spring boot 源码解析46-MetricReader

2019年3月18日 311次阅读来源: Spring Boot

前言

本文来介绍MetricReader的实现,其类图如下:

《spring boot 源码解析46-MetricReader》

其中如下实现在之前的文章中有介绍,本文不在对其进行说明:

BufferMetricReader–> 在 spring boot 源码解析44-PrefixMetricReader,PrefixMetricWriter,MultiMetricRepository 中有说明
MetricRepository,InMemoryMetricRepository–>在 spring boot 源码解析37-CounterService详解中有说明
RedisMetricRepository–>在spring boot 源码解析41-CounterWriter,GaugeWriter解析中介绍

解析

MetricReader

MetricReader–> 个简单的读取数据的接口–>用来审查Metric.代码如下:

public interface MetricReader {

    // 获得1个是指定name的Metric的实例(通常会返回最后1个记录的)Metric,如果没有对应的,则返回null
    Metric<?> findOne(String metricName);

    // 获得所有MetricReader持有的Metric
    Iterable<Metric<?>> findAll();

    // 获得MetricReader持有的Metric得到数量
    long count();

}

CompositeMetricReader

CompositeMetricReader–> 组合模式,所有的方法都是调用其内部持有的MetricReader依次去处理.代码如下:

public class CompositeMetricReader implements MetricReader {

    private final List<MetricReader> readers = new ArrayList<MetricReader>();

    public CompositeMetricReader(MetricReader... readers) {
        Collections.addAll(this.readers, readers);
    }

    @Override
    public Metric<?> findOne(String metricName) {
        for (MetricReader delegate : this.readers) {
            Metric<?> value = delegate.findOne(metricName);
            if (value != null) {
                return value;
            }
        }
        return null;
    }

    @Override
    public Iterable<Metric<?>> findAll() {
        List<Metric<?>> values = new ArrayList<Metric<?>>((int) count());
        for (MetricReader delegate : this.readers) {
            Iterable<Metric<?>> all = delegate.findAll();
            for (Metric<?> value : all) {
                values.add(value);
            }
        }
        return values;
    }

    @Override
    public long count() {
        long count = 0;
        for (MetricReader delegate : this.readers) {
            count += delegate.count();

        }
        return count;
    }

}

实例化地方如下:

《spring boot 源码解析46-MetricReader》

关于这两处的调用点会在后续的文章中有介绍

MetricRegistryMetricReader

MetricRegistryMetricReader–> 实现了MetricReader, MetricRegistryListener,从MetricRegistry中读取metrics的MetricReader,Gauges 和 Counters 被反射成1个单一值,Timers,Meters and Histograms 被扩展到1个metrics的(包含所有Number的属性的)集合中.

字段,构造器如下:

private static final Log logger = LogFactory.getLog(MetricRegistryMetricReader.class);

// key--> Histograms,Meter,Timer,Snapshot 对应的class， value --> 该class中属性是number类型的属性名
private static final Map<Class<?>, Set<String>> numberKeys = new ConcurrentHashMap<Class<?>, Set<String>>();

private final Object monitor = new Object();

// key-->metricName,value-->MetricRegistry 中对应的Metric 名
private final Map<String, String> names = new ConcurrentHashMap<String, String>();

// key--> MetricRegistry 中对应的Metric 名 value --> metricName
private final MultiValueMap<String, String> reverse = new LinkedMultiValueMap<String, String>();

private final MetricRegistry registry;

public MetricRegistryMetricReader(MetricRegistry registry) {
    this.registry = registry;
    registry.addListener(this);
}

