春季@计划每天在凌晨4:00 AM和4:30 AM之间的任意分钟开始 [英] Spring @Scheduled to be started every day at a random minute between 4:00AM and 4:30AM

问题描述

如问题标题中所述，我需要设置Spring Scheduler，它将运行方法将每天从数据库中的内容加载到内存中，每天凌晨4点左右

as stated in the title of a question, I need to set Spring Scheduler that will run method to load something from database into memory, every day around 4AM

问题是我有该服务器的多个实例，并且我不希望所有实例都同时开始执行，因为这会降低数据库的速度。所以我希望时间是在凌晨4:00 AM到4:30 AM之间的某个随机时间

The thing is that I have multiple instances of this server and I don't want all to start executing at the same time cause it will slow down the DB. So I want the time to be at a random minute somewhere between 4:00AM and 4:30AM

所以可以说一个实例每天开始于4:03 AM，另一个实例每天开始查询执行持续1分钟。

So lets say one instance will start everyday at 4:03AM, the other at 4:09AM, third at 4:21AM etc. The execution of query lasts for 1 minute.

这可能与cron表达式有关，但不使用$ RANDOM bash（因为我想我没有），或者也许我需要以其他方式将这个随机值注入

Is this possible to do with cron expression, but without using $RANDOM bash (cause I think I dont have it) , or maybe I need to inject this random value some other way into

@Scheduled(cron="* randomMinuteValue 4 * * *")

推荐答案

使用Spring的 RandomValuePropertySource

@Scheduled(cron="0 ${random.int[0,30]} 4 * * ?")

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