What's the best way to build a queue for long-running jobs in a Grails app?

Question

I have a Grails app that has some computationally intensive optimizations with a running time of ~5 minutes (perhaps more). Currently, I'm doing these in the main request thread, i.e. it takes 5 minutes for the request to return. It works, but is of course horrible from a usability perspective.

So what's the best way to implement this in an asynchronous way? I assume a ThreadPoolExecutor would have to be involved, but how do I start and access it? Can I model it as a Grails Service? Or a Job (seems that those are only meant for recurring jobs though)?

Also, what's the best way to handle job status? Via a a flag or perhaps an entire new class in the DB? Have the browser show a spinner and keep polling until the status changes?

Answer 1

There is a grails plugin background-thread which might be just what you are looking for.

Of course it would be possible to roll your own thread pooling or use existing Java stuff.

Answer 2

I'd use the grails JMS Plugin for this.

Then you can create a service with an "onMessage" method that interacts automatically with an underlying jms provider (like OpenMQ or ActiveMQ.

It makes this kind of thing pretty easy.

Answer 3

Background-thread plugin is outdated so I wouldn't recommend using it and also the JMS seems overkill for background processing. JMS is more of a message queue rather than background processing utility.

I would recommend either using Quartz plugin or using the gpars.