方法实现如下:

onGaugeAdded–>当Gauge添加到MetricRegistry时触发.代码如下:

public void onGaugeAdded(String name, Gauge<?> gauge) {
    this.names.put(name, name);
    synchronized (this.monitor) {
        this.reverse.add(name, name);
    }
}

onCounterAdded–> 当Counter添加到MetricRegistry时触发.代码如下:

public void onCounterAdded(String name, Counter counter) {
    this.names.put(name, name);
    synchronized (this.monitor) {
        this.reverse.add(name, name);
    }
}

onHistogramAdded–> 当Histogram添加到MetricRegistry时触发.代码如下:

public void onHistogramAdded(String name, Histogram histogram) {
    for (String key : getNumberKeys(histogram)) {
        String metricName = name + "." + key;
        this.names.put(metricName, name);
        synchronized (this.monitor) {
            this.reverse.add(name, metricName);
        }
    }
    for (String key : getNumberKeys(histogram.getSnapshot())) {
        String metricName = name + ".snapshot." + key;
        this.names.put(metricName, name);
        synchronized (this.monitor) {
            this.reverse.add(name, metricName);
        }
    }
}

获得Histogram中属性是Number类型的属性名,此时获得的是count 依次处理之
1. 将Number类型的属性名依次加上指定的name前缀生成metricName
2. 添加到names,reverse中
获得Snapshot中属性是Number类型的属性名,依次处理之,将Number类型的属性名依次加上指定的name前缀生成metricName,添加到names,reverse中.此时获得的是75thPercentile, 98thPercentile, min, 95thPercentile, 99thPercentile, median, max, mean, 999thPercentile, stdDev.

getNumberKeys方法如下:

private static Set<String> getNumberKeys(Object metric) {
    // 1. 尝试从缓存中获取,如果获取不到的话,则进行初始化
    Set<String> result = numberKeys.get(metric.getClass());
    if (result == null) {
        result = new HashSet<String>();
    }
    if (result.isEmpty()) {
        // 2. 如果result 等于null,意味着是第1次创建，则获得metric所有的PropertyDescriptor,遍历之
        for (PropertyDescriptor descriptor : BeanUtils
                .getPropertyDescriptors(metric.getClass())) {
            // 2.1 如果属性的类型是Number类型的话,则加入到result中
            if (ClassUtils.isAssignable(Number.class, descriptor.getPropertyType())) {
                result.add(descriptor.getName());
            }
        }
        // 3. 加入到numberKeys中
        numberKeys.put(metric.getClass(), result);
    }
    return result;
}

onMeterAdded–>当Meter添加到MetricRegistry时触发.代码如下:

public void onMeterAdded(String name, Meter meter) {
    for (String key : getNumberKeys(meter)) {
        String metricName = name + "." + key;
        this.names.put(metricName, name);
        synchronized (this.monitor) {
            this.reverse.add(name, metricName);
        }
    }
}

获得Meter中属性是Number类型的属性名,依次处理之,将Number类型的属性名依次加上指定的name前缀生成metricName,添加到names,reverse中.此时获得的是count,fifteenMinuteRate,fiveMinuteRate,meanRate,oneMinuteRate

onTimerAdded–> 当Timer添加到MetricRegistry时触发.代码如下:

public void onTimerAdded(String name, Timer timer) {
        for (String key : getNumberKeys(timer)) {
        String metricName = name + "." + key;
        this.names.put(metricName, name);
        synchronized (this.monitor) {
            this.reverse.add(name, metricName);
        }
    }
    for (String key : getNumberKeys(timer.getSnapshot())) {
        String metricName = name + ".snapshot." + key;
        this.names.put(metricName, name);
        synchronized (this.monitor) {
            this.reverse.add(name, metricName);
        }
    }
}

获得Timer中属性是Number类型的属性名,依次处理之,将Number类型的属性名依次加上指定的name前缀生成metricName,添加到names,reverse中.此时获得的是count,fifteenMinuteRate,fiveMinuteRate,meanRate,oneMinuteRate
获得Snapshot中属性是Number类型的属性名,依次处理之,将Number类型的属性名依次加上指定的name前缀生成metricName,添加到names,reverse中.此时获得的是75thPercentile, 98thPercentile, min, 95thPercentile, 99thPercentile, median, max, mean, 999thPercentile, stdDev.

