本文介绍: 寻找到了 com.alibaba.csp.sentinel.transport.command.SimpleHttpCommandCenter#start 的相关收发数据逻辑。触发一次 Http 请求调用后,发现进入了 com.alibaba.csp.sentinel.init.InitExecutor#doInit 断点。这样我们在界面修改就可以持久化到nacos,这里要注意如果在nacos直接修改,控制台上是不能感知到的。关键代码 2:从 ServerSocket 的 accept 方法收数据。

sentinel

功能

  1. 直接拒绝:触发阀值直接抛弃。
  2. 冷启动:在一段时间内针对突发流量缓慢增长处理数量。
    3)匀速器:请求以均匀的速度通过。
  • 降级降级文档
    1)RT 统计时间内,大于预设请求数量,且慢请求大于这个预设比例,则熔断拒绝一段时间。
    2)异常比例,统计时间内,请求总数大于预设请求数,且异常比例大于预设比例,则熔断拒绝一段时间。
    3)异常数,统计时间内,请求总数大于预设请求数量,且异常大于预设数值,则拒绝熔断一段时间。
手动限流案例Demo
  • 根据线程活跃数量进行限流
/**
 * 根据并发数量进行限流
 */
public class Flow_1_Thread_Demo {

    /** 资源 methodA 所有业务逻辑处理完成的数量 **/
    private static AtomicInteger pass = new AtomicInteger();
    /** 资源 methodA 被拒绝的数量 **/
    private static AtomicInteger block = new AtomicInteger();
    /** 资源 methodA 接收到请求的总数量 **/
    private static AtomicInteger total = new AtomicInteger();
    /** 资源 methodA 真正开始干活时就开始计数,表示 methodA 的任务活跃数 **/
    private static AtomicInteger activeThread = new AtomicInteger();

    private static volatile boolean stop = false;
    private static final int threadCount = 100;

    /** 资源 methodA 总共被发起调用的持续时间 **/
    private static int seconds = 15;
    /** 资源 methodB 处理业务时需要消耗的时间,单位:毫秒 **/
    private static volatile int methodBRunningTime = 2000;

    /**
     * 并发数限流
     * 当并发数大于 5 时则进行阻断
     * 反正一直保持最大活跃任务数为 5
     */
    private static void initFlowRule() {
        List<FlowRule> rules = new ArrayList<FlowRule>();
        FlowRule rule = new FlowRule();

        // 设置资源名称为:methodA
        rule.setResource("methodA");

        // 设置限流类型:并发数限流
        rule.setGrade(RuleConstant.FLOW_GRADE_THREAD);

        // 设置并发数限流,对应的限制数值
        rule.setCount(5);

        // 设置需要限制哪些应用,如果没有想好需要限制谁的话,那么采用 default 方式
        rule.setLimitApp("default");

        // 将设置好的规则,添加至列表中,并且加载到限流管理器中
        rules.add(rule);
        FlowRuleManager.loadRules(rules);
        System.out.println("Flow_1_Thread rule loaded: " + rules);
    }

    public static void main(String[] args) throws Exception {
        System.out.println(
            "MethodA will call methodB. After running for a while, methodB becomes fast, "
                + "which make methodA also become fast ");
        // 开启一个线程打印统计信息
        tick();
        // 设置规则
        initFlowRule();
        // 启动现场 不停的发送请求
        for (int i = 0; i < threadCount; i++) {
            Thread entryThread = new Thread(new ThreadRunTask());
            entryThread.setName("working thread");
            entryThread.start();
        }
    }

    private static void tick() {
        Thread timer = new Thread(new TimerTask());
        timer.setName("sentinel-timer-task");
        timer.start();
    }

    /**
     * 打印统计信息 每秒钟输出
     */
    static class TimerTask implements Runnable {

        @Override
        public void run() {
            long start = System.currentTimeMillis();
            System.out.println("begin to statistic!!!");

            long oldTotal = 0;
            long oldPass = 0;
            long oldBlock = 0;
            
            while (!stop) {
                try {
                    TimeUnit.SECONDS.sleep(1);
                } catch (InterruptedException e) {
                }
                long globalTotal = total.get();
                long oneSecondTotal = globalTotal - oldTotal;
                oldTotal = globalTotal;

                long globalPass = pass.get();
                long oneSecondPass = globalPass - oldPass;
                oldPass = globalPass;

                long globalBlock = block.get();
                long oneSecondBlock = globalBlock - oldBlock;
                oldBlock = globalBlock;

