# Related questions on sidebar missing

I noticed yesterday in a couple of questions and today in this one that, at least on my screen, the related questions are missing.

Why is this? Why does it only happen sometimes? Can I do it in such way that I can see it every time?

• I suppose that the system didn't find anything related; or that the sidebar has taken a quick sidebar and it will be back in the next episode of "Quests for Glory", err, I mean "Math S-E". – Asaf Karagila Sep 5 '14 at 14:20
• Seeing that no Related sidebars were generated since my answer, I'm retagging as a bug. – user147263 Sep 5 '14 at 16:51
• ... and now the problem went away. Related sidebar is shown for all questions expect the very new ones (posted within a few minutes). – user147263 Sep 6 '14 at 2:43
• @Haney: How is this a non-repro? The answer below indicates that this is "automatically solved" for sufficiently old questions, so the linked question will have a "Related" sidebar. Instead take a look at the newest question posted at time of seeing this comment. I still see the problem occurring (and it's an annoying one, since the "Related" bar often includes a good source for duplicates). – Asaf Karagila Sep 11 '14 at 22:54
• @Haney As of now, none of the questions posted since September 7 have the Related sidebar. Specifically, this one and all posted since then. – user147263 Sep 11 '14 at 23:35
• I can confirm Friday's predecessor's observation. And I can't say that I've entered the question linked in his question before, so it's definitely not a caching issue in this aspect. – Asaf Karagila Sep 12 '14 at 0:20
• Taking a look now, this is not working as expected and I was mistaken. – Haney Sep 12 '14 at 13:34

Well this was fun; basically, our background processing for these... stopped background processing. It looks like it is related to some async changes that were introduced (and possibly the dreaded sync-context deadlock that people using .NET Tasks may be aware of). So; we have a bit of a backlog to churn through, and it is going to take some time to catch up and be as responsive as we would like. To help with this, I have changed this code to scale out over more of our background processing servers (when there wasn't a backlog, it was working fine on a "one server wins and does everything" basis; with a backlog, it needs more concurrency). I'll keep an eye on it - hopefully it will have caught up soon!

It appears that the Related sidebar is slow to be built at the moment. To verify:

3. Check that earlier questions, starting from about the middle of page 2, have Related sidebar. Specifically, Prove that $V$ is a complete space is the most recent question with the Related sidebar.