Compile warnings have been fixed.

src/main/scala/Main.scala

@@ -1,6 +1,5 @@
 import akka.actor.ActorSystem
 import akka.event.{LogSource, Logging, LoggingAdapter}
-import akka.stream.ActorMaterializer
 import analyzer.{Analyzer, Endpoint, HistoryWriter, Trainer}
 import com.datastax.oss.driver.api.core.CqlSession
 import com.typesafe.config.ConfigFactory
@@ -88,7 +87,6 @@ object Main extends App {
       }
 
       implicit val system: ActorSystem = ActorSystem("cluster", akkaConfig)
-      implicit val materializer: ActorMaterializer = ActorMaterializer()
       implicit val executionContext: ExecutionContext = system.dispatcher
 
       // Setup logging

src/main/scala/analyzer/Analyzer.scala

@@ -5,7 +5,6 @@ import akka.cluster.{Cluster, Member, MemberStatus}
 import akka.cluster.ClusterEvent.{CurrentClusterState, MemberUp}
 import akka.event.LoggingAdapter
 import akka.pattern.pipe
-import akka.stream.ActorMaterializer
 import akka.util.Timeout
 import lib.{BinarySerializer, CassandraClient, Config, Entry}
 import redis.RedisClient
@@ -31,9 +30,8 @@ final case class SensorMeta(
 final case class AllMeta(entries: List[SensorMeta])
 
 object Analyzer {
-  def props(cassandraClient: CassandraClient, redisClient: RedisClient)
-           (implicit materializer: ActorMaterializer) =
-    Props(classOf[Analyzer], cassandraClient, redisClient, materializer)
+  def props(cassandraClient: CassandraClient, redisClient: RedisClient) =
+    Props(classOf[Analyzer], cassandraClient, redisClient)
 
   // ANCHOR: withHeuristic begin
 
@@ -49,7 +47,7 @@ object Analyzer {
     val avg = history.sum / size
 
     def sqrDiff(x: Double) = (x - avg) * (x - avg)
-    val stdDev = math.sqrt((0.0 /: history)(_ + sqrDiff(_)) / size)
+    val stdDev = math.sqrt(history.foldLeft(0.0)(_ + sqrDiff(_)) / size)
 
     val valueDev = math.abs(value - avg)
     val anomaly = (valueDev - stdDev) / (2 * stdDev)
@@ -86,7 +84,6 @@ object Analyzer {
 }
 
 class Analyzer(cassandraClient: CassandraClient, redisClient: RedisClient)
-              (implicit materializer: ActorMaterializer)
   extends Actor with ActorLogging {
 
   private[this] val akkaCluster = Cluster(context.system)

src/main/scala/analyzer/Endpoint.scala

@@ -5,7 +5,6 @@ import akka.http.scaladsl.Http.ServerBinding
 import akka.http.scaladsl.model.{ContentTypes, HttpEntity, StatusCodes}
 import akka.http.scaladsl.server.Directives._
 import akka.pattern.ask
-import akka.stream.ActorMaterializer
 import akka.util.Timeout
 import lib._
 
@@ -14,15 +13,13 @@ import scala.concurrent.duration._
 import scala.concurrent.ExecutionContext
 
 object Endpoint {
-  def props(analyzerOpt: Option[ActorRef])
-           (implicit materializer: ActorMaterializer) =
-    Props(classOf[Endpoint], analyzerOpt, materializer)
+  def props(analyzerOpt: Option[ActorRef]) =
+    Props(classOf[Endpoint], analyzerOpt)
 
   final case object Stats
 }
 
 class Endpoint(analyzerOpt: Option[ActorRef])
-              (implicit materializer: ActorMaterializer)
   extends Actor with ActorLogging {
   import Endpoint._
 

src/main/scala/analyzer/HistoryWriter.scala

@@ -3,7 +3,6 @@ package analyzer
 import akka.actor._
 import akka.pattern.ask
 import akka.event.LoggingAdapter
-import akka.stream.ActorMaterializer
 import akka.util.Timeout
 import com.datastax.oss.driver.api.core.CqlSession
 import com.datastax.oss.driver.api.querybuilder.QueryBuilder._
@@ -18,15 +17,13 @@ import scala.concurrent.duration._
 import scala.util.{Failure, Success}
 
 object HistoryWriter {
-  def props(session: CqlSession, redisClient: RedisClient, analyzerOpt: Option[ActorRef])
-           (implicit materializer: ActorMaterializer) =
-    Props(classOf[HistoryWriter], session, redisClient, analyzerOpt, materializer)
+  def props(session: CqlSession, redisClient: RedisClient, analyzerOpt: Option[ActorRef]) =
+    Props(classOf[HistoryWriter], session, redisClient, analyzerOpt)
 
   private final case object Tick
 }
 
 class HistoryWriter(session: CqlSession, redisClient: RedisClient, analyzerOpt: Option[ActorRef])
-                   (implicit materializer: ActorMaterializer)
   extends Actor with ActorLogging {
   import HistoryWriter._
 
