Sentinel源码分析

StatisticSlot#entry()node.addPassRequest(count);

StatisticSlot#entry()catch (BlockException e) {              node.increaseBlockQps(count);

StatisticNode#addPassRequest() rollingCounterInSecond.addPass(count);

分析结束

Y

MetricBucket#add()counters[event.ordinal()].add(n); return this;

LeapArray#calculateTimeIdx()long timeId = timeMillis / windowLengthInMs;return (int)(timeId % array.length());

<dependency>          <groupId>com.alibaba.cloud</groupId>          <artifactId>spring-cloud-starter-alibab-sentinel</artifactId> </dependency>

                                            CtSph#entryWithPriority()//查找slotchainProcessorSlot<Object> chain = lookProcessChain(resourceWrapper);

DefaultNode#addPassRequest()super.addPassRequest(count);

前面已分析

DefaultNode#increaseThreadNum()super.increaseThreadNum();

滑动时间窗算法

LeapArray#currentWindow()calculateWindowStart(timeMillis);

ArrayMetric#addPass()WindowWrap<MetricBucket> wrap = data.currentWindow();

该方法会将槽链中后续所有slot槽节点执行完毕，然后才会返回到该方法语句后继续执行，将该请求添加到统计数据中。不过，在后续槽点执行过程中，可能会抛出各种异常，而这些异常会在该slot中被捕获，然后将该异常添加到统计数据中。下面将详细分析FlowSlot与DegradeSlot

SentinelAutoConfiguration#SentinelResourceAspectnew SentinelResourceAspect()

FlowRuleChecker#checkFlow()ruleProvider.apply(resource.getName());

AbstractCircuitBreaker#retryTimeoutArrived()TimeUtil.currentTimeMillis() >= nextRetryTimestamp;

AbstractCircuitBreaker#fromOpenToHalfOpen()//通过CAS将状态由open修改为half_open，修改成功，则返回true，否则返回false

LeapArray#currentWindow()calculateTimeIdx(timeMillis)

LongAdder#increment()  add(1L); 

StatisticNode#increaseThreadNum()curThreadNum.increment();

通过SPI加载以下三个模块中com.alibaba.csp.sentinel.slotchain.ProcessorSlot文件的9个Slot* sentinel-core* sentinel-adapter#sentinel-api-gateway-adapter-common* sentinel-extension#sentinel-paramter-flow-control

    SlotChainProvider#newSlotChain()slotChainBuilder.build()

Anonymous in ruleProvier in FlowSlot#apply

LeapArray#currentWindow()WindowWrap<MetricBucket> wrap = data.currentWindow();

ArrayMetric#addPass()wrap.value().addPass(count);

DegradeSlot#performChecking()cb.tryPass(context);

StatisticSlot#entry()node.increaseThreadNum();

                                            CtSph#lookProcessChain()SlotChainProvider.newSlotChain()

AbstractCircuitBreaker#tryPass()fromOpenToHalfOpen(context)

                                            SentinelResourceAspect#@Around(\"sentinelResourceAnnotationPointcut()\")public Object invokeResourceWithSentinel(ProceedingJoinPoint pjp) throws Throwable 

DefaultSlotChainBuilder#build()将SPI加载的所有Slot通过以下方法逐个添加到SlotChainchain.addLast((AbstractLinkedProcessorSlot<?>) slot);

开始

BucketLeapArray#resetWindowTo()//更新窗口起始时间w.resetTo(startTime);//将多维度统计数据清零w.value().reset();return w;

canPass()方法是，设置不同的流控效果，会执行不同的controller的实现。* DefaultController ：快速失败* RateLimiterController：排队等待* WarmUpController：warm up* WarmUpRateLimiterController：warm up+排队等待

sentinel滑动时间算法源码解析

AbstractCircuitBreaker#tryPass()retryTimeoutArrived();

LeapArray#calculateWindowStart()timeMillis - timeMillis % windowLengthInMs;

spring.factories

StatisticSlot#entry()catch (PriorityWaitException ex) { node.increaseThreadNum();

                                            通过SPI加载sentinel-core模块中com.alibaba.csp.sentinel.slotchain.SlotChainBuilder文件的DefaultSlotChainBuilder

windowStart > old.windowStart()