Akka Http: Exceeded configured max-open-requests value of [32]

Question

I post some data to Server using the following code

  def post(endpoint: String, entity: Strict) = {
    Http().singleRequest(HttpRequest(uri = Notifier.notificationUrl + endpoint, method = HttpMethods.POST,
      entity = entity)) onComplete {
      case Success(response) => response match {
        case HttpResponse(StatusCodes.OK, _, _, _) =>
          log.info("communicated successfully with Server")
      }
      case Failure(response) =>
        log.error("communicated failed with Server: {}", response)
    }
  }

This is called every 10 seconds when Notifier actor receives message as following

case ecMonitorInformation: ECMonitorInformation =>
  post("monitor", httpEntityFromJson(ecMonitorInformation.toJson))

Problem?

I see that Initially (around 5 requests going to server) but then it hungs up, I do not see any logging, server does not receive any data. After a while on the client side, I see following

ERROR c.s.e.notification.Notifier - communicated failed with Server: java.lang.RuntimeException: Exceeded configured max-open-requests value of [32]

What is going on? How do I fix this issue?

Answer 1

If you are going to be repeatedly calling your method, you might want to consider using one of the connection pool based client methods as described here: http://doc.akka.io/docs/akka-stream-and-http-experimental/1.0/scala/http/client-side/index.html

You can also set the connection pool settings in the akka-http client configuration: http://doc.akka.io/docs/akka-stream-and-http-experimental/1.0/scala/http/configuration.html#akka-http-core

Search for host-connection-pool.