onGaugeRemoved,onCounterRemoved,onHistogramRemoved,onMeterRemoved,onTimerRemoved最终都会调用remove方法来处理.代码如下:

private void remove(String name) {
    List<String> keys;
    synchronized (this.monitor) {
        keys = this.reverse.remove(name);
    }
    if (keys != null) {
        for (String key : keys) {
            this.names.remove(name + "." + key);
        }
    }
}

从reverse,names中删除

findOne,代码如下:

public Metric<?> findOne(String metricName) {
    // 1. 从names中获得指定metricName在MetricRegistry中注册的名字,如果不存在则返回null
    String name = this.names.get(metricName);
    if (name == null) {
        return null;
    }
    // 2. 从MetricRegistry中获得对应的Metric,如果获取不到,则返回null
    com.codahale.metrics.Metric metric = this.registry.getMetrics().get(name);
    if (metric == null) {
        return null;
    }
    // 3. 如果是Counter
    if (metric instanceof Counter) {
        Counter counter = (Counter) metric;
        return new Metric<Number>(metricName, counter.getCount());
    }
    // 4. 如果是Gauge
    if (metric instanceof Gauge) {
        Object value = ((Gauge<?>) metric).getValue();
        // 4.1 如果统计值是number类型的,则实例化Metric 返回,否则返回null
        if (value instanceof Number) {
            return new Metric<Number>(metricName, (Number) value);
        }
        if (logger.isDebugEnabled()) {
            logger.debug("Ignoring gauge '" + name + "' (" + metric
                    + ") as its value is not a Number");
        }
        return null;
    }
    // 5. 如果是抽样
    if (metric instanceof Sampling) {
        // 5.1 如果metricName 含有.snapshot.
        if (metricName.contains(".snapshot.")) {

            // 5.2 获得对应的测量值
            Number value = getMetric(((Sampling) metric).getSnapshot(), metricName);
            // 5.3 如果该metricName对应的metric为Timer,则将其值转换为毫秒
            if (metric instanceof Timer) {
                // convert back to MILLISEC
                value = TimeUnit.MILLISECONDS.convert(value.longValue(),
                        TimeUnit.NANOSECONDS);
            }
            // 5.4 返回
            return new Metric<Number>(metricName, value);
        }
    }
    // 6. 获得对应的测量值 封装为Metric 后返回
    return new Metric<Number>(metricName, getMetric(metric, metricName));
}

从names中获得指定metricName在MetricRegistry中注册的名字,如果不存在则返回null
从MetricRegistry中获得对应的Metric,如果获取不到,则返回null
如果是Counter,则直接返回对应的Metric
如果是Gauge
1. 如果统计值是number类型的,则实例化Metric 返回,否则返回null
如果是Sampling的实例.
1. 如果metricName 含有.snapshot.
  1. 获得对应的测量值
  2. 如果该metricName对应的metric为Timer,则将其值转换为毫秒
  3. 返回Metric

获得对应的测量值封装为Metric 后返回.代码如下:

private static Number getMetric(Object metric, String metricName) {
    // 1. 获取metricName 最后1个点的后的字符串
    String key = StringUtils.getFilenameExtension(metricName);
    // 2. 将metric 包装为BeanWrapperImpl,直接读取该key所对应的值
    return (Number) new BeanWrapperImpl(metric).getPropertyValue(key);
}

findAll,代码如下:

public Iterable<Metric<?>> findAll() {
    return new Iterable<Metric<?>>() {
        @Override
        public Iterator<Metric<?>> iterator() {
            Set<Metric<?>> metrics = new HashSet<Metric<?>>();
            // 1. 遍历names
            for (String name : MetricRegistryMetricReader.this.names.keySet()) {
                // 2. 根据name 获得对应的Metric,如果不等于null,则添加到metrics中
                Metric<?> metric = findOne(name);
                if (metric != null) {
                    metrics.add(metric);
                }
            }
            // 3. 返回
            return metrics.iterator();
        }
    };
}

count.代码如下:

public long count() {
    return this.names.size();
}

自动装配:

在MetricsDropwizardAutoConfiguration中声明,如下:

@Configuration
@ConditionalOnClass(MetricRegistry.class)
@AutoConfigureBefore(MetricRepositoryAutoConfiguration.class)
public class MetricsDropwizardAutoConfiguration {
    ....