                System.out.print("【秒】倒计时: " + seconds + ", ");
                System.out.println((new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS").format(new Date()))
                    + ", 每秒总请求量:" + oneSecondTotal
                    + ", 每秒完成量:" + oneSecondPass
                    + ", 每秒拒绝量:" + oneSecondBlock
                    + ", 每秒活跃量:" + activeThread.get());
                System.out.println();
                if (seconds-- <= 0) {
                    stop = true;
                }
                // 倒数5秒的时候提高MethodB 方法的效率
                if (seconds == 5) {
                    System.out.println("method B 原来执行需要花费 2000 毫秒,改造后只需要花费 20 毫秒,系统即将能处理更多的请求。n");
                    methodBRunningTime = 20;
                }
            }

            long cost = System.currentTimeMillis() - start;
            System.out.println("time cost: " + cost + " ms");
            System.out.println("total:" + total.get() + ", pass:" + pass.get()
                + ", block:" + block.get());
            System.exit(0);
        }
    }

    static class ThreadRunTask implements Runnable {

        @Override
        public void run() {
            while (true) {
                Entry methodA = null;
                try {
                    TimeUnit.MILLISECONDS.sleep(5);
                    // 抢占资源A
                    methodA = SphU.entry("methodA");
                    activeThread.incrementAndGet();
                    // 抢占资源B
                    Entry methodB = SphU.entry("methodB");
                    TimeUnit.MILLISECONDS.sleep(methodBRunningTime);
                    methodB.exit();
                    pass.addAndGet(1);
                } catch (BlockException e1) {
                    // 阻塞的数量
                    block.incrementAndGet();
                } catch (Exception e2) {
                    // biz exception
                } finally {
                    // 请求总数量
                    total.incrementAndGet();
                    if (methodA != null) {
                        methodA.exit();
                        // 活跃数量减
                        activeThread.decrementAndGet();
                    }
                }
            }
        }
    }
}
  • 根据QPS进行限流
/**
 * 根据QPS进行限流
 */
public class Flow_2_Qps_Demo {
    private static final String KEY = "methodA";
    /** 资源 methodA 所有业务逻辑处理完成的数量 **/
    private static AtomicInteger pass = new AtomicInteger();
    /** 资源 methodA 被拒绝的数量 **/
    private static AtomicInteger block = new AtomicInteger();
    /** 资源 methodA 接收到请求的总数量 **/
    private static AtomicInteger total = new AtomicInteger();
    private static volatile boolean stop = false;
    private static final int threadCount = 32;
    /** 资源 methodA 总共被发起调用的持续时间 **/
    private static int seconds = 15;
    private static void initFlowQpsRule() {
        List<FlowRule> rules = new ArrayList<FlowRule>();
        FlowRule rule1 = new FlowRule();
        // 设置资源名称为:methodA
        rule1.setResource(KEY);
        // 设置限流类型:QPS 限流
        rule1.setGrade(RuleConstant.FLOW_GRADE_QPS);
        // 设置 QPS 限流,对应的限制数值
        rule1.setCount(5);
        // 设置 QPS 限流数值满后的应对策略:直接拒绝(该策略为默认策略,可以从 setControlBehavior 方法跟踪进去看)
        // public static final int CONTROL_BEHAVIOR_DEFAULT = 0;
        // public static final int CONTROL_BEHAVIOR_WARM_UP = 1;
        // public static final int CONTROL_BEHAVIOR_RATE_LIMITER = 2;
        // public static final int CONTROL_BEHAVIOR_WARM_UP_RATE_LIMITER = 3;
        // rule1.setControlBehavior()
        
        // 设置需要限制哪些应用,如果没有想好需要限制谁的话,那么采用 default 方式
        rule1.setLimitApp("default");
        // 将设置好的规则,添加至列表中,并且加载到限流管理器中
        rules.add(rule1);
        FlowRuleManager.loadRules(rules);
        System.out.println("Flow_2_Qps rule loaded: " + rules);
    }
    public static void main(String[] args) throws Exception {
        initFlowQpsRule();

        tick();
        // first make the system run on a very low condition
        simulateTraffic();
        System.out.println("===== begin to do flow control");
        System.out.println("only 5 requests per second can pass");
    }
    private static void simulateTraffic() {
        for (int i = 0; i < threadCount; i++) {
            Thread t = new Thread(new RunTask());
            t.setName("simulate-traffic-Task");
            t.start();
        }
    }
    private static void tick() {
        Thread timer = new Thread(new TimerTask());
        timer.setName("sentinel-timer-task");
        timer.start();
    }
    static class TimerTask implements Runnable {
        @Override
        public void run() {
            long start = System.currentTimeMillis();
            System.out.println("begin to statistic!!!");

