spring boot 源码解析47-Metric(RichGauge)ReaderPublicMetrics

2019年3月18日 337次阅读 来源: Spring Boot

前言

这里我们来讲解一下MetricReaderPublicMetrics,RichGaugeReaderPublicMetrics的实现,之前由于没有讲解完RichGaugeReader,MetricReader的实现,因此就没有讲解.由于现在我们基本上讲解完了前置要求(RichGaugeReader,MetricReader的实现),因此,这里就把之前漏掉没说明的进行讲解.

解析

MetricReaderPublicMetrics

  1. 字段,构造器如下:

    private final MetricReader metricReader;

public MetricReaderPublicMetrics(MetricReader metricReader) {
    Assert.notNull(metricReader, "MetricReader must not be null");
    this.metricReader = metricReader;
}

  2. 其metrics方法实现如下:

    public Collection<Metric<?>> metrics() { List<Metric<?>> result = new ArrayList<Metric<?>>(); for (Metric<?> metric : this.metricReader.findAll()) { result.add(metric); } return result; }

  3. 自动装配:

    该类的自动装配有3种情况,如图:

    《spring boot 源码解析47-Metric(RichGauge)ReaderPublicMetrics》

    1. PublicMetricsAutoConfiguration,声明如下:

      @Bean
public MetricReaderPublicMetrics metricReaderPublicMetrics() {
    // 默认情况下,this.metricReaders 等于null
    return new MetricReaderPublicMetrics(
            new CompositeMetricReader(this.metricReaders == null ? new MetricReader[0]
                    : this.metricReaders
                            .toArray(new MetricReader[this.metricReaders.size()])));
}

      1. 首先实例化CompositeMetricReader,由于默认情况下metricReaders 等于null,因此,此时传入CompositeMetricReader的是1个空数组. metricReaders声明如下:

        private final List<MetricReader> metricReaders;

public PublicMetricsAutoConfiguration(
        @ExportMetricReader ObjectProvider<List<MetricReader>> metricReaders) {
    this.metricReaders = metricReaders.getIfAvailable();
}

    2. 当我们加入了liquibase-core的依赖后,MetricsDropwizardAutoConfiguration该配置类就会生效,其中进行了如下声明:

      @Bean
public MetricReaderPublicMetrics dropwizardPublicMetrics(
        MetricRegistry metricRegistry) {
    MetricRegistryMetricReader reader = new MetricRegistryMetricReader(
            metricRegistry);
    return new MetricReaderPublicMetrics(reader);
}

      此时,MetricReaderPublicMetrics中持有的MetricReader是MetricRegistryMetricReader,因此最终会从MetricRegistry中获得数据.

      关于此处的讲解,可以参考之前的文章–>spring boot 源码解析26-Liquibase使用及LiquibaseEndpoint解析,spring boot 源码解析39-DropwizardMetricServices详解.

    3. 在加入了spring-boot-starter-integration之后,IntegrationMetricsConfiguration该配置类就会生效,如下:

      @Configuration
@ConditionalOnClass(EnableIntegrationManagement.class)
@ConditionalOnJava(JavaVersion.SEVEN)
@UsesJava7
static class IntegrationMetricsConfiguration {
    @Bean(name = IntegrationManagementConfigurer.MANAGEMENT_CONFIGURER_NAME)
    @ConditionalOnMissingBean(value = IntegrationManagementConfigurer.class, name = IntegrationManagementConfigurer.MANAGEMENT_CONFIGURER_NAME, search = SearchStrategy.CURRENT)
    public IntegrationManagementConfigurer managementConfigurer() {
        IntegrationManagementConfigurer configurer = new IntegrationManagementConfigurer();
        configurer.setDefaultCountsEnabled(true);
        configurer.setDefaultStatsEnabled(true);
        return configurer;
    }
    @Bean
    @ConditionalOnMissingBean(name = "springIntegrationPublicMetrics")
    public MetricReaderPublicMetrics springIntegrationPublicMetrics(
            IntegrationManagementConfigurer managementConfigurer) {
        return new MetricReaderPublicMetrics(
                new SpringIntegrationMetricReader(managementConfigurer));
    }
}

      IntegrationMetricsConfiguration满足如下条件时生效:

      • @ConditionalOnClass(EnableIntegrationManagement.class) –> 类路径下存在EnableIntegrationManagement.class时生效,由于加入了spring-boot-starter-integration的依赖,因此该条件生效.
      • @ConditionalOnJava(JavaVersion.SEVEN)–> 在jdk1.7及以上的环境中运行时生效.

      生效后,会注册如下2个bean:

      1. id为managementConfigurer.当满足如下条件时生效:

        • @ConditionalOnMissingBean(value = IntegrationManagementConfigurer.class, name = IntegrationManagementConfigurer.MANAGEMENT_CONFIGURER_NAME, search = SearchStrategy.CURRENT)–> 在当前applicationContext中不存在id为integrationManagementConfigurer,类型为IntegrationManagementConfigurer时生效.

