Batch processing and functional programming

Question

As a Java developer, I'm used to use Spring Batch for batch processing, generally using a streaming library to export large XML files with StAX for exemple.

I'm now developping a Scala application, and wonder if there's any framework, tool or guideline to achieve batch processing.

My Scala application uses the Cake Pattern and I'm not sure how I could integrate this with SpringBatch. Also, I'd like to follow the guidelines described in Functional programming in Scala and try to keep functional purity, using stuff like the IO monad...

I know this is kind of an open question, but I never read anything about this...

Has anyone already achieved functional batch processing here? How was it working? Am I supposed to have a main that creates a batch processing operation in an IO monad and run it? Is there any tool or guideline to help, monitor or handle restartability, like we use Spring Batch in Java. Do you use Spring Batch in Scala? How do you handle the integration part, for exemple waiting for a JMS/AMQP message to start the treatment that produces an XML?

Any feedback on the subjet is welcome

Answer 1

You don't mention what kind of app you are developing with Scala, so I'm going to wild guess here and suppose you are doing a server side one. Going further with wild guessing let's say you are using Akka... because you are using it, aren't you? :)

In that case, I guess what you are looking for is Akka Quartz Scheduler, the official Quartz Extension and utilities for cron-style scheduling in Akka. I haven't tried it myself, but from your requirements it seems that Akka + this module would be a good fit. Take into account that Akka already provides hooks to handle restartability of failed actors, and I don't think that it would be that difficult to add monitoring of batch processes leveraging the lifecycle callbacks built into actors.

Regarding interaction with JMS/AMQP messaging, you could use the Akka Camel module, that provides support for sending and receiving messages through a lot of protocols, including JMS. Using this module you could have a consumer actor receiving messages from some JMS endpoint, and fire whatever process you want from there, probably forwarding or sending a new message to the actor responsible for that process. If the process is fired either by a cron style timer or an incoming message you can reuse the same actor to accomplish the task.