            long oldTotal = 0;
            long oldPass = 0;
            long oldBlock = 0;
            while (!stop) {
                try {
                    TimeUnit.SECONDS.sleep(1);
                } catch (InterruptedException e) {
                }
                long globalTotal = total.get();
                long oneSecondTotal = globalTotal - oldTotal;
                oldTotal = globalTotal;

                long globalPass = pass.get();
                long oneSecondPass = globalPass - oldPass;
                oldPass = globalPass;

                long globalBlock = block.get();
                long oneSecondBlock = globalBlock - oldBlock;
                oldBlock = globalBlock;

                System.out.print("【秒】倒计时: " + seconds + ", ");
                System.out.println((new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS").format(new Date()))
                        + ", 每秒总请求量:" + oneSecondTotal
                        + ", 每秒完成量:" + oneSecondPass
                        + ", 每秒拒绝量:" + oneSecondBlock);
                System.out.println();
                if (seconds-- <= 0) {
                    stop = true;
                }
            }

            long cost = System.currentTimeMillis() - start;
            System.out.println("time cost: " + cost + " ms");
            System.out.println("total:" + total.get() + ", pass:" + pass.get()
                + ", block:" + block.get());
            System.exit(0);
        }
    }

    static class RunTask implements Runnable {
        @Override
        public void run() {
            while (!stop) {
                Entry entry = null;

                try {
                    entry = SphU.entry(KEY);
                    // token acquired, means pass
                    pass.addAndGet(1);
                } catch (BlockException e1) {
                    block.incrementAndGet();
                } catch (Exception e2) {
                    // biz exception
                } finally {
                    total.incrementAndGet();
                    if (entry != null) {
                        entry.exit();
                    }
                }

                Random random2 = new Random();
                try {
                    TimeUnit.MILLISECONDS.sleep(random2.nextInt(50));
                } catch (InterruptedException e) {
                    // ignore
                }
            }
        }
    }
}
  • 冷启动
    也就是在一定的时间内慢慢可以达到我们处理请求的峰值。
public class Flow_3_WarmUp_Demo {
    private static final String KEY = "methodA";
    /** 资源 methodA 所有业务逻辑处理完成的数量 **/
    private static AtomicInteger pass = new AtomicInteger();
    /** 资源 methodA 被拒绝的数量 **/
    private static AtomicInteger block = new AtomicInteger();
    /** 资源 methodA 接收到请求的总数量 **/
    private static AtomicInteger total = new AtomicInteger();
    private static volatile boolean stop = false;
    private static final int threadCount = 100;
    /** 资源 methodA 总共被发起调用的持续时间 **/
    private static int seconds = 16;
    private static void initFlowRule() {
        List<FlowRule> rules = new ArrayList<FlowRule>();
        FlowRule rule1 = new FlowRule();
        // 设置资源名称为:methodA
        rule1.setResource(KEY);
        // 设置限流类型:QPS 限流
        rule1.setGrade(RuleConstant.FLOW_GRADE_QPS);
        // 设置 QPS 限流,对应的限制数值
        rule1.setCount(20);
        // 设置 QPS 限流数值满后的应对策略:冷启动,即让通过的流量缓慢增加,直到增加到限制数值上限
        rule1.setControlBehavior(RuleConstant.CONTROL_BEHAVIOR_WARM_UP);
        // 既然设置了冷启动缓慢增长,那么这个缓慢增长到限制数值上限的时间为:10 秒
        rule1.setWarmUpPeriodSec(10);
        // 设置需要限制哪些应用,如果没有想好需要限制谁的话,那么采用 default 方式
        rule1.setLimitApp("default");
        // 将设置好的规则,添加至列表中,并且加载到限流管理器中
        rules.add(rule1);
        FlowRuleManager.loadRules(rules);
        System.out.println("Flow_3_WarmUp rule loaded: " + rules);
    }
    public static void main(String[] args) throws Exception {
        initFlowRule();
        // trigger Sentinel internal init
        Entry entry = null;
        try {
            entry = SphU.entry(KEY);
        } catch (Exception e) {
        } finally {
            if (entry != null) {
                entry.exit();
            }
        }

        Thread timer = new Thread(new TimerTask());
        timer.setName("sentinel-timer-task");
        timer.start();

