為什麼我的 Go MongoDB 伺服器中出現「接受錯誤：接受 tcp [::]:80:accept4:開啟檔案太多」？

var session *mgo.Session

func init() {

    var err error

    if session, err = mgo.Dial("localhost"); err != nil {

        log.Fatal(err)

    }

}

func someHandler(w http.ResponseWriter, r *http.Request) {

    sess := session.Copy()

    defer sess.Close() // Must close!

    c := sess.DB("mapdb").C("tiles")

    // Do something with the collection, e.g.

    var tile bson.M

    if err := c.FindId("someTileID").One(&result); err != nil {

        // Tile does not exist, send back error, e.g.:

        log.Printf("Tile with ID not found: %v, err: %v", "someTileID", err)

        http.NotFound(w, r)

        return

    }

    // Do something with tile

}