3W字干货深入分析基于Micrometer和Prometheus实现度量和监控的方案（上）

MeterRegistry registry = new SimpleMeterRegistry();
Counter counter = registry.counter("counter");
counter.increment();
复制代码

CompositeMeterRegistry composite = new CompositeMeterRegistry();
Counter compositeCounter = composite.counter("counter");
compositeCounter.increment(); // <- 实际上这一步操作是无效的,但是不会报错
SimpleMeterRegistry simple = new SimpleMeterRegistry();
composite.add(simple);  // <- 向CompositeMeterRegistry实例中添加SimpleMeterRegistry实例
compositeCounter.increment();  // <-计数成功
复制代码

Metrics.addRegistry(new SimpleMeterRegistry());
Counter counter = Metrics.counter("counter", "tag-1", "tag-2");
counter.increment();
复制代码

MeterRegistry registry = ...
registry.timer("http.server.requests");
复制代码

MeterRegistry registry = ...
registry.counter("database.calls", "db", "users")
registry.counter("http.requests", "uri", "/api/users")
复制代码

MeterRegistry registry = ...
registry.counter("calls", "class", "database", "db", "users");
registry.counter("calls", "class", "http", "uri", "/api/users");
复制代码

MeterRegistry registry = ...
registry.config().commonTags("stack", "prod", "region", "us-east-1");
// 和上面的意义是一样的
registry.config().commonTags(Arrays.asList(Tag.of("stack", "prod"), Tag.of("region", "us-east-1"))); 
复制代码

public interface Tag extends Comparable<Tag> {
    String getKey();
    String getValue();
    static Tag of(String key, String value) {
        return new ImmutableTag(key, value);
    }
    default int compareTo(Tag o) {
        return this.getKey().compareTo(o.getKey());
    }
}
复制代码

MeterRegistry registry = ...
registry.config()
    .meterFilter(MeterFilter.ignoreTags("http"))
    .meterFilter(MeterFilter.denyNameStartsWith("jvm"));
复制代码

MeterRegistry meterRegistry = new SimpleMeterRegistry();
Counter counter = meterRegistry.counter("http.request", "createOrder", "/order/create");
counter.increment();
System.out.println(counter.measure()); // [Measurement{statistic='COUNT', value=1.0}]
复制代码

//实体
@Data
public class Order {
    private String orderId;
    private Integer amount;
    private String channel;
    private LocalDateTime createTime;
}
public class CounterMain {
    private static final DateTimeFormatter FORMATTER = DateTimeFormatter.ofPattern("yyyy-MM-dd");
    static {
        Metrics.addRegistry(new SimpleMeterRegistry());
    }
    public static void main(String[] args) throws Exception {
        Order order1 = new Order();
        order1.setOrderId("ORDER_ID_1");
        order1.setAmount(100);
        order1.setChannel("CHANNEL_A");
        order1.setCreateTime(LocalDateTime.now());
        createOrder(order1);
        Order order2 = new Order();
        order2.setOrderId("ORDER_ID_2");
        order2.setAmount(200);
        order2.setChannel("CHANNEL_B");
        order2.setCreateTime(LocalDateTime.now());
        createOrder(order2);
        Search.in(Metrics.globalRegistry).meters().forEach(each -> {
            StringBuilder builder = new StringBuilder();
            builder.append("name:")
                    .append(each.getId().getName())
                    .append(",tags:")
                    .append(each.getId().getTags())
                    .append(",type:").append(each.getId().getType())
                    .append(",value:").append(each.measure());
            System.out.println(builder.toString());
        });
    }
    private static void createOrder(Order order) {
        //忽略订单入库等操作
        Metrics.counter("order.create",
                "channel", order.getChannel(),
                "createTime", FORMATTER.format(order.getCreateTime())).increment();
    }
}
复制代码

name:order.create,tags:[tag(channel=CHANNEL_A), tag(createTime=2018-11-10)],type:COUNTER,value:[Measurement{statistic='COUNT', value=1.0}]
name:order.create,tags:[tag(channel=CHANNEL_B), tag(createTime=2018-11-10)],type:COUNTER,value:[Measurement{statistic='COUNT', value=1.0}]
复制代码

public class CounterBuilderMain {
 public static void main(String[] args) throws Exception{
  Counter counter = Counter.builder("name")  //名称
    .baseUnit("unit") //基础单位
    .description("desc") //描述
    .tag("tagKey", "tagValue")  //标签
    .register(new SimpleMeterRegistry());//绑定的MeterRegistry
  counter.increment();
 }
}
复制代码

