genserver实现打开redis状态

Question

我想打开一个redis连接，并为系统内的持续连接编写了类似的代码。我正在这样做的方式正在调用使用redix客户端的handle_info函数。 I have defined the dependency for redix

def start_link(opts \\ [name: __MODULE__]) do
    GenServer.start_link(__MODULE__, nil, Keyword.merge(opts, name: __MODULE__))
  end

  @impl true
  def init(_) do
    send(self(), :connect)
    {:ok, nil}
  end

  @impl true
  def handle_info(:connect, _conn) do
    host = "redis://localhost:6379/3"

    case Redix.start_link(host) do
      {:ok, conn} ->
        IO.inspect(conn)
        Process.monitor(conn.pid)
        {:noreply, conn}

      {:error, _} ->
       
        Process.send_after(self(), :connect, @reconnect_interval)
        {:noreply, nil}
    end
  end

I call with redix client to the server with handle info.当我使用PID设置redis中的键 something like this

Redix.command!(conn, ["SET", "queue"])

I get this error

    [error] GenServer Zuppler.Utils.Redis.Connection terminating
** (RuntimeError) attempted to cast GenServer Zuppler.Utils.Redis.Connection but no handle_cast/2 clause was provided
    (zuppler_utils 0.1.12) lib/gen_server.ex:824: Zuppler.Utils.Redis.Connection.handle_cast/2
    (stdlib 3.17.1) gen_server.erl:695: :gen_server.try_dispatch/4
    (stdlib 3.17.1) gen_server.erl:771: :gen_server.handle_msg/6
    (stdlib 3.17.1) proc_lib.erl:226: :proc_lib.init_p_do_apply/3
Last message: {:"$gen_cast", {:pipeline, [["llen", "list_name"]], {#PID<0.694.0>, #Reference<0.884395455.1828454401.122583>}, 5000}}
State: #PID<0.801.0>
** (EXIT from #PID<0.694.0>) shell process exited with reason: an exception was raised:
    ** (RuntimeError) attempted to cast GenServer Zuppler.Utils.Redis.Connection but no handle_cast/2 clause was provided
        (zuppler_utils 0.1.12) lib/gen_server.ex:824: Zuppler.Utils.Redis.Connection.handle_cast/2
        (stdlib 3.17.1) gen_server.erl:695: :gen_server.try_dispatch/4
        (stdlib 3.17.1) gen_server.erl:771: :gen_server.handle_msg/6
        (stdlib 3.17.1) proc_lib.erl:226: :proc_lib.init_p_do_apply/3

Answer 1

您已经拥有 IO.inspect(conn)，它必须向您显示 conn 是一个 pid。在下一行中，您尝试调用 conn.pid ，它被视为函数调用，映射到 :erlang.apply(#PID<0.1075.0>, :pid, [ ]) 并且明显加注。以下最有可能做到这一点。

- Process.monitor(conn.pid)
+ Process.monitor(conn)

---

旁注：使用 GenServer.handle_continue/2 回调，而不是向 self 发送消息，而 self 正是为这种初始化而存在的。

此外，通常会在应用程序监督树中启动 Redix，如 文档。