diagram.dot

digraph G {
  node [shape="box"]
  db [shape="cylinder" label="Database"]
  youtube_dl [label="YoutubeDL"]
  ui [label="UI"]
  sessions_pool [label="Sessions Pool"]
  youtube [label="Youtube.com"]
  fetcher [label="Fetcher"]



  subgraph cluster_0 {
		label = "Worker";

    fetcher -> youtube_dl
    youtube_dl -> sessions_pool
  }

  ui -> db
  fetcher -> db
  sessions_pool -> db
  youtube_dl -> youtube

  scheduler -> fetcher
}