@@ -107,7 +104,9 @@ class HistoryWriter(session: CqlSession, redisClient: RedisClient, analyzerOpt:
     }
   }
 
-  system.scheduler.schedule(0.millis, conf.historyWriter.period.millis) {
-    self ! Tick
-  }
+  system.scheduler.scheduleWithFixedDelay(
+    Duration.Zero,
+    conf.historyWriter.period.millis,
+    self,
+    Tick)
 }

src/main/scala/analyzer/Trainer.scala

@@ -2,7 +2,6 @@ package analyzer
 
 import akka.actor._
 import akka.event.LoggingAdapter
-import akka.stream.ActorMaterializer
 import akka.util.Timeout
 import lib._
 import redis.RedisClient
@@ -13,18 +12,16 @@ import smile.data.formula._
 import scala.concurrent.duration._
 import scala.concurrent.ExecutionContext
 import scala.util.{Failure, Success, Try}
-import collection.JavaConverters._
+import scala.jdk.CollectionConverters._
 
 object Trainer {
-  def props(cassandraClient: CassandraClient, redisClient: RedisClient)
-           (implicit materializer: ActorMaterializer) =
-    Props(classOf[Trainer], cassandraClient, redisClient, materializer)
+  def props(cassandraClient: CassandraClient, redisClient: RedisClient) =
+    Props(classOf[Trainer], cassandraClient, redisClient)
 
   private final case object Tick
 }
 
 class Trainer(cassandraClient: CassandraClient, redisClient: RedisClient)
-             (implicit materializer: ActorMaterializer)
   extends Actor with ActorLogging {
   import Trainer._
 

src/main/scala/dashboard/Dashboard.scala

@@ -5,7 +5,6 @@ import akka.http.scaladsl.Http.ServerBinding
 import akka.http.scaladsl.model.{ContentTypes, HttpEntity}
 import akka.http.scaladsl.server.Directives._
 import akka.pattern.ask
-import akka.stream.ActorMaterializer
 import akka.util.Timeout
 import analyzer.Endpoint.Stats
 import lib._
@@ -15,15 +14,13 @@ import scala.concurrent.{ExecutionContext, Future}
 import scala.sys.process._
 
 object Dashboard {
-  def props(cassandraClient: CassandraClient, endpoint: ActorRef)
-           (implicit materializer: ActorMaterializer) =
-    Props(classOf[Dashboard], cassandraClient, endpoint, materializer)
+  def props(cassandraClient: CassandraClient, endpoint: ActorRef) =
+    Props(classOf[Dashboard], cassandraClient, endpoint)
 
   final case class Perf(timings: List[Double], actorStats: Map[String, Double])
 }
 
 class Dashboard(cassandraClient: CassandraClient, endpoint: ActorRef)
-               (implicit materializer: ActorMaterializer)
   extends Actor with ActorLogging {
   import Dashboard._
 
@@ -96,7 +93,7 @@ class Dashboard(cassandraClient: CassandraClient, endpoint: ActorRef)
     log.info(s"Querying $url")
     Process(runCmd).!
     // Second run, for stats
-    val stream = csvCmd lineStream_! ProcessLogger(_ => ())
+    val stream = csvCmd lazyLines_! ProcessLogger(_ => ())
     val values = stream.flatMap { (line) => line match {
       case CsvPattern(responseTime, dnsLookup, dns, requestWrite, responseDelay, responseRead) =>
         Some(responseTime.toDouble * 1000)

src/main/scala/lib/CassandraClient.scala

@@ -6,7 +6,7 @@ import com.datastax.oss.driver.api.core.cql.ResultSet
 import com.datastax.oss.driver.api.querybuilder.QueryBuilder._
 import com.datastax.oss.driver.api.querybuilder.relation._
 
