Update 2021-10-31T14:19:00Z: We are done. Thank you for your patience and all your supportive tweets.

Update 2021-10-31T13:22:00Z: Today's work will be starting shortly. https://twitter.com/StackStatus/status/1454800691898339329 and https://stackstatus.net/post/666565626004979712/maintenance-beginning

Update 2021-10-30T17:07:00Z: The site is back. It took a lot longer than expected (our apologies) but we decided to take the safe/slow route rather than take some risks. Tomorrow's maintenance window is still required.

Update 2021-10-30T14:00:00Z: This will be starting soon. Once the website go into read-only mode it will last 1-2 hours. See https://twitter.com/StackStatus until we are back.

Due to ongoing planned network upgrades, all public Stack Exchange properties (stackoverflow.com, stackexchange.com, and so on) will be in read-only mode during two maintenance windows: Saturday, October 30 and Sunday, October 31, 2021.

While in read-only mode, the public Q&A network sites will be accessible, but no new content may be added or modified (questions, answers, comments, votes, etc.). Also, Teams will not be accessible as it requires authentication that is paused in read-only mode.

Once read-only mode starts, it is expected to last no more than 2 hours, though our goal is much shorter.

Before and after the window, updates will be added to this post. During the window, updates will be posted to https://twitter.com/StackStatus and https://stackstatus.net


What is happening?

This is the last of 4 major network hardware upgrades planned for 2021. While all of our network equipment is redundant and can usually be upgraded without downtime, there are a few rare procedures that are high risk or require us to switch to read-only mode to avoid actual downtime.

While these upgrades involve many days of actual work, we have minimized the user-visible interruption and isolated it outside of peak usage times.

Expect a blog post with the exciting details after we've had time to recover. This has been quite exhausting.

  • 15
    Will consecutive visit days be recorded during maintenance? (if not, I'll lose my 202 day streak) Oct 25, 2021 at 22:26
  • 17
    @Someone_who_likes_SE The site's only going to be down for two hours - I could understand your question if it were 8 or 12 or more but two hours out of a 24 hour window seems like a tiny one to be concerned about.
    – Catija
    Oct 25, 2021 at 23:01
  • 41
    I fully expect a Halloween-themed maintenance page.
    – OrangeDog
    Oct 26, 2021 at 10:54
  • 16
    SE being down is spooky enough @OrangeDog :D Oct 27, 2021 at 6:14
  • 5
    @OrangeDog LOL.
    – Tom Limoncelli StaffMod
    Oct 27, 2021 at 18:07
  • 2
    I saw a maintainance screen today for a few seconds, is that related?
    – dan1st
    Oct 29, 2021 at 13:29
  • 1
    @dan1st Not related. Must have been a fluke. The yellow banner that says we're in read-only mode is automatically generated and sometimes gets fooled.
    – Tom Limoncelli StaffMod
    Oct 29, 2021 at 18:26
  • 3
    @dan1st maybe it was just to spook you... for Halloween :P Oct 30, 2021 at 10:55
  • 3
    Completely unsurprisingly but quite annoyingly, the advice to check the StackStatus account on Twitter was useless because it had again not published any information about this "planned" outage (though apparently it was updated a while after the site was set to read-only). Do you really need your users to advise you on the usefulness of starting a practice to write down a list of things which you botched several times in the recent past?
    – tripleee
    Oct 30, 2021 at 17:26
  • 1
    I checked repeatedly during I think the first 15 minutes of the outage; nothing.
    – tripleee
    Oct 30, 2021 at 17:30
  • 1
    @tripleee Updates were delayed, but they were posted. Perhaps you would like to rephrase your comment a bit.
    – user707129
    Oct 30, 2021 at 17:34
  • 1
    Re v8: is it the forty-fifth day of October already?
    – rob
    Oct 30, 2021 at 18:40
  • 1
    "While all of our network equipment is redundant" doesn't sound too good (redundant: not or no longer needed or useful). How about "While all of our network equipment has resilience"? Oct 30, 2021 at 19:12
  • 9
    @AndrewMorton - "Redundant" is fairly commonly used to mean "duplicate components for reasons of fault-tollerance". It was the nearly-universal term before "resilience" became popular. See, for example: en.wikipedia.org/wiki/Redundancy_(engineering)
    – Ben Scott
    Oct 30, 2021 at 19:21
  • 2
    @BenScott I should have suggested "has redundancy." In the context of upgrading, "redundant" can easily be read to mean that the equipment is out-of-date. Not all SE sites are related to computer technology. Oct 30, 2021 at 20:12

1 Answer 1


Stack Overflow search was broken for the duration of the outage, returning a 500 internal server error. Is this a ? All other network sites' search pages were fine.

Screenshot of web browser displaying Stack Overflow Search page: "Oops! Something Bad Happened!"

  • I noticed this as well.
    – user1091571
    Oct 31, 2021 at 14:36
  • Friend of mine SMS'd this on, he used the latest Chrome. Nov 2, 2021 at 3:23

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