Scala console application does not stop when using reactive mongo driver

I am playing with Mongo base via Reactive Mongo driver

import org.slf4j.LoggerFactory

import reactivemongo.api.MongoDriver
import reactivemongo.api.collections.default.BSONCollection
import reactivemongo.bson.BSONDocument

import scala.concurrent.Future
import scala.concurrent.duration._
import scala.concurrent.ExecutionContext.Implicits.global

object Main {

  val log = LoggerFactory.getLogger("Main")

  def main(args: Array[String]): Unit = {

    log.info("Start")

    val conn = new MongoDriver().connection(List("localhost"))
    val db = conn("test")

    log.info("Done")

  }
}

      

        
        
        
      

    

My build.sbt

file:

lazy val root = (project in file(".")).
  settings(
    name := "simpleapp",
    version := "1.0.0",
    scalaVersion := "2.11.4",
    libraryDependencies ++= Seq(
      "org.reactivemongo" %% "reactivemongo" % "0.10.5.0.akka23",
      "ch.qos.logback" % "logback-classic" % "1.1.2"
    )
  )

      

        
        
        
      

    

When I run: sbt compile run

I am getting this output:

$ sbt compile run
[success] Total time: 0 s, completed Apr 25, 2015 5:36:51 PM
[info] Running Main 
ERROR StatusLogger No log4j2 configuration file found. Using default configuration: logging only errors to the console.
17:36:52.328 [run-main-0] INFO  Main - Start
17:36:52.333 [run-main-0] INFO  Main - Done

      

        
        
        
      

    

And the application doesn't stop ....: /

I need to press Ctrl+ Cto kill him

I read what MongoDriver()

creates ActorSystem

, so I tried to close the connection manually with conn.close()

, but I get this:

[info] Running Main 
ERROR StatusLogger No log4j2 configuration file found. Using default configuration: logging only errors to the console.
17:42:23.252 [run-main-0] INFO  Main - Start
17:42:23.258 [run-main-0] INFO  Main - Done
17:42:23.403 [reactivemongo-akka.actor.default-dispatcher-2] ERROR reactivemongo.core.actors.MongoDBSystem - (State: Closing) UNHANDLED MESSAGE: ChannelConnected(-973180998)
[INFO] [04/25/2015 17:42:23.413] [reactivemongo-akka.actor.default-dispatcher-3] [akka://reactivemongo/deadLetters] Message [reactivemongo.core.actors.Closed$] from Actor[akka://reactivemongo/user/$b#-1700211063] to Actor[akka://reactivemongo/deadLetters] was not delivered. [1] dead letters encountered. This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'.
[INFO] [04/25/2015 17:42:23.414] [reactivemongo-akka.actor.default-dispatcher-3] [akka://reactivemongo/user/$a] Message [reactivemongo.core.actors.Close$] from Actor[akka://reactivemongo/user/$b#-1700211063] to Actor[akka://reactivemongo/user/$a#-1418324178] was not delivered. [2] dead letters encountered. This logging can be turned off or adjusted with configuration settings 'akka.log-dead-letters' and 'akka.log-dead-letters-during-shutdown'. 

      

        
        
        
      

    

And the app doesn't exit either

So what am I doing wrong? I cannot find the answer ...

And it seems to me that the official docs don't explain if I should care about graceful completion at all.

I don't have much experience with console applications, I use the play framework in my projects, but I want to create a sub-project that works with mongodb

I see a lot of templates (in the activator) like: Play + Reactive Mongo, Play + Akka + Mongo, but there is no Scala + Reactive Mongo explaining how to work properly: /