        //first make the system run on a very low condition
        for (int i = 0; i < 3; i++) {
            // WarmUpTask 控制住了调用资源 methodA 的频率,让系统处于一个低水平调用状态
            Thread t = new Thread(new WarmUpTask());
            t.setName("sentinel-warmup-task");
            t.start();
        }
        Thread.sleep(5000);

        /*
         * Start more thread to simulate more qps. Since we use {@link RuleConstant.CONTROL_BEHAVIOR_WARM_UP} as
         * {@link FlowRule#controlBehavior}, real passed qps will increase to {@link FlowRule#count} in
         * {@link FlowRule#warmUpPeriodSec} seconds.
         */
        for (int i = 0; i < threadCount; i++) {
            // RunTask 稍微加大了调用资源 methodA 的频率,让系统处于一个相对原来处于一个较高水平调用状态
            Thread t = new Thread(new RunTask());
            t.setName("sentinel-run-task");
            t.start();
        }
    }

    static class TimerTask implements Runnable {

        @Override
        public void run() {
            long start = System.currentTimeMillis();
            System.out.println("begin to statistic!!!");
            long oldTotal = 0;
            long oldPass = 0;
            long oldBlock = 0;
            while (!stop) {
                try {
                    TimeUnit.SECONDS.sleep(1);
                } catch (InterruptedException e) {
                }

                long globalTotal = total.get();
                long oneSecondTotal = globalTotal - oldTotal;
                oldTotal = globalTotal;

                long globalPass = pass.get();
                long oneSecondPass = globalPass - oldPass;
                oldPass = globalPass;

                long globalBlock = block.get();
                long oneSecondBlock = globalBlock - oldBlock;
                oldBlock = globalBlock;

                System.out.print("【秒】倒计时: " + seconds + ", ");
                System.out.println((new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS").format(new Date()))
                        + ", 每秒总请求量:" + oneSecondTotal
                        + ", 每秒完成量:" + oneSecondPass
                        + ", 每秒拒绝量:" + oneSecondBlock);
                System.out.println();

                if (seconds-- <= 0) {
                    stop = true;
                }
            }

            long cost = System.currentTimeMillis() - start;
            System.out.println("time cost: " + cost + " ms");
            System.out.println("total:" + total.get() + ", pass:" + pass.get()
                + ", block:" + block.get());
            System.exit(0);
        }
    }

    static class WarmUpTask implements Runnable {
        @Override
        public void run() {
            while (!stop) {
                Entry entry = null;
                try {
                    entry = SphU.entry(KEY);
                    // token acquired, means pass
                    pass.addAndGet(1);
                } catch (BlockException e1) {
                    block.incrementAndGet();
                } catch (Exception e2) {
                    // biz exception
                } finally {
                    total.incrementAndGet();
                    if (entry != null) {
                        entry.exit();
                    }
                }
                Random random2 = new Random();
                try {
                    TimeUnit.MILLISECONDS.sleep(random2.nextInt(2000));
                } catch (InterruptedException e) {
                    // ignore
                }
            }
        }
    }

    static class RunTask implements Runnable {
        @Override
        public void run() {
            while (!stop) {
                Entry entry = null;
                try {
                    entry = SphU.entry(KEY);
                    pass.addAndGet(1);
                } catch (BlockException e1) {
                    block.incrementAndGet();
                } catch (Exception e2) {
                    // biz exception
                } finally {
                    total.incrementAndGet();
                    if (entry != null) {
                        entry.exit();
                    }
                }
                Random random2 = new Random();
                try {
                    TimeUnit.MILLISECONDS.sleep(random2.nextInt(50));
                } catch (InterruptedException e) {
                    // ignore
                }
            }
        }
    }
}
手动降级案例Demo
  • 根据响应时间来限流
    也就是统计慢请求超过一定的比例以后,则在我们设置的时间内停止干活儿,知道下一次请求处理小于我们设置的慢请求的时间,继续干活。
public class Degrade_1_RT_Demo {

    private static final String KEY = "methodA";

    private static volatile boolean stop = false;
    private static int seconds = 120;

    /** 资源 methodA 接收到请求的总数量 **/
    private static AtomicInteger total = new AtomicInteger();
    /** 资源 methodA 被拒绝的数量 **/
    private static AtomicInteger block = new AtomicInteger();
    /** 资源 methodA 真正开始干活时就开始计数,表示 methodA 的任务活跃数 **/
    private static AtomicInteger activeThread = new AtomicInteger();

    private static void initDegradeRule() {
        List<DegradeRule> rules = new ArrayList<>();
        DegradeRule rule = new DegradeRule();

