How to handle nested Future failures gracefully in Scala with Akka?
I've been struggling with this for a few days now and could really use some help. I need some guidance on Quick question that's been bugging me - I've searched everywhere and can't find a clear answer. I'm working on a Scala application that uses Akka alongside Futures for asynchronous processing. I've hit a snag with behavior handling in nested Futures. In my case, I'm making an API call that returns a Future, and if that succeeds, I make another call based on the result. However, if either of these calls fails, I want to handle the behavior gracefully. Here's a simplified version of my code: ```scala import akka.actor.ActorSystem import scala.concurrent.{Future, ExecutionContext} import scala.util.{Failure, Success} implicit val system = ActorSystem() implicit val ec = ExecutionContext.global def apiCall1(): Future[Int] = Future { // Simulating a successful API call 42 } def apiCall2(value: Int): Future[String] = Future { // Simulating an API call that might unexpected result if (value > 0) "Success" else throw new RuntimeException("API call failed") } val result = for { value1 <- apiCall1().recover { case ex: Exception => println(s"behavior during apiCall1: ${ex.getMessage}") -1 } value2 <- apiCall2(value1).recover { case ex: Exception => println(s"behavior during apiCall2: ${ex.getMessage}") "Fallback" } } yield value2 result.onComplete { case Success(res) => println(s"Final result: $res") case Failure(ex) => println(s"Unexpected behavior: ${ex.getMessage}") } ``` The scenario I'm working with is that even though I'm handling errors within the for-comprehension using `recover`, I still get an `Unexpected behavior: ...` message in the completion callback when `apiCall2` fails. It seems like the failure in `apiCall1` does not prevent the execution of `apiCall2`, but any failure in `apiCall2` seems to propagate despite my recovery strategy. I want to ensure that if the first API call fails, no further processing occurs, and I handle the behavior properly. What is the best way to manage this flow to prevent cascading failures here? I'm using Scala 2.13 with Akka 2.6. I'm looking for best practices that can guide to achieve smooth behavior handling in this scenario. I'm working on a CLI tool that needs to handle this. For context: I'm using Scala on Windows. This is part of a larger REST API I'm building. Is there a better approach? Any examples would be super helpful.