I (and several other users at the same time) have been periodically experiencing extremely slow page loads (including, at times, pages erroring out after trying to load for a while).

It appears to affect all pages on all sites. Sometimes, pages will load quickly, while others take many seconds to load, if the requests succeed at all. Then it will work normally for a while, before happening again some number of hours later.

It's happened numerous times over the past week or so. I can't pinpoint exactly when it started.

Is this more DDoS attacks? Something else?

(there may well be better tags than just but the tag search doesn't seem to want to work very well right now because...well, see above)

  • 10
    I run an uptime checking page - mainly for some stuff some of my community rund for ourselves but it also watches SO, SU and a few other network resources. It seems to detect SO being down for short periods i.stack.imgur.com/kgZE7.jpg May 5, 2022 at 13:10

1 Answer 1


We identified and addressed the cause of an intermittent slowness issue. It was not a DDoS attack, but rather resource exhaustion resulting from a site experiment. We are conducting further testing to confirm that the problem is completely fixed.

It took some time to find and rectify this because the problem only occurs sporadically and tends to clear up very quickly, but once we located the cause we were able to conclude the testing and mitigate its impact on site resources.

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    Thanks for the thorough investigation and update! I'm glad this problem has been sorted out; it has been very irritating to us, especially as we've been trying to fight an ongoing spam wave. Does "we were able to conclude the testing" mean that the A/B test of the "Trending" sort feature is now over (i.e., deactivated on Stack Overflow)? May 6, 2022 at 4:11
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    @CodyGray Correct, we had enough data collected to end early
    – Kyle Pollard StaffMod
    May 6, 2022 at 17:29
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    @Kyle just curious - how'd it go?
    – user1136431
    May 7, 2022 at 2:14
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    @richardec Lots of data collected and I expect there will be a clear leader. I'll save that analysis for when our data analyst goes through it, though. We'll be sure to post a fun data post. :)
    – Kyle Pollard StaffMod
    May 7, 2022 at 17:43
  • Ah, okay. Great! Anticipating...
    – user1136431
    May 7, 2022 at 18:54

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