在集群环境中避免Spring Batch作业中的并发

Question

I want to ensure that a Spring job is not started a second time while it still runs. This would be trivial in a single JVM environment.

However, how can I achieve this in a cluster environment (more specifically, in JBoss 5.1 - I know a bit antiquated; if solutions exist for later versions, I'd be interested in those as well).

So, it should be kind of a Singleton pattern across all cluster nodes.

I am considering using database locks or a message queue. Is there a simpler / better performing solution?

Answer 1

You need to synchronize threads that doesn't know nothing each other, so the easiest way is to share some information on a common place. Valid alternatives are:

• A shared database
• A shared file
• An external web service holding the status of the batch process

If you prefer to use a shared database try to use a database like Redis to improve your performance. It is an in memory database with persistence on disk, so accessing the status of the batch process should be enough fast.

Answer 2

这为时已晚，但是对于将来的查找而言：spring batch使用jpa存储库来同步作业，因此可以避免并发。

Answer 3

You can add a Job Listener and in the before step and use JobExecutionDao in it to find all JobExecutions . If there are more than one running - throw an exception and exit the job.