Issues with Performance Tuning Akka HTTP Streaming with Backpressure in Scala 2.13.6
I'm sure I'm missing something obvious here, but I'm trying to implement I'm not sure how to approach Does anyone know how to I tried several approaches but none seem to work. I'm currently working on an Akka HTTP application that processes a high volume of streaming data, but I'm facing significant performance issues, especially when it comes to backpressure handling. I have set up a simple streaming route that pulls data from a source and transforms it before sending it to the client. However, under load, I notice that there are times when the server's memory usage spikes, leading to `OutOfMemoryError`.\n\nI followed the Akka Streams documentation and used `Source.queue` to manage backpressure, but the performance is still not ideal. Here's a simplified version of my code:\n\n```scala\nimport akka.actor.ActorSystem\nimport akka.http.scaladsl.Http\nimport akka.http.scaladsl.model.{HttpResponse, StatusCodes}\nimport akka.http.scaladsl.server.Directives._\nimport akka.stream.scaladsl.{Sink, Source}\nimport akka.stream.{ActorMaterializer, OverflowStrategy}\nimport scala.concurrent.duration._\nimport scala.concurrent.Future\n\nimplicit val system = ActorSystem()\nimplicit val materializer = ActorMaterializer()\n\n// This queue simulates incoming data\nval (queue, source) = Source.queue[Int](bufferSize = 100, OverflowStrategy.backpressure).preMaterialize()\n\nval route = path("stream") {\n get {\n complete {\n source.map(data => processData(data)).runWith(Sink.asPublisher(fanout = true))\n }\n }\n} \n\ndef processData(data: Int): String = {\n // Simulate some processing\n Thread.sleep(50) // Simulating delay\n s"Processed: $data"\n} \n\nHttp().bindAndHandle(route, "localhost", 8080)\n```\n\nThe `processData` function simulates some processing delay, but it seems that the backpressure isn't working as expected. The server responds too slowly to incoming requests, and the queue fills up, causing memory bloat. I tried adjusting the buffer size and using different overflow strategies, but nothing seems to help.\n\nCould someone provide insights on optimizing this setup or share best practices for handling performance in Akka HTTP streaming? What are common pitfalls I might be encountering here? Thanks! What am I doing wrong? This issue appeared after updating to Scala 3.10. I'm working with Scala in a Docker container on Windows 11. What would be the recommended way to handle this? For reference, this is a production web app. Could this be a known issue?