com.crobox.clickhouse.balancing.ClusterAwareHostBalancer.scala Maven / Gradle / Ivy

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package com.crobox.clickhouse.balancing

import akka.actor.{ActorRef, ActorSystem}
import akka.http.scaladsl.model.Uri
import akka.pattern.ask
import akka.util.Timeout
import com.crobox.clickhouse.balancing.discovery.ConnectionManagerActor.GetConnection
import com.crobox.clickhouse.balancing.discovery.cluster.ClusterConnectionProviderActor.ScanHosts
import com.crobox.clickhouse.discovery.ConnectionConfig

import scala.concurrent.Future
import scala.concurrent.duration._

/**
 * Host balancer that does a round robin on all the entries found in the `system.clusters` table.
 * It assumes that the service itself can access directly the clickhouse nodes and that the default port `8123` is used
 * for every node.
  **/
case class ClusterAwareHostBalancer(host: Uri,
                                    cluster: String = "cluster",
                                    manager: ActorRef,
                                    provider: ActorRef,
                                    scanningInterval: FiniteDuration)(
    implicit val system: ActorSystem,
    implicit val connectionRetrievalTimeout: Timeout
) extends HostBalancer {

  import system.dispatcher

  system.scheduler.schedule(Duration.Zero, scanningInterval, provider, ScanHosts(ConnectionConfig(host, cluster)))

  override def nextHost: Future[Uri] =
    (manager ? GetConnection()).mapTo[Uri]
}