      2. id为springIntegrationPublicMetrics,当满足在BeanFactory中不存在类型为MetricReaderPublicMetrics,id为springIntegrationPublicMetrics的bean时生效.因此,此时MetricReaderPublicMetrics会读取IntegrationManagementConfigurer中的数据,在上篇文章的基础上,访问http://127.0.0.1:8080/metrics,会发现返回如下内容:

        integration.channel.errorChannel.errorRate.mean: 0,
......
integration.channel.errorChannel.sendRate.count: 0,
.....
integration.channel.metricsChannel.sendRate.count: 0,
integration.channel.nullChannel.errorRate.mean: 0,
....
integration.channel.nullChannel.sendRate.count: 0,
integration.handler.org.springframework.integration.stream.CharacterStreamWritingMessageHandler#0.duration.mean: 0,
....
integration.handler.org.springframework.integration.stream.CharacterStreamWritingMessageHandler#0.activeCount: 0,
integration.handler._org.springframework.integration.errorLogger.handler.duration.mean: 0,
integration.handler._org.springframework.integration.errorLogger.handler.duration.max: 0,
integration.handler._org.springframework.integration.errorLogger.handler.duration.min: 0,
integration.handler._org.springframework.integration.errorLogger.handler.duration.stdev: 0,
integration.handler._org.springframework.integration.errorLogger.handler.duration.count: 0,
integration.handler._org.springframework.integration.errorLogger.handler.activeCount: 0,
integration.handlerCount: 2,
integration.channelCount: 3,
integration.sourceCount: 0,

        其中:

        • integration.channel.errorChannel.* 是统计errorChannel的指标,errorChannel是自动配置的
        • integration.channel.metricsChannel.*–>metricsChannel是我们自己声明的,见spring boot 源码解析42-MessageChannelMetricWriter详解.
        • integration.channel.nullChannel.* 是统计nullChannel的指标,errorChannel是自动配置的
        • integration.handler.org.springframework.integration.stream.CharacterStreamWritingMessageHandler#0 –> CharacterStreamWritingMessageHandler是我们自己声明的,见spring boot 源码解析42-MessageChannelMetricWriter详解.
        • integration.handler._org.springframework.integration.errorLogger.*–> errorLogger是自动装配的

        更多内容,请看–>spring boot 源码解析42-MessageChannelMetricWriter详解

RichGaugeReaderPublicMetrics

该类实现了PublicMetrics

  1. 字段,构造器如下:

    private final RichGaugeReader richGaugeReader;

public RichGaugeReaderPublicMetrics(RichGaugeReader richGaugeReader) {
    Assert.notNull(richGaugeReader, "RichGaugeReader must not be null");
    this.richGaugeReader = richGaugeReader;
}

  2. 其metrics实现如下:

    public Collection<Metric<?>> metrics() { List<Metric<?>> result = new ArrayList<Metric<?>>(); for (RichGauge richGauge : this.richGaugeReader.findAll()) { result.addAll(convert(richGauge)); } return result; }
    1. 从RichGaugeReader获得所有的RichGauge,进行遍历

    2. 依次调用convert方法,获得对应的Metric,加入到结果集中,代码如下:

      private List<Metric<?>> convert(RichGauge gauge) {
    List<Metric<?>> result = new ArrayList<Metric<?>>(6);
    result.add(
            new Metric<Double>(gauge.getName() + RichGauge.AVG, gauge.getAverage()));
    result.add(new Metric<Double>(gauge.getName() + RichGauge.VAL, gauge.getValue()));
    result.add(new Metric<Double>(gauge.getName() + RichGauge.MIN, gauge.getMin()));
    result.add(new Metric<Double>(gauge.getName() + RichGauge.MAX, gauge.getMax()));
    result.add(
            new Metric<Double>(gauge.getName() + RichGauge.ALPHA, gauge.getAlpha()));
    result.add(new Metric<Long>(gauge.getName() + RichGauge.COUNT, gauge.getCount()));
    return result;
}

      该方法还是比较简单的,将RichGauge持有的各种指标,封装为对应的Metric,加入到结果即可.

  3. 自动装配:

    在PublicMetricsAutoConfiguration中进行了声明,代码如下:

    @Bean
@ConditionalOnBean(RichGaugeReader.class)
public RichGaugeReaderPublicMetrics richGaugePublicMetrics(
        RichGaugeReader richGaugeReader) {
    return new RichGaugeReaderPublicMetrics(richGaugeReader);
}

    当BeanFactory中存在RichGaugeReader类型的bean时生效.

    由于默认情况下,没有 RichGaugeReader类型的bean,因此, RichGaugeReaderPublicMetrics不会进行自动装配.

    证明如下:

    访问http://127.0.0.1:8080/autoconfig,可以看到如下内容:

    PublicMetricsAutoConfiguration#richGaugePublicMetrics: { notMatched: [ { condition: "OnBeanCondition", message: "@ConditionalOnBean (types: org.springframework.boot.actuate.metrics.rich.RichGaugeReader; SearchStrategy: all) did not find any beans" }
],
matched: [ ]
}
    原文作者：Spring Boot
    原文地址: https://blog.csdn.net/qq_26000415/article/details/79212536
    本文转自网络文章，转载此文章仅为分享知识，如有侵权，请联系博主进行删除。
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