tencentcloud-edgeone-migration-nodejs-v2
Version:
tencentcloud cdn config copy to edgeone
162 lines • 6.05 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.PolarisCircuitBreaker = void 0;
const plugins_1 = require("../../plugins");
const utils_1 = require("../../utils");
const kDefaultOptions = {
/**
* 连续失败统计周期
*/
continuousWindow: 1 * utils_1.kMinutes,
/**
* 连续失败次数阈值
*/
continuousErrors: 10,
/**
* 触发熔断的最低请求阈值
*/
fuseThreshold: 10,
/**
* 熔断错误率阈值
*/
fuseRate: 0.5,
/**
* 半开恢复 `HalfClose` ---> `Normal` 所需的最小成功请求数
* 值不能大于探活任务的最大探测次数
*/
halfClose2Normal: 2,
/**
* 半开熔断 `HalfClose` ---> `Fused` 所需的最小失败请求数
* 值不能大于探活任务的最大探测次数
*/
halfClose2Fused: 2
};
class PolarisCircuitBreaker {
// #endregion
constructor(options) {
this.type = plugins_1.PluginType.CircuitBreaker;
this.name = "PolarisCircuitBreaker";
this.disposed = false;
this.periodStat = new WeakMap();
// #region realtime
this.realtimeStat = new WeakMap();
this.timer = null;
this.options = Object.assign(Object.assign({}, kDefaultOptions), options);
}
// #region dispose
dispose() {
if (this.timer) {
clearTimeout(this.timer);
this.timer = null;
}
this.disposed = true;
}
get isDisposed() {
return this.disposed;
}
// #endregion
period(namespace, service, instances, stat) {
const changeList = new Map();
stat.summaryStat.forEach((computed, instance) => {
let errCalls = 0;
let succCalls = 0;
computed.forEach(({ count }, { success }) => {
if (success) {
succCalls += count;
}
else {
errCalls += count;
}
});
switch (instance.status) {
case 0 /* Normal */: {
const rspCalls = errCalls + succCalls;
if (rspCalls > this.options.fuseThreshold) {
/*
* 为防止用户漏报了调用结果导致计算的成功率为 0，
* 使用 `1 - errRate(k)` 作为成功率。
*/
const succRate = 1 - (errCalls / rspCalls);
if (succRate <= this.options.fuseRate) {
/** `Normal` ---> `Fused` */
changeList.set(instance, {
status: 3 /* Fused */,
reason: `[${this.name}] [period], succRate(${succRate}) <= fuseRate(${this.options.fuseRate})`
});
}
}
break;
}
case 2 /* HalfClose */: {
let callStat = this.periodStat.get(instance);
if (!callStat) {
callStat = {
succCalls,
errCalls
};
this.periodStat.set(instance, callStat);
}
else {
callStat.succCalls += succCalls;
callStat.errCalls += errCalls;
}
if (callStat.succCalls >= this.options.halfClose2Normal) {
/** `HalfClose` ---> `Normal` */
changeList.set(instance, {
status: 0 /* Normal */,
reason: `[${this.name}] [period], succCalls(${callStat.succCalls}) >= halfClose2Normal(${this.options.halfClose2Normal})`
});
this.periodStat.delete(instance);
}
else if (callStat.errCalls >= this.options.halfClose2Fused) {
/** `HalfClose` ---> `Fused` */
changeList.set(instance, {
status: 3 /* Fused */,
reason: `[${this.name}] [period], errCalls(${callStat.errCalls}) >= halfClose2Fused(${this.options.halfClose2Fused})`
});
this.periodStat.delete(instance);
}
break;
}
case 1 /* HalfOpen */: {
break;
}
case 3 /* Fused */: // [[fallthrough]]
default: {
(0, utils_1.UNREACHABLE)();
}
}
});
return changeList;
}
realtime(namespace, service, instance, success) {
/**
* 为了性能考虑所有实时熔断流程采用同一定时器驱动
* tradeoff: 第一个统计周期中的统计数据可能是不精确的。
*/
if (!this.timer) {
this.timer = setTimeout(() => {
this.realtimeStat = new WeakMap();
this.timer = null;
}, this.options.continuousWindow).unref();
}
let count = this.realtimeStat.get(instance);
if (success) {
if (count !== undefined) {
this.realtimeStat.delete(instance);
}
return;
}
count = (count || 0) + 1;
if (count >= this.options.continuousErrors) {
this.realtimeStat.delete(instance);
return {
status: 3 /* Fused */,
reason: `[${this.name}] [realtime], found ${count} times failed >= continuousErrors(${this.options.continuousErrors})`
};
}
this.realtimeStat.set(instance, count);
}
}
exports.PolarisCircuitBreaker = PolarisCircuitBreaker;
//# sourceMappingURL=polaris.js.map