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by greatgib 44 days ago
Normally it should not have been, with cache and all, but that was the past...

Think about what would happen the day that letsencrypt is borken for whatever reason technical or like having a retarded US leader and being located in the wrong country. Taken into account the push of letsencrypt with major web browsers to restrict certificate validities for short periods like only a few days...
1 comments
muvlon 44 days ago
Let's Encrypt has to be down for days before people begin to feel the pain. DNS is very different, it breaks stuff immediately everywhere.
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tharkun__ 44 days ago
No it doesn't. DNS breaks as soon as TTLs run out. It's your choice to set them so low that stuff breaks immediately.
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__float 44 days ago
What do you recommend then? DNS doesn't usually change that often, but if you mess it up when it does, you're in for some pain if TTLs are high!
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htgb 44 days ago
Not the one you're replying to, but I'd keep TTL high normally and lower it one TTL ahead of a planned change.
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kenniskrag 43 days ago
I would define high as "double time needed to fix a dns issue" and account for weekends
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stouset 43 days ago
This is the way.
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account42 43 days ago
Unfortunately you can't set DNS TTL arbitrarily high (or low) without some resolvers ignoring your suggestion and using arbitrary values.
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Arnt 43 days ago
Most historical outages lasted minutes or hours. One arguably lasted much longer, when someone lost control of their servers due to civil war.

I haven't followed this closely, but have there been any... shall we say plain outages longer than six hours? That's not an outrageous TTL. Or a day.

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ale42 43 days ago
This assumes that the host name you want has been recently queried. If it's not cached, good luck...
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tharkun__ 43 days ago
TL;DR: If it's not cached, does it really matter if it's offline for some time?

Long version:

If you're so popular all around that you really really want a very very short TTL, people will query all the time from all the places that "count", won't they? So it's gonna be cached.

If you're not so popular or not all around, what does it matter even if you had a very very short TTL? You're not loosing much.

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