背景
Apache DolphinScheduler 定时任务配置采用的 7 位 Crontab 表达式，分别对应秒、分、时、月天、月、周天、年。
在团队日常开发工作中，工作流的定时调度一般不会细化到秒级别。但历史上出现过因配置的疏忽大意而产生故障时间，如应该配置每分钟执行的工作流被配置长了每秒执行，造成短时间内产生大量工作流实例，对 Apache DolphinScheduler 服务可用性和提交任务的 Hadoop 集群造成影响。
基于此，团队决定将 DolphinScheduler 中定时任务配置模块的 Crontab 表达式做限制，从平台侧杜绝此类事件发生。
方案
我们的方案是从前后端双方面限制 Crontab 表达式的第一位：
- 前端配置选择不提供"每一秒钟"选项
- 服务端接口判断第一位为 * 时，返回错误
前端修改
在前端项目中，秒、分、时 均为统一模版（CrontabTime），因此新增 dolphinscheduler-ui/src/components/crontab/modules/second.tsx
只保留两种模式：intervalTime 和 specificTime
/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
import _ from 'lodash'
import { defineComponent, onMounted, PropType, ref, toRefs, watch } from 'vue'
import { NInputNumber, NRadio, NRadioGroup, NSelect } from 'naive-ui'
import { useI18n } from 'vue-i18n'
import { ICrontabI18n } from '../types'
import { isStr, specificList } from '../common'
import styles from '../index.module.scss'
const props = {
timeMin: {
type: Number as PropType<number>,
default: 0
},
timeMax: {
type: Number as PropType<number>,
default: 60
},
intervalPerform: {
type: Number as PropType<number>,
default: 5
},
intervalStart: {
type: Number as PropType<number>,
default: 3
},
timeSpecial: {
type: Number as PropType<number | string>,
default: 60
},
timeValue: {
type: String as PropType<string>,
default: '*'
},
timeI18n: {
type: Object as PropType<ICrontabI18n>,
require: true
}
}
export default defineComponent({
name: 'CrontabSecond',
props,
emits: ['update:timeValue'],
setup(props, ctx) {
const options = Array.from({ length: 60 }, (x, i) => ({
label: i.toString(),
value: i
}))
const timeRef = ref()
const radioRef = ref()
const intervalStartRef = ref(props.intervalStart)
const intervalPerformRef = ref(props.intervalPerform)
const specificTimesRef = ref<Array<number>>([])
/**
* Parse parameter value
*/
const analyticalValue = () => {
const $timeVal = props.timeValue
// Interval time
const $interval = isStr($timeVal, '/')
// Specific time
const $specific = isStr($timeVal, ',')
// Positive integer (times)
if (
($timeVal.length === 1 ||
$timeVal.length === 2 ||
$timeVal.length === 4) &&
_.isInteger(parseInt($timeVal))
) {
radioRef.value = 'specificTime'
specificTimesRef.value = [parseInt($timeVal)]
return
}
// Interval times
if ($interval) {
radioRef.value = 'intervalTime'
intervalStartRef.value = parseInt($interval[0])
intervalPerformRef.value = parseInt($interval[1])
timeRef.value = `${intervalStartRef.value}/${intervalPerformRef.value}`
return
}
// Specific times
if ($specific) {
radioRef.value = 'specificTime'
specificTimesRef.value = $specific.map((item) => parseInt(item))
return
}
}
// Interval start time（1）
const onIntervalStart = (value: number | null) => {
intervalStartRef.value = value || 0
if (radioRef.value === 'intervalTime') {
timeRef.value = `${intervalStartRef.value}/${intervalPerformRef.value}`
}
}
// Interval execution time（2）
const onIntervalPerform = (value: number | null) => {
intervalPerformRef.value = value || 0
if (radioRef.value === 'intervalTime') {
timeRef.value = `${intervalStartRef.value}/${intervalPerformRef.value}`
}
}
// Specific time
const onSpecificTimes = (arr: Array<number>) => {
specificTimesRef.value = arr
if (radioRef.value === 'specificTime') {
specificReset()
}
}
// Reset interval time
const intervalReset = () => {
timeRef.value = `${intervalStartRef.value}/${intervalPerformRef.value}`
}
// Reset specific time
const specificReset = () => {
let timeValue = '0'
if (specificTimesRef.value.length) {
timeValue = specificTimesRef.value.join(',')
}
timeRef.value = timeValue
}
const updateRadioTime = (value: string) => {
switch (value) {
case 'intervalTime':
intervalReset()
break
case 'specificTime':
specificReset()
break
}
}
watch(
() => timeRef.value,
() => ctx.emit('update:timeValue', timeRef.value.toString())
)
onMounted(() => analyticalValue())
return {
options,
radioRef,
intervalStartRef,
intervalPerformRef,
specificTimesRef,
updateRadioTime,
onIntervalStart,
onIntervalPerform,
onSpecificTimes,
...toRefs(props)
}
},
render() {
const { t } = useI18n()
return (
<NRadioGroup
v-model:value={this.radioRef}
onUpdateValue={this.updateRadioTime}
>
<div class={styles['crontab-list']}>
<NRadio value={'intervalTime'} />
<div class={styles['crontab-list-item']}>
<div class={styles['item-text']}>{t(this.timeI18n!.every)}</div>
<div class={styles['number-input']}>
<NInputNumber
defaultValue={5}
min={this.timeMin}
max={this.timeMax}
v-model:value={this.intervalPerformRef}
onUpdateValue={this.onIntervalPerform}
/>
</div>
<div class={styles['item-text']}>
{t(this.timeI18n!.timeCarriedOut)}
</div>
<div class={styles['number-input']}>
<NInputNumber
defaultValue={3}
min={this.timeMin}
max={this.timeMax}
v-model:value={this.intervalStartRef}
onUpdateValue={this.onIntervalStart}
/>
</div>
<div class={styles['item-text']}>{t(this.timeI18n!.timeStart)}</div>
</div>
</div>
<div class={styles['crontab-list']}>
<NRadio value={'specificTime'} />
<div class={styles['crontab-list-item']}>
<div>{t(this.timeI18n!.specificTime)}</div>
<div class={styles['select-input']}>
<NSelect
multiple
options={specificList[this.timeSpecial]}
placeholder={t(this.timeI18n!.specificTimeTip)}
v-model:value={this.specificTimesRef}
onUpdateValue={this.onSpecificTimes}
/>
</div>
</div>
</div>
</NRadioGroup>
)
}
})服务端
添加Crontab表达式检验（有两处：一处是新增Post接口、另一处是修改PUT接口），直接添加个检测方法供这两处调用：
if (scheduleParam.getCrontab().startsWith("*")) {
logger.error("The crontab must not start with *");
putMsg(result, Status.CRONTAB_EVERY_SECOND_ERROR);
return result;
}本文完！
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