        // 设置资源名称为:methodA
        rule.setResource(KEY);

        // 设置熔断策略:慢调用比例策略
        rule.setGrade(CircuitBreakerStrategy.SLOW_REQUEST_RATIO.getType());

        // 既然策略为慢调用比例,那么设置当请求的响应时间大于 50 毫秒时,则统计为慢调用
        rule.setCount(50);

        // 触发熔断条件 1:最小请求数,若【统计时长】内请求数小于该值时,即使【异常比率】超出 count 阈值也不会熔断
        rule.setMinRequestAmount(10);

        // 触发熔断条件 2:所谓的【统计时长】是多少,即到底在多少时间内进行统计计数
        rule.setStatIntervalMs(8000);
        // 触发熔断条件 3:所谓的【异常比率】其实就是一个 0 到 1 之间的数值,异常数 = minRequestAmount * slowRatioThreshold
        rule.setSlowRatioThreshold(0.2);
        // 当熔断触发后,熔断时长(10 秒)内请求会自动被熔断
        // 经过熔断时长后,若接下来的一个请求响应时间小于 RT 则结束熔断
        rule.setTimeWindow(10);
        // 将设置好的规则,添加至列表中,并且加载到熔断降级管理器中
        rules.add(rule);
        DegradeRuleManager.loadRules(rules);
        System.out.println("Degrade rule loaded: " + rules);
    }
    public static void main(String[] args) throws Exception {
        initDegradeRule();
        registerStateChangeObserver();
        startTick();

        int concurrency = 8;
        for (int i = 0; i < concurrency; i++) {
            Thread entryThread = new Thread(new DegradeRTTask());
            entryThread.setName("sentinel-simulate-traffic-task-" + i);
            entryThread.start();
        }
    }
    private static void registerStateChangeObserver() {
        EventObserverRegistry.getInstance().addStateChangeObserver("logging",
            (prevState, newState, rule, snapshotValue) -> {
                if (newState == State.OPEN) {
                    System.err.println(String.format("%s -> OPEN at %d, snapshotValue=%.2f", prevState.name(),
                        TimeUtil.currentTimeMillis(), snapshotValue));
                } else {
                    System.err.println(String.format("%s -> %s at %d", prevState.name(), newState.name(),
                        TimeUtil.currentTimeMillis()));
                }
            });
    }
    private static void sleep(int timeMs) {
        try {
            TimeUnit.MILLISECONDS.sleep(timeMs);
        } catch (InterruptedException e) {
            // ignore
        }
    }

    private static void startTick() {
        Thread timer = new Thread(new TimerTask());
        timer.setName("sentinel-timer-tick-task");
        timer.start();
    }

    static class TimerTask implements Runnable {
        @Override
        public void run() {
            long start = System.currentTimeMillis();
            System.out.println("Begin to run! Go go go!");
            System.out.println("See corresponding metrics.log for accurate statistic data");

            long oldTotal = 0;
            long oldActivePass = 0;
            long oldBlock = 0;

            while (!stop) {
                sleep(1000);

                long globalTotal = total.get();
                long oneSecondTotal = globalTotal - oldTotal;
                oldTotal = globalTotal;

                long currActivePass = activeThread.get();
                long oneSecondPass = currActivePass - oldActivePass;
                oldActivePass = currActivePass;

                long globalBlock = block.get();
                long oneSecondBlock = globalBlock - oldBlock;
                oldBlock = globalBlock;

                System.out.print("【秒】倒计时: " + seconds + ", ");
                System.out.println((new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS").format(new Date()))
                        + ", 每秒总请求量:" + oneSecondTotal
                        + ", 每秒活跃量:" + oneSecondPass
                        + ", 每秒拒绝量:" + oneSecondBlock);
                if (seconds-- <= 0) {
                    stop = true;
                }
            }

            long cost = System.currentTimeMillis() - start;
            System.out.println("time cost: " + cost + " ms");
            System.out.println("total: " + total.get() + ", pass:" + activeThread.get()
                + ", block:" + block.get());
            System.exit(0);
        }
    }

    static class DegradeRTTask implements Runnable {

        @Override
        public void run() {
            while (true) {
                Entry entry = null;
                try {
                    entry = SphU.entry(KEY);
                    activeThread.incrementAndGet();
                    // RT: [40ms, 80ms)
                    sleep(ThreadLocalRandom.current().nextInt(40, 80));
                } catch (BlockException e) {
                    block.incrementAndGet();
                    sleep(ThreadLocalRandom.current().nextInt(5, 10));
                } finally {
                    total.incrementAndGet();
                    if (entry != null) {
                        entry.exit();
                    }
                }
            }
        }
    }
}
  • 异常比例
    也就是异常超过我们预设的比例,接下来我们设置的时间内都不干活,知道我们后面成功处理了一个请求接着干活。
public class Degrade_2_ExceptionRatio_Demo {