-import scala.collection.JavaConverters._
+import scala.jdk.CollectionConverters._
 
 final case class Entry(sensor: String, ts: java.time.Instant, value: Double, anomaly: Int)
 

src/main/scala/lib/Config.scala

@@ -3,7 +3,7 @@ package lib
 import com.typesafe.config.{ConfigBeanFactory, ConfigFactory}
 
 import scala.beans.BeanProperty
-import scala.collection.JavaConverters._
+import scala.jdk.CollectionConverters._
 
 class MqttConfig {
   @BeanProperty var broker = ""

src/main/scala/lib/HttpClient.scala

@@ -7,7 +7,6 @@ import akka.http.scaladsl.Http.ServerBinding
 import akka.http.scaladsl.server._
 import akka.http.scaladsl.server.directives._
 import akka.http.scaladsl.server.Directives.{path, _}
-import akka.stream.ActorMaterializer
 
 import scala.concurrent.ExecutionContext
 import scala.concurrent.duration._
@@ -29,7 +28,6 @@ class HttpClient(
   supervisor: ActorRef
 )(implicit
   system: ActorSystem,
-  materializer: ActorMaterializer,
   executionContext: ExecutionContext
 ) {
   implicit val timeout: Timeout = Timeout(1.seconds)
@@ -50,7 +48,7 @@ class HttpClient(
       }
     }
 
-    Http().bindAndHandle(cdnExtended, address, port).onComplete {
+    Http().newServerAt(address, port).bind(cdnExtended).onComplete {
       case Success(binding) => supervisor ! HttpConnected(binding)
       case Failure(ex) => supervisor ! HttpConnectionFailure(ex)
     }

src/main/scala/mqtt/Consumer.scala

@@ -2,7 +2,6 @@ package mqtt
 
 import akka.actor._
 import akka.event.LoggingAdapter
-import akka.stream.ActorMaterializer
 import org.eclipse.paho.client.mqttv3._
 import com.datastax.oss.driver.api.core.CqlSession
 import com.datastax.oss.driver.api.querybuilder.QueryBuilder._
@@ -14,15 +13,13 @@ import mqtt.Producer.MqttEntry
 import scala.concurrent.ExecutionContext
 
 object Consumer {
-  def props(mqttClient: MqttClient, session: CqlSession)
-           (implicit materializer: ActorMaterializer) =
-    Props(classOf[Consumer], mqttClient, session, materializer)
+  def props(mqttClient: MqttClient, session: CqlSession) =
+    Props(classOf[Consumer], mqttClient, session)
 
   final case class Arrived(message: MqttMessage)
 }
 
 class Consumer(mqttClient: MqttClient, session: CqlSession)
-              (implicit materializer: ActorMaterializer)
   extends Actor with ActorLogging {
   import Consumer._
 

src/main/scala/mqtt/Producer.scala

@@ -5,7 +5,6 @@ import akka.event.LoggingAdapter
 import akka.http.scaladsl.Http.ServerBinding
 import akka.http.scaladsl.model.{ContentTypes, HttpEntity, StatusCodes}
 import akka.http.scaladsl.server.Directives._
-import akka.stream.ActorMaterializer
 import org.stringtemplate.v4._
 import org.eclipse.paho.client.mqttv3._
 import lib._
@@ -16,9 +15,8 @@ import scala.io.Source
 import scala.util.{Failure, Success}
 
 object Producer {
-  def props(mqttClient: MqttClient)
-           (implicit materializer: ActorMaterializer) =
-    Props(classOf[Producer], mqttClient, materializer)
+  def props(mqttClient: MqttClient) =
+    Props(classOf[Producer], mqttClient)
 
   final case class MqttEntry(sensor: String, value: Double, anomaly: Int)
   final case class SensorModel(name: String, isNormal: Boolean)
@@ -27,7 +25,6 @@ object Producer {
 }
 
 class Producer(mqttClient: MqttClient)
-              (implicit materializer: ActorMaterializer)
   extends Actor with ActorLogging {
   import Producer._
 
@@ -106,7 +103,9 @@ class Producer(mqttClient: MqttClient)
       log.error(s"Failed to establish HTTP connection $ex")
   }
 
-  system.scheduler.schedule(0.millis, conf.mqtt.timeout.millis) {
-    self ! Tick
-  }
+  system.scheduler.scheduleWithFixedDelay(
+    Duration.Zero,
+    conf.mqtt.timeout.millis,
+    self,
+    Tick)
 }

start.sc

@@ -9,7 +9,7 @@ val EnvDir = "target/env"
 def isCassandraRunning: Boolean = {
   val lsofPattern = raw"""p(\d+)""".r
   val lsof = Seq("lsof", "-Fp", "-i", ":9042")
-  lsof.lineStream_!.map {
+  lsof.lazyLines_!.map {
     case lsofPattern(_) => true
     case _ => false
   }.exists(x => x)