public class FunctionCounterMain {
 public static void main(String[] args) throws Exception {
  MeterRegistry registry = new SimpleMeterRegistry();
  AtomicInteger n = new AtomicInteger(0);
  //这里ToDoubleFunction匿名实现其实可以使用Lambda表达式简化为AtomicInteger::get
  FunctionCounter.builder("functionCounter", n, new ToDoubleFunction<AtomicInteger>() {
   @Override
   public double applyAsDouble(AtomicInteger value) {
    return value.get();
   }
  }).baseUnit("function")
    .description("functionCounter")
    .tag("createOrder", "CHANNEL-A")
    .register(registry);
  //下面模拟三次计数  
  n.incrementAndGet();
  n.incrementAndGet();
  n.incrementAndGet();
 }
}
复制代码

public interface Timer extends Meter {
    ...
    void record(long var1, TimeUnit var3);
    default void record(Duration duration) {
        this.record(duration.toNanos(), TimeUnit.NANOSECONDS);
    }
    <T> T record(Supplier<T> var1);
    <T> T recordCallable(Callable<T> var1) throws Exception;
    void record(Runnable var1);
    default Runnable wrap(Runnable f) {
        return () -> {
            this.record(f);
        };
    }
    default <T> Callable<T> wrap(Callable<T> f) {
        return () -> {
            return this.recordCallable(f);
        };
    }
    long count();
    double totalTime(TimeUnit var1);
    default double mean(TimeUnit unit) {
        return this.count() == 0L ? 0.0D : this.totalTime(unit) / (double)this.count();
    }
    double max(TimeUnit var1);
 ...
}
复制代码

Timer timer = ...
timer.record(() -> dontCareAboutReturnValue());
timer.recordCallable(() -> returnValue());
Runnable r = timer.wrap(() -> dontCareAboutReturnValue());
Callable c = timer.wrap(() -> returnValue());
复制代码

public class TimerMain {
 private static final Random R = new Random();
 static {
  Metrics.addRegistry(new SimpleMeterRegistry());
 }
 public static void main(String[] args) throws Exception {
  Order order1 = new Order();
  order1.setOrderId("ORDER_ID_1");
  order1.setAmount(100);
  order1.setChannel("CHANNEL_A");
  order1.setCreateTime(LocalDateTime.now());
  Timer timer = Metrics.timer("timer", "createOrder", "cost");
  timer.record(() -> createOrder(order1));
 }
 private static void createOrder(Order order) {
  try {
   TimeUnit.SECONDS.sleep(R.nextInt(5)); //模拟方法耗时
  } catch (InterruptedException e) {
   //no-op
  }
 }
}
复制代码

MeterRegistry registry = ...
Timer timer = Timer
    .builder("my.timer")
    .description("a description of what this timer does") // 可选
    .tags("region", "test") // 可选
    .register(registry);
复制代码

Timer.Sample sample = Timer.start(registry);
// 这里做业务逻辑
Response response = ...
sample.stop(registry.timer("my.timer", "response", response.status()));
复制代码

public interface FunctionTimer extends Meter {
    static <T> Builder<T> builder(String name, T obj, ToLongFunction<T> countFunction,
                                  ToDoubleFunction<T> totalTimeFunction,
                                  TimeUnit totalTimeFunctionUnit) {
        return new Builder<>(name, obj, countFunction, totalTimeFunction, totalTimeFunctionUnit);
    }
 ...
} 
复制代码

IMap<?, ?> cache = ...; // 假设使用了Hazelcast缓存
registry.more().timer("cache.gets.latency", Tags.of("name", cache.getName()), cache,
    c -> c.getLocalMapStats().getGetOperationCount(),  //实际上就是cache的一个方法，记录缓存生命周期初始化的增量(个数)
    c -> c.getLocalMapStats().getTotalGetLatency(),  // Get操作的延迟时间总量，可以理解为耗时
    TimeUnit.NANOSECONDS
);
复制代码

public class FunctionTimerMain {
 public static void main(String[] args) throws Exception {
  //这个是为了满足参数,暂时不需要理会
  Object holder = new Object();
  AtomicLong totalTimeNanos = new AtomicLong(0);
  AtomicLong totalCount = new AtomicLong(0);
  FunctionTimer.builder("functionTimer", holder, p -> totalCount.get(), 
    p -> totalTimeNanos.get(), TimeUnit.NANOSECONDS)
    .register(new SimpleMeterRegistry());
  totalTimeNanos.addAndGet(10000000);
  totalCount.incrementAndGet();
 }
}
复制代码