    private static final String KEY = "methodA";

    private static AtomicInteger total = new AtomicInteger();
    private static AtomicInteger pass = new AtomicInteger();
    private static AtomicInteger block = new AtomicInteger();
    private static AtomicInteger bizException = new AtomicInteger();

    private static volatile boolean stop = false;
    private static int seconds = 120;

    private static void initDegradeRule() {
        List<DegradeRule> rules = new ArrayList<>();
        DegradeRule rule = new DegradeRule();

        // 设置资源名称为:methodA
        rule.setResource(KEY);

        // 设置熔断策略:异常比例策略
        rule.setGrade(CircuitBreakerStrategy.ERROR_RATIO.getType());

        // 既然策略为异常比例,出现业务异常则统计异常数量,当异常比例大于 50% 时,则触发熔断
        rule.setCount(0.5d);

        // 触发熔断条件 1:最小请求数,若【统计时长】内请求数小于该值时,即使【异常比例】超出 count 阈值也不会熔断
        rule.setMinRequestAmount(10);

        // 触发熔断条件 2:所谓的【统计时长】是多少,即到底在多少时间内进行统计计数
        rule.setStatIntervalMs(10000);

        // 当熔断触发后,熔断时长(10 秒)内请求会自动被熔断
        // 经过熔断时长后,若接下来的一个请求成功返回,则结束熔断
        rule.setTimeWindow(10);

        // 将设置好的规则,添加至列表中,并且加载到熔断降级管理器中
        rules.add(rule);
        DegradeRuleManager.loadRules(rules);
        System.out.println("Degrade rule loaded: " + rules);
    }

    public static void main(String[] args) throws Exception {
        initDegradeRule();
        registerStateChangeObserver();
        startTick();

        final int concurrency = 8;
        for (int i = 0; i < concurrency; i++) {
            Thread entryThread = new Thread(new DegradeErrorRatioTask());
            entryThread.setName("sentinel-simulate-traffic-task-" + i);
            entryThread.start();
        }
    }

    private static void registerStateChangeObserver() {
        EventObserverRegistry.getInstance().addStateChangeObserver("logging",
            (prevState, newState, rule, snapshotValue) -> {
                if (newState == State.OPEN) {
                    System.err.println(String.format("%s -> OPEN at %d, snapshotValue=%.2f", prevState.name(),
                        TimeUtil.currentTimeMillis(), snapshotValue));
                } else {
                    System.err.println(String.format("%s -> %s at %d", prevState.name(), newState.name(),
                        TimeUtil.currentTimeMillis()));
                }
            });
    }


    private static void sleep(int timeMs) {
        try {
            TimeUnit.MILLISECONDS.sleep(timeMs);
        } catch (InterruptedException e) {
            // ignore
        }
    }

    private static void startTick() {
        Thread timer = new Thread(new TimerTask());
        timer.setName("sentinel-timer-tick-task");
        timer.start();
    }

    static class TimerTask implements Runnable {
        @Override
        public void run() {
            long start = System.currentTimeMillis();
            System.out.println("Begin to run! Go go go!");
            System.out.println("See corresponding metrics.log for accurate statistic data");

            long oldTotal = 0;
            long oldPass = 0;
            long oldBlock = 0;
            long oldBizException = 0;
            while (!stop) {
                sleep(1000);

                long globalTotal = total.get();
                long oneSecondTotal = globalTotal - oldTotal;
                oldTotal = globalTotal;

                long globalPass = pass.get();
                long oneSecondPass = globalPass - oldPass;
                oldPass = globalPass;

                long globalBlock = block.get();
                long oneSecondBlock = globalBlock - oldBlock;
                oldBlock = globalBlock;

                long globalBizException = bizException.get();
                long oneSecondBizException = globalBizException - oldBizException;
                oldBizException = globalBizException;

//                System.out.println(TimeUtil.currentTimeMillis() + ", oneSecondTotal:" + oneSecondTotal
//                    + ", oneSecondPass:" + oneSecondPass
//                    + ", oneSecondBlock:" + oneSecondBlock
//                    + ", oneSecondBizException:" + oneSecondBizException);


