Grafana stuck on loading for a long time

Now I’m using grafana dashboard daily. The grafana seems lose response from time to time.
Most cases are when loading a dashboard, but sometimes when I save the dashboard / goto dashboards list page, it also happens. The duration can be as long as minutes.
Sometimes the browser(Chrome) shows
waiting for available sockets

So I guess it’s nothing to do with templates. Maybe it’s about too many simultaneous requests.
Anyone knows this issue and is there a solution?

Can be caused by slow time series queries that take up all your browser request threads

Thanks for response, do you have any suggestions to ease this? like larger refresh interval?

Not really, investigate how long your time series queries take and if there is anything you can do to speed them up