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

当满足如下条件时生效:

ConditionalOnClass(MetricRegistry.class)–> 在类路径下存在MetricRegistry.class

MetricsEndpointMetricReader

后续文章分析

AggregateMetricReader

注意,该类没有自动装配

该类的字段,构造器如下:
```
private MetricReader source;

private String keyPattern = "d.d";

// 应用到所有的输出metrics中.
private String prefix = "aggregate.";

public AggregateMetricReader(MetricReader source) {
    this.source = source;
}
```
keyPattern 说明如下:
指定该类对于repository中的key,如何操作.这些key在repository中被假定为是.分隔的,且给定的格式也必须是同样的格式,比如:”d.d.k.d”.keyPattern 需要与repository中的keys进行匹配,并将应用如下规则:
1. d–>丢弃这些key段(对全局前缀比如系统标识或者聚合keys a.k.a的物理标识 )
2. k–> 保持原样不需要进行改变(对逻辑标识有用比如app的名字)
默认是d.d(假设有全局前缀其长度为2)

方法实现如下:

findOne,代码如下:

public Metric<?> findOne(String metricName) {
    // 1. 如果不是指定前缀开头的,返回null
    if (!metricName.startsWith(this.prefix)) {
        return null;
    }
    // 2 . 实例化InMemoryMetricRepository
    InMemoryMetricRepository result = new InMemoryMetricRepository();
    // 3. 去除前缀
    String baseName = metricName.substring(this.prefix.length());
    // 4. 获取source中的所有Metric,遍历
    for (Metric<?> metric : this.source.findAll()) {
        // 4.1 获得SourceKey
        String name = getSourceKey(metric.getName());
        if (baseName.equals(name)) {
            update(result, name, metric);
        }
    }
    // 5. 查找
    return result.findOne(metricName);
}

如果不是指定前缀开头的,返回nul
实例化InMemoryMetricRepository
去除前缀

获取source中的所有Metric,遍历

获得SourceKey.代码如下:

private String getSourceKey(String name) {
    // 1. 将给定的name,本类中的keyPattern 通过.进行分割
    String[] keys = StringUtils.delimitedListToStringArray(name, ".");
    String[] patterns = StringUtils.delimitedListToStringArray(this.keyPattern, ".");
    StringBuilder builder = new StringBuilder();
    // 2. 依次遍历patterns,如果其值是k,则加入到builder中
    for (int i = 0; i < patterns.length; i++) {
        if ("k".equals(patterns[i])) {
            builder.append(builder.length() > 0 ? "." : "");
            builder.append(keys[i]);
        }
    }
    // 3.  此时发生在 keys.length > patterns.length 的情况,那么就需要依次的将keys中的数据加入到builder中
    for (int i = patterns.length; i < keys.length; i++) {
        builder.append(builder.length() > 0 ? "." : "");
        builder.append(keys[i]);
    }
    // 4. 返回
    return builder.toString();
}

将给定的name,本类中的keyPattern 通过.进行分割
依次遍历patterns,如果其值是k,则加入到builder中
如果发生 keys.length > patterns.length 的情况,那么就需要依次的将keys中的数据加入到builder中
返回