                System.out.print("【秒】倒计时: " + seconds + ", ");
                System.out.println((new SimpleDateFormat("yyyy-MM-dd HH:mm:ss.SSSSSS").format(new Date()))
                        + ", 每秒总请求量:" + oneSecondTotal
                        + ", 每秒完成量:" + oneSecondPass
                        + ", 每秒拒绝量:" + oneSecondBlock
                        + ", 每秒业务异常量:" + oneSecondBizException);

                if (seconds-- <= 0) {
                    stop = true;
                }
            }
            long cost = System.currentTimeMillis() - start;
            System.out.println("time cost: " + cost + " ms");
            System.out.println("total: " + total.get() + ", pass:" + pass.get()
                + ", block:" + block.get() + ", bizException:" + bizException.get());
            System.exit(0);
        }
    }

    static class DegradeErrorRatioTask implements Runnable {

        @Override
        public void run() {
            while (true) {
                Entry entry = null;
                try {
                    entry = SphU.entry(KEY);
                    sleep(ThreadLocalRandom.current().nextInt(5, 10));
                    pass.addAndGet(1);

                    // Error probability is 45%
                    if (ThreadLocalRandom.current().nextInt(0, 100) > 55) {
                        // biz code raise an exception.
                        throw new RuntimeException("oops");
                    }
                } catch (BlockException e) {
                    block.addAndGet(1);
                    sleep(ThreadLocalRandom.current().nextInt(5, 10));
                } catch (Throwable t) {
                    bizException.incrementAndGet();
                    // It's required to record exception here manually.
                    Tracer.traceEntry(t, entry);
                } finally {
                    total.addAndGet(1);
                    if (entry != null) {
                        entry.exit();
                    }
                }
            }
        }
    }
}
直接使用框架

在这里插入图片描述

下载jar以后可以创建一个命令启动文件:startup.cmd

java -Dserver.port=9999 -Dcsp.sentinel.dashboard.server=localhost:9999 -Dproject.name=sentinel-dashboard -jar sentinel-dashboard.jar

然后有这样一个控制台:
在这里插入图片描述

  • Sentinel 服务端
    父POM
 <dependencyManagement>
        <dependencies>
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-alibaba-dependencies</artifactId>
                <version>${com.alibaba.cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <dependency>
                <groupId>org.springframework.cloud</groupId>
                <artifactId>spring-cloud-dependencies</artifactId>
                <version>${com.cloud.version}</version>
                <type>pom</type>
                <scope>import</scope>
            </dependency>
            <!-- https://mvnrepository.com/artifact/com.alibaba.cloud/spring-cloud-starter-dubbo -->
            <dependency>
                <groupId>com.alibaba.cloud</groupId>
                <artifactId>spring-cloud-starter-dubbo</artifactId>
                <version>${com.dubbo.version}</version>
            </dependency>
        </dependencies>

    </dependencyManagement>

工程POM

<dependency>
    <groupId>com.alibaba.cloud</groupId>
    <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
</dependency>
<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-web</artifactId>
</dependency>

在这里插入图片描述
在这里插入图片描述

在这里插入图片描述

接入Nacos

在这里插入图片描述

工程pom

 <dependency>
         <groupId>com.alibaba.cloud</groupId>
         <artifactId>spring-cloud-starter-alibaba-sentinel</artifactId>
     </dependency>
     <dependency>
         <groupId>com.alibaba.cloud</groupId>
         <artifactId>spring-cloud-starter-alibaba-nacos-config</artifactId>
     </dependency>
     <dependency>
         <groupId>com.alibaba.cloud</groupId>
         <artifactId>spring-cloud-starter-alibaba-nacos-discovery</artifactId>
     </dependency>
     <dependency>
         <groupId>org.springframework.boot</groupId>
         <artifactId>spring-boot-starter-web</artifactId>
     </dependency>
     <dependency>
         <groupId>com.alibaba.csp</groupId>
         <artifactId>sentinel-datasource-nacos</artifactId>
     </dependency>
spring:
  application:
    name: sentinel-online-flowdeg-consumer
  cloud:
    nacos:
      discovery:
        server-addr: 111.229.199.181:8848
    sentinel:
      transport:
        port: 8719
        dashboard: 127.0.0.1:9999
      datasource:
        r1:
          nacos:
            # nacos地址
            server-addr: 111.229.199.181:8848
            # nacos中配置文件的data-id
            data-id: sentinel-online-flowdeg-consumer
            # nacos 分组
            group-id: DEFAULT_GROUP
            data-type: json
            # 规则类型 流控
            rule-type: flow
            namespace: 05b6571e-7791-4af9-9522-f8097beac3d7

