👀 Views: 178 💬 Answers: 1 📅 Created: 2025-07-31

scala akka-stream kafka Scala

I'm following best practices but I'm optimizing some code but I've looked through the documentation and I'm still confused about I'm currently working on a data processing application using Akka Streams in Scala 2.13... I have a source that reads data from a Kafka topic and processes it through a flow that performs some transformations. However, I've noticed that under certain load conditions, my stream seems to terminate unexpectedly, and I receive the following error message: `Stream has been terminated due to an upstream error`. I've checked the logs, and it appears that the termination is not due to an exception in my processing logic but rather related to backpressure handling. Here’s a simplified version of my stream setup: ```scala import akka.actor.ActorSystem import akka.kafka.scaladsl.Consumer import akka.kafka.{ConsumerSettings, Subscriptions} import akka.stream.scaladsl.{Flow, Keep, Sink, Source} import akka.stream.{Materializer, OverflowStrategy} import org.apache.kafka.common.serialization.StringDeserializer implicit val system = ActorSystem("example-system") implicit val materializer = Materializer(system) val consumerSettings = ConsumerSettings(system, new StringDeserializer, new StringDeserializer) .withBootstrapServers("localhost:9092") .withGroupId("group1") .withProperty("auto.offset.reset", "earliest") val source = Consumer.plainSource(consumerSettings, Subscriptions.topics("my-topic")) val flow = Flow[String].map { msg => // Simulate some processing Thread.sleep(100) msg.toUpperCase } val sink = Sink.foreach[String](println) source.via(flow).toMat(sink)(Keep.both).run() Is there a better approach? Any help would be greatly appreciated! I've been using Scala for about a year now. What am I doing wrong?