Load test setup

BlazeServer.scala

import cats.effect._
import org.http4s.implicits._
import org.http4s.server.blaze.BlazeServerBuilder
import org.http4s.server.middleware.Logger
import scala.concurrent.ExecutionContext.global

object BlazeServer extends IOApp {

  def server: IO[Nothing] = {
    val app = Logger.httpApp(true, true)(routes.orNotFound)

    BlazeServerBuilder[IO](global)
      .bindHttp(9000, "0.0.0.0")
      .withHttpApp(app)
      .resource
      .use(_ => IO.never)
  }

  override def run(args: List[String]): IO[ExitCode] =
    server.as(ExitCode.Success)
    
}

EmberServer.scala

import cats.effect._
import org.http4s.implicits._
import org.http4s.ember.server.EmberServerBuilder
import org.http4s.server.middleware.Logger

object EmberServer extends IOApp {

  def server: IO[Nothing] = {
    val app = Logger.httpApp(true, true)(routes.orNotFound)

    EmberServerBuilder.default[IO]
      .withHttpApp(app)
      .withHost("0.0.0.0")
      .withPort(9000)
      .build
      .use(_ => IO.never)
  }

  override def run(args: List[String]): IO[ExitCode] =
    server.as(ExitCode.Success)
    
}

package.scala

import cats.effect.IO
import org.http4s.HttpRoutes
import org.http4s.dsl.Http4sDsl

package object http4sloadtests {
  
  def routes: HttpRoutes[IO] = {
    val dsl = new Http4sDsl[IO]{}
    import dsl._
    HttpRoutes.of {
      case GET -> Root =>
        Ok("OK")
      case GET -> Root / "health" =>
        Ok("OK")
    }
  }
}