Java：防止在多个实例上创建相同的任务

Question

I'm in the middle of creating some Data Processor. It has next API method: create some task, get task result.

Data Processors should recover if fail and allowed to be run in multiple instances. (DP1, DP2, etc).

I store the state in Redis db. For example:

API creates task (Runnable), put it into the scheduledThreadPoolExecutor, and run it every 5 seconds, modifying Redis state. After getting the results of tasks, task is cancelled and Redis state is erased.

If DataProcessor fails and restart, I get the state from the Redis Database, re-create tasks and everything is OK.

But if another DataProcessor instance is run, it also takes state from Redis, re-create tasks and runs them, which is not preferred, as these tasks are already processed by another instance of DataProcessor.

I can't even mark this Redis state as [not processed anymore] in case of fail, because the instance which knows that it failed is.. well, failed and can't do anything anymore.

What can be done in this situation?

Answer 1

找到“ Redisson”库，它具有分布式调度程序，正是我需要的。