如果SourceKey和baseName相同的话,则添加到result中.代码如下:

private void update(InMemoryMetricRepository result, String key, Metric<?> metric) {
    // 1. 将key加上前缀
    String name = this.prefix + key;
    // 2. 从InMemoryMetricRepository 进行查找,如果找不到的话,则实例化1个,此时一般情况下都会实例化的
    Metric<?> aggregate = result.findOne(name);
    if (aggregate == null) {
        aggregate = new Metric<Number>(name, metric.getValue(),
                metric.getTimestamp());
    }
    else if (key.contains("counter.")) {
        // accumulate all values
        aggregate = new Metric<Number>(name,
                metric.increment(aggregate.getValue().intValue()).getValue(),
                metric.getTimestamp());
    }
    else if (aggregate.getTimestamp().before(metric.getTimestamp())) {
        // sort by timestamp and only take the latest
        aggregate = new Metric<Number>(name, metric.getValue(),
                metric.getTimestamp());
    }
    // 3. 添加
    result.set(aggregate);
}

将key加上前缀
从InMemoryMetricRepository 进行查找,如果找不到的话,则实例化1个,此时一般情况下都会实例化的
添加

查找

findAll,count的实现和findOne类似,如下:

@Override
public Iterable<Metric<?>> findAll() {
    InMemoryMetricRepository result = new InMemoryMetricRepository();
    for (Metric<?> metric : this.source.findAll()) {
        String key = getSourceKey(metric.getName());
        if (key != null) {
            update(result, key, metric);
        }
    }
    return result.findAll();
}
@Override
public long count() {
    Set<String> names = new HashSet<String>();
    for (Metric<?> metric : this.source.findAll()) {
        String name = getSourceKey(metric.getName());
        if (name != null) {
            names.add(name);
        }
    }
    return names.size();
}

SpringIntegrationMetricReader

SpringIntegrationMetricReader–>基于spring-integration来实现的.

字段,构造器如下:

private final IntegrationManagementConfigurer configurer;

public SpringIntegrationMetricReader(IntegrationManagementConfigurer configurer) {
    this.configurer = configurer;
}

方法实现如下:

findOne–> 默认返回null.代码如下:

public Metric<?> findOne(String metricName) {
    return null;
}

findAll,代码如下:

public Iterable<Metric<?>> findAll() {
    List<Metric<?>> result = new ArrayList<Metric<?>>();
    // 1. 获得配置的Channel,Handler,Source的名字
    String[] channelNames = this.configurer.getChannelNames();
    String[] handlerNames = this.configurer.getHandlerNames();
    String[] sourceNames = this.configurer.getSourceNames();
    // 2.添加Channel的统计
    addChannelMetrics(result, channelNames);
    // 3. 添加Handler的统计
    addHandlerMetrics(result, handlerNames);
    // 3. 添加source的统计
    addSourceMetrics(result, sourceNames);
    // 4. 添加Channel,Handler,Source的数量统计
    result.add(new Metric<Integer>("integration.handlerCount", handlerNames.length));
    result.add(new Metric<Integer>("integration.channelCount", channelNames.length));
    result.add(new Metric<Integer>("integration.sourceCount", sourceNames.length));
    return result;
}

获得配置的Channel,Handler,Source的名字

添加Channel的统计.代码如下:

private void addChannelMetrics(List<Metric<?>> result, String[] names) {
    // 1. 遍历Channel的名字,依次调用addChannelMetrics添加
    for (String name : names) {
        addChannelMetrics(result, name, this.configurer.getChannelMetrics(name));
    }
}

遍历Channel的名字,依次调用addChannelMetrics添加.代码如下:

private void addChannelMetrics(List<Metric<?>> result, String name,
        MessageChannelMetrics metrics) {
    // 1. 在Channel 名字前加上前缀
    String prefix = "integration.channel." + name;
    // 2. 添加该Channel所对应的错误率(每秒)
    result.addAll(getStatistics(prefix + ".errorRate", metrics.getErrorRate()));
    // 3. 添加成功发送数量的统计
    result.add(new Metric<Long>(prefix + ".sendCount", metrics.getSendCountLong()));
    // 4. 添加发送消息的速率统计(每秒)
    result.addAll(getStatistics(prefix + ".sendRate", metrics.getSendRate()));
    if (metrics instanceof PollableChannelManagement) {
        // 5. 如果传入的PollableChannelManagement的实例,则添加拉取数据的统计
        result.add(new Metric<Long>(prefix + ".receiveCount",
                ((PollableChannelManagement) metrics).getReceiveCountLong()));
    }
}