@Timed(value = "aws.scrape", longTask = true)
@Scheduled(fixedDelay = 360000)
void scrapeResources() {
    //这里做相对耗时的业务逻辑
}
复制代码

public class LongTaskTimerMain {
    public static void main(String[] args) throws Exception{
        MeterRegistry meterRegistry = new SimpleMeterRegistry();
        LongTaskTimer longTaskTimer = meterRegistry.more().longTaskTimer("longTaskTimer");
        longTaskTimer.record(() -> {
             //这里编写Task的逻辑
        });
             //或者这样
        Metrics.more().longTaskTimer("longTaskTimer").record(()-> {
             //这里编写Task的逻辑
        });
    }
}
复制代码

List<String> list = registry.gauge("listGauge", Collections.emptyList(), new ArrayList<>(), List::size); 
List<String> list2 = registry.gaugeCollectionSize("listSize2", Tags.empty(), new ArrayList<>()); 
Map<String, Integer> map = registry.gaugeMapSize("mapGauge", Tags.empty(), new HashMap<>());
复制代码

AtomicInteger n = registry.gauge("numberGauge", new AtomicInteger(0));
n.set(1);
n.set(2);
复制代码

//一般我们不需要操作Gauge实例
Gauge gauge = Gauge
    .builder("gauge", myObj, myObj::gaugeValue)
    .description("a description of what this gauge does") // 可选
    .tags("region", "test") // 可选
    .register(registry);
复制代码

public class GaugeMain {
    private static final MeterRegistry MR = new SimpleMeterRegistry();
    private static final BlockingQueue<Message> QUEUE = new ArrayBlockingQueue<>(500);
    private static BlockingQueue<Message> REAL_QUEUE;
    static {
        REAL_QUEUE = MR.gauge("messageGauge", QUEUE, Collection::size);
    }
    public static void main(String[] args) throws Exception {
        consume();
        Message message = new Message();
        message.setUserId(1L);
        message.setContent("content");
        REAL_QUEUE.put(message);
    }
    private static void consume() throws Exception {
        new Thread(() -> {
            while (true) {
                try {
                    Message message = REAL_QUEUE.take();
                    //handle message
                    System.out.println(message);
                } catch (InterruptedException e) {
                    //no-op
                }
            }
        }).start();
    }
}
复制代码

public class TimeGaugeMain {
    private static final SimpleMeterRegistry R = new SimpleMeterRegistry();
    public static void main(String[] args) throws Exception {
        AtomicInteger count = new AtomicInteger();
        TimeGauge.Builder<AtomicInteger> timeGauge = TimeGauge.builder("timeGauge", count,
                TimeUnit.SECONDS, AtomicInteger::get);
        timeGauge.register(R);
        count.addAndGet(10086);
        print();
        count.set(1);
        print();
    }
    private static void print() throws Exception {
        Search.in(R).meters().forEach(each -> {
            StringBuilder builder = new StringBuilder();
            builder.append("name:")
                    .append(each.getId().getName())
                    .append(",tags:")
                    .append(each.getId().getTags())
                    .append(",type:").append(each.getId().getType())
                    .append(",value:").append(each.measure());
            System.out.println(builder.toString());
        });
    }
}
//输出
name:timeGauge,tags:[],type:GAUGE,value:[Measurement{statistic='VALUE', value=10086.0}]
name:timeGauge,tags:[],type:GAUGE,value:[Measurement{statistic='VALUE', value=1.0}]
复制代码

DistributionSummary summary = registry.summary("response.size");
复制代码

DistributionSummary summary = DistributionSummary
    .builder("response.size")
    .description("a description of what this summary does") // 可选
    .baseUnit("bytes") // 可选
    .tags("region", "test") // 可选
    .scale(100) // 可选
    .register(registry);
复制代码

public class DistributionSummaryMain {
    private static final DistributionSummary DS = DistributionSummary.builder("cacheHitPercent")
            .register(new SimpleMeterRegistry());
    private static final LoadingCache<String, String> CACHE = CacheBuilder.newBuilder()
            .maximumSize(1000)
            .recordStats()
            .expireAfterWrite(60, TimeUnit.SECONDS)
            .build(new CacheLoader<String, String>() {
                @Override
                public String load(String s) throws Exception {
                     return selectFromDatabase();
                }
            });
    public static void main(String[] args) throws Exception {
        String key = "doge";
        String value = CACHE.get(key);
        record();
    }
    private static void record() throws Exception {
        CacheStats stats = CACHE.stats();
        BigDecimal hitCount = new BigDecimal(stats.hitCount());
        BigDecimal requestCount = new BigDecimal(stats.requestCount());
        DS.record(hitCount.divide(requestCount, 2, BigDecimal.ROUND_HALF_DOWN).doubleValue());
    }
}
复制代码