这个 Redis 连接池的新监控方式针不戳~我再加一点佐料

public interface EventBus {
    // 获取 Flux，通过 Flux 订阅，可以允许多个订阅者
    Flux<Event> get();
    // 发布事件
    void publish(Event event);
}

public class DefaultEventBus implements EventBus {
    private final DirectProcessor<Event> bus;
    private final FluxSink<Event> sink;
    private final Scheduler scheduler;
    private final EventRecorder recorder = EventRecorder.getInstance();
    public DefaultEventBus(Scheduler scheduler) {
        this.bus = DirectProcessor.create();
        this.sink = bus.sink();
        this.scheduler = scheduler;
    }
    @Override
    public Flux<Event> get() {
        //如果消费不过来直接丢弃
        return bus.onBackpressureDrop().publishOn(scheduler);
    }
    @Override
    public void publish(Event event) {
        //调用 recorder 记录
        recorder.record(event);
        //调用 recorder 记录之后，再发布事件
        sink.next(event);
    }
}

public void record(Event event) {
    LettuceAssert.notNull(event, "Event must not be null");
    //使用 Event 创建对应的 JFR Event，之后直接 commit，即提交这个 JFR 事件到 JVM 的 JFR 记录中
    jdk.jfr.Event jfrEvent = createEvent(event);
    if (jfrEvent != null) {
        jfrEvent.commit();
    }
}
private jdk.jfr.Event createEvent(Event event) {
    try {
        //获取构造器，如果构造器是 Object 的构造器，代表没有找到这个 Event 对应的 JFR Event 的构造器
        Constructor<?> constructor = getEventConstructor(event);
        if (constructor.getDeclaringClass() == Object.class) {
            return null;
        }
        //使用构造器创建 JFR Event
        return (jdk.jfr.Event) constructor.newInstance(event);
    } catch (ReflectiveOperationException e) {
        throw new IllegalStateException(e);
    }
}
//Event 对应的 JFR Event 构造器缓存
private final Map<Class<?>, Constructor<?>> constructorMap = new HashMap<>();
private Constructor<?> getEventConstructor(Event event) throws NoSuchMethodException {
    Constructor<?> constructor;
    //简而言之，就是查看缓存 Map 中是否存在这个 class 对应的 JFR Event 构造器，有则返回，没有则尝试发现
    synchronized (constructorMap) {
        constructor = constructorMap.get(event.getClass());
    }
    if (constructor == null) {
        //这个发现的方式比较粗暴，直接寻找与当前 Event 的同包路径下的以 Jfr 开头，后面跟着当前 Event 名称的类是否存在
        //如果存在就获取他的第一个构造器（无参构造器），不存在就返回 Object 的构造器
        String jfrClassName = event.getClass().getPackage().getName() + ".Jfr" + event.getClass().getSimpleName();
        Class<?> eventClass = LettuceClassUtils.findClass(jfrClassName);
        if (eventClass == null) {
            constructor = Object.class.getConstructor();
        } else {
            constructor = eventClass.getDeclaredConstructors()[0];
            constructor.setAccessible(true);
        }
        synchronized (constructorMap) {
            constructorMap.put(event.getClass(), constructor);
        }
    }
    return constructor;
}

private Map<CommandLatencyId, CommandMetrics> latencies;

package io.lettuce.core.event.metrics;
import jdk.jfr.Category;
import jdk.jfr.Event;
import jdk.jfr.Label;
import jdk.jfr.StackTrace;
@Category({ "Lettuce", "Command Events" })
@Label("Command Latency Trigger")
@StackTrace(false)
public class JfrCommandLatencyEvent extends Event {
    private final int size;
    public JfrCommandLatencyEvent(CommandLatencyEvent commandLatencyEvent) {
        this.size = commandLatencyEvent.getLatencies().size();
        commandLatencyEvent.getLatencies().forEach((commandLatencyId, commandMetrics) -> {
            JfrCommandLatency jfrCommandLatency = new JfrCommandLatency(commandLatencyId, commandMetrics);
            jfrCommandLatency.commit();
        });
    }
}
package io.lettuce.core.event.metrics;
import io.lettuce.core.metrics.CommandLatencyId;
import io.lettuce.core.metrics.CommandMetrics;
import jdk.jfr.Category;
import jdk.jfr.Event;
import jdk.jfr.Label;
import jdk.jfr.StackTrace;
import java.util.concurrent.TimeUnit;
@Category({ "Lettuce", "Command Events" })
@Label("Command Latency")
@StackTrace(false)
public class JfrCommandLatency extends Event {
    private final String remoteAddress;
    private final String commandType;
    private final long count;
    private final TimeUnit timeUnit;
    private final long firstResponseMin;
    private final long firstResponseMax;
    private final String firstResponsePercentiles;
    private final long completionResponseMin;
    private final long completionResponseMax;
    private final String completionResponsePercentiles;
    public JfrCommandLatency(CommandLatencyId commandLatencyId, CommandMetrics commandMetrics) {
        this.remoteAddress = commandLatencyId.remoteAddress().toString();
        this.commandType = commandLatencyId.commandType().toString();
        this.count = commandMetrics.getCount();
        this.timeUnit = commandMetrics.getTimeUnit();
        this.firstResponseMin = commandMetrics.getFirstResponse().getMin();
        this.firstResponseMax = commandMetrics.getFirstResponse().getMax();
        this.firstResponsePercentiles = commandMetrics.getFirstResponse().getPercentiles().toString();
        this.completionResponseMin = commandMetrics.getCompletion().getMin();
        this.completionResponseMax = commandMetrics.getCompletion().getMax();
        this.completionResponsePercentiles = commandMetrics.getCompletion().getPercentiles().toString();
    }
}

@Configuration(proxyBeanMethods = false)
@Import({LettuceConfiguration.class})
//需要强制在 RedisAutoConfiguration 进行自动装载
@AutoConfigureBefore(RedisAutoConfiguration.class)
public class LettuceAutoConfiguration {
}
import io.lettuce.core.event.DefaultEventPublisherOptions;
import io.lettuce.core.metrics.DefaultCommandLatencyCollector;
import io.lettuce.core.metrics.DefaultCommandLatencyCollectorOptions;
import io.lettuce.core.resource.DefaultClientResources;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import java.time.Duration;
@Configuration(proxyBeanMethods = false)
public class LettuceConfiguration {
    /**
     * 每 10s 采集一次命令统计
     * @return
     */
    @Bean
    public DefaultClientResources getDefaultClientResources() {
        DefaultClientResources build = DefaultClientResources.builder()
                .commandLatencyRecorder(
                        new DefaultCommandLatencyCollector(
                                //开启 CommandLatency 事件采集，并且配置每次采集后都清空数据
                                DefaultCommandLatencyCollectorOptions.builder().enable().resetLatenciesAfterEvent(true).build()
                        )
                )
                .commandLatencyPublisherOptions(
                        //每 10s 采集一次命令统计
                        DefaultEventPublisherOptions.builder().eventEmitInterval(Duration.ofSeconds(10)).build()
                ).build();
        return build;
    }
}