Spring @Scheduled annotation random delay

spring spring-annotations spring-scheduled
masstroy picture masstroy · Jan 9, 2015 · Viewed 9.4k times · Source

I am using the @Scheduled annotation from Spring framework to invoke a method. But I have multiple nodes in my setup and I do not want them to all run at exactly the same time. So I'd like to set a random value to the initial delay to offset them from each other.

import org.springframework.scheduling.annotation.Scheduled;

@Scheduled(fixedRate = 600000, initialDelay = <random number between 0 and 10 minutes> )

Unfortunately, I am only allowed to use a constant expression here. Is there any other way around this? I thought of using Spring expression language.

Answer

mekazu picture mekazu · Jul 12, 2016

To make the initial delay randomly somewhere between 0 and the fixedRate try this:

@Scheduled(fixedDelayString = "${some.delay}", initialDelayString = "${random.int(${some.delay})}")

Where you define some.delay (but pick a more suitable name) as 10 minutes as a property like so in your application.properties or equivalent.

some.delay = 600000

Of course if you want to be lazy and hard code it you can always just use ${random.int(600000)}

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