
    </Appenders>
    <Loggers>
        <Root level="INFO">
            <AppenderRef ref="kafkaAppender"/>
        </Root>
        <Logger name="org.apache.kafka" level="WARN" />
    </Loggers>
</Configuration>

日志消息以 JSON 格式发送到 Kafka，例如

{
    "timeMillis": 1485736022854,
    "thread": "Thread-1",
    "level": "INFO",
    "loggerName": "org.springframework.context.annotation.AnnotationConfigApplicationContext",
    "message": "Closing org.springframework.context.annotation.AnnotationConfigApplicationContext@20140db9: startup date [Sun Jan 29 17:26:52 MST 2017]; root of context hierarchy",
    "endOfBatch": false,
    "loggerFqcn": "org.apache.commons.logging.impl.SLF4JLocationAwareLog",
    "threadId": 19,
    "threadPriority": 5
}