在Channel 名字前加上前缀
添加该Channel所对应的错误率(每秒)
添加成功发送数量的统计
添加发送消息的速率统计(每秒)
如果传入的PollableChannelManagement的实例,则添加拉取数据的统计

getStatistics代码如下:

private Collection<? extends Metric<?>> getStatistics(String name, Statistics stats) {
    List<Metric<?>> metrics = new ArrayList<Metric<?>>();
    metrics.add(new Metric<Double>(name + ".mean", stats.getMean()));
    metrics.add(new Metric<Double>(name + ".max", stats.getMax()));
    metrics.add(new Metric<Double>(name + ".min", stats.getMin()));
    metrics.add(new Metric<Double>(name + ".stdev", stats.getStandardDeviation()));// 标准差
    metrics.add(new Metric<Long>(name + ".count", stats.getCountLong()));
    return metrics;
}

添加Handler的统计.代码如下:

private void addHandlerMetrics(List<Metric<?>> result, String[] names) {
    // 2. 遍历andler的名字,依次调用addHandlerMetrics添加
    for (String name : names) {
        addHandlerMetrics(result, name, this.configurer.getHandlerMetrics(name));
    }
}

遍历andler的名字,依次调用addHandlerMetrics添加.代码如下:

private void addHandlerMetrics(List<Metric<?>> result, String name,
        MessageHandlerMetrics metrics) {
    String prefix = "integration.handler." + name;
    result.addAll(getStatistics(prefix + ".duration", metrics.getDuration()));// 持续时间
    long activeCount = metrics.getActiveCountLong(); // handler 的激活执行数量
    result.add(new Metric<Long>(prefix + ".activeCount", activeCount));
}

添加source的统计.代码如下:

private void addSourceMetrics(List<Metric<?>> result, String[] names) {
    for (String name : names) {
        addSourceMetrics(result, name, this.configurer.getSourceMetrics(name));
    }
}

遍历Sourcer的名字,依次调用addSourceMetrics添加.代码如下:

private void addSourceMetrics(List<Metric<?>> result, String name,
        MessageSourceMetrics sourceMetrics) {
    String prefix = "integration.source." + name;
    result.add(new Metric<Long>(prefix + ".messageCount",
            sourceMetrics.getMessageCountLong())); // 消息数量
}

添加Channel,Handler,Source的数量统计

count–>统计Channel,Handler,Source的次数.代码如下:

public long count() {
    int totalChannelCount = this.configurer.getChannelNames().length;
    int totalHandlerCount = this.configurer.getHandlerNames().length;
    int totalSourceCount = this.configurer.getSourceNames().length;
    return totalChannelCount + totalHandlerCount + totalSourceCount;
}

自动装配:

在IntegrationMetricsConfiguration中声明,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在满足如何条件时生效:

@ConditionalOnClass(EnableIntegrationManagement.class) –> 在类路径下存在EnableIntegrationManagement.class时生效
@ConditionalOnJava(JavaVersion.SEVEN)–> 在jdk1.7及jdk1.7以上的环境中生效

springIntegrationPublicMetrics:

在满足BeanFactory中不存在id为springIntegrationPublicMetrics,类型为MetricReaderPublicMetrics的baan时生效

managementConfigurer:

在满足在当前BeanFactoty中不存在id为integrationManagementConfigurer,类型为IntegrationManagementConfigurer的bean时生效.

    原文作者：Spring Boot
    原文地址: https://blog.csdn.net/qq_26000415/article/details/79192795
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