anchor.diff:  open Suave.Model.Binding
   open Suave.Http.ServerErrors
   open HttpFs.Client
  +
  +//very important
  +System.Net.ServicePointManager.DefaultConnectionLimit <- 10000
   
   //helpers
   let guid guid = System.Guid.Parse(guid)
  
positive.code:       let managers = (jobId, manager) :: managers
        manager, managers
  
  let newJobManager () : actor<JobManager> =
    actor.Start(fun inbox ->
      let rec loop (managers : (Guid * actor<Manager>) list) =
        async {
          let! msg = inbox.Receive ()
          let uri = "http://localhost:8083"
          match msg with
          | Send(jobId, _) ->
            let manager, managers = getManager managers jobId
            manager.Post(Do(Process uri))
            return! loop managers
          | Stop jobId ->
            let manager, managers = getManager managers jobId
  
negative.code:   let stopWatch = System.Diagnostics.Stopwatch.StartNew()
    let request = createRequest Get <| Uri(uri)
    use response = getResponse request |> Async.RunSynchronously
    let responseTime = stopWatch.Elapsed.TotalMilliseconds
    printfn "%A" responseTime
  
  let newWorker manager : actor<Worker> =
    actor.Start(fun self ->
      let rec loop manager =
        async {
          let! msg = self.Receive ()
          match msg with
          | Worker.Do command ->
            match command with
            | Process uri -> doit uri
            return! loop manager
        }
      loop manager
    )
  
  let newManager () : actor<Manager> =
    actor.Start(fun self ->
      let rec loop status =
        async {
          let! msg = self.Receive ()
          match msg with
          | Manager.Do (count, command) ->
            match status with
            | Stopped ->
              printfn "Can't do work when the job is stopped"
              return! loop status
            | Running ->
              let workers = [ 1 .. count ] |> List.map (fun _ -> newWorker self)
              workers |> List.iter (fun worker -> worker.Post(Worker.Do(command)))
              return! loop status
          | Manager.Stop ->
            return! loop Stopped
  