server:
  port: 9064

nacos 配置

[
    {
        "limitApp": "default",
        "resource": "/echo/{string}",
        "grade": 1,
        "count": 20,
        "strategy": 0,
        "refResource": null,
        "controlBehavior": 0,
        "warmUpPeriodSec": null,
        "maxQueueingTimeMs": null,
        "clusterMode": false,
        "clusterConfig":
        {
            "flowId": null,
            "thresholdType": 0,
            "fallbackToLocalWhenFail": true,
            "strategy": 0,
            "sampleCount": 10,
            "windowIntervalMs": 1000,
            "resourceTimeout": 2000,
            "resourceTimeoutStrategy": 0,
            "acquireRefuseStrategy": 0,
            "clientOfflineTime": 2000
        },
        "gmtCreate": "2024-01-05T06:03:30.663+00:00",
        "gmtModified": "2024-01-05T06:03:30.663+00:00"
    }
]

在这里插入图片描述

Nacos Sentinel持久化

在这里插入图片描述

触发一次 Http 请求调用后,发现进入了 com.alibaba.csp.sentinel.init.InitExecutor#doInit 断点

循环逻辑代码块分析

for (InitFunc initFunc : loader) {
	RecordLog.info("[InitExecutor] Found init func: " + initFunc.getClass().getCanonicalName());
	insertSorted(initList, initFunc);
}
for (OrderWrapper w : initList) {
    w.func.init();
    RecordLog.info(String.format("[InitExecutor] Executing %s with order %d",
                                 w.func.getClass().getCanonicalName(), w.order));
}

寻找到了 com.alibaba.csp.sentinel.transport.command.SimpleHttpCommandCenter#start 的相关收发数据逻辑

关键代码 1:开启服务端层面的线程


socketReference = serverSocket;
executor.submit(new ServerThread(serverSocket));
success = true;
port = serverSocket.getLocalPort();

关键代码 2:从 ServerSocket 的 accept 方法收数据

socket = this.serverSocket.accept();
setSocketSoTimeout(socket);
HttpEventTask eventTask = new HttpEventTask(socket);
bizExecutor.submit(eventTask);

数据源处理核心代码

if (FLOW_RULE_TYPE.equalsIgnoreCase(type)) {
    List<FlowRule> flowRules = JSONArray.parseArray(data, FlowRule.class);
    FlowRuleManager.loadRules(flowRules);
    if (!writeToDataSource(getFlowDataSource(), flowRules)) {
        result = WRITE_DS_FAILURE_MSG;
    }
    return CommandResponse.ofSuccess(result);
}
基于上面的源码分析

我们写下面两个类,来完成限流配置的持久化。

@Configuration
public class NacosLinkSentinelConfig implements InitializingBean {

    @Override
    public void afterPropertiesSet() throws Exception {
    }

    @PostConstruct
    public void init() throws Exception {
        NacosWritableDataSource ds = new NacosWritableDataSource(
                "sentinel-nacos-persist-consumer-flow.json",
                "DEFAULT_GROUP",
                "ip",

                "05b6571e-7791-4af9-9522-f8097beac3d7"
        );

        WritableDataSourceRegistry.registerFlowDataSource(ds);
    }
}

public class NacosWritableDataSource<T> implements WritableDataSource<T> {

    private String dataId;
    private String group;
    private ConfigService configService;

    public NacosWritableDataSource(String dataId,
                                   String group,
                                   String serverAddr,
                                   String namespace) throws Exception {
        this.dataId = dataId;
        this.group = group;

        Properties properties = new Properties();
        properties.setProperty(PropertyKeyConst.SERVER_ADDR, serverAddr);
        properties.setProperty(PropertyKeyConst.NAMESPACE, namespace);
        properties.setProperty(PropertyKeyConst.USERNAME, "nacos");
        properties.setProperty(PropertyKeyConst.PASSWORD, "nacos");
        configService = NacosFactory.createConfigService(properties);
    }

    @Override
    public void write(T t) throws Exception {
        configService.publishConfig(this.dataId, this.group, JSON.toJSONString(t),  "json");
    }

    @Override
    public void close() throws Exception {
    }
}

这样我们在界面修改就可以持久化到nacos,这里要注意如果在nacos直接修改,控制台上是不能感知到的。
在这里插入图片描述
下次重启控制台,Nacos被持久化规则也会进行加载:
在这里插入图片描述

原文地址:https://blog.csdn.net/qq_43259860/article/details/135385265

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