Comment by kibwen

While I agree with other commenters that a server should be able to gracefully handle the relatively small amount of traffic being generated here, I'm sympathetic to the notion that in this specific instance the problem is exacerbated by all the servers making their requests at almost exactly the same instant, i.e. the Thundering Herd Problem https://en.wikipedia.org/wiki/Thundering_herd_problem . If Mastodon wanted to address this, servers could add a small amount of random delay before fetching a link preview.