Stream completes after adding flow

Question

I have a simple stream declared like following:

Source.tick(Duration.ofSeconds(1), Duration.ofSeconds(30), Files.list(rootDir).collect(Collectors.toList()))
                .mapConcat(files -> files)
                .log("scanning logs")
                .via(logsFlow.create())
                .via(kafkaFlow.create())
//                .via(archiveFlow.create())
                .runWith(Sink.ignore(), materializer)
                .whenComplete((a, b) -> {
                    log.info("done");
                });

With archiveFlow commented out everything works like expected. But when I'm adding additional flow no matter if it is archive flow or some simple flow like this:

.via(Flow.of(Path.class).map(path -> {
                    log.info("foo");
                    return path;
                }))

stream is completed after first tick. Why is that?

2019-03-20 21:35:09.292 DEBUG 50089 --- [lt-dispatcher-2] a.kafka.internal.DefaultProducerStage    : Stage completed
2019-03-20 21:35:09.294 DEBUG 50089 --- [lt-dispatcher-4] akka.stream.Materializer                 : [scanning logs] Downstream finished.
2019-03-20 21:35:09.296  INFO 50089 --- [onPool-worker-3] com.example.MyStream  : done

score 0 · Answer 1 · answered Mar 25 '19 at 13:43

0

It turned out that there was an error swallowed by Akka. I used Supervision strategy and now everything works fine.

answered Mar 25 '19 at 13:43

Piotr Kozlowski

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1

it's a good practice always to use `recover` for flow - https://doc.akka.io/docs/akka/2.5.5/scala/stream/stream-error.html – Serhii Shynkarenko Mar 27 '19 at 03:17

Stream completes after adding flow

1 Answers1