The published set changing

The wait, in plain words

Strings get retired and strings get added. Services of this shape generally publish more than one for reasons of load and resilience, and the composition of that set is a decision the operator revisits. When it changes, some strings keep working, some stop, and sometimes an unfamiliar one appears alongside them.

Nothing announces this to you. There is no notice and no reason for one, because the people making the change are not managing your copy of the list. You find out when something you saved stops answering, or when you happen to look at the published set again.

That gap is the whole subject of this card. While it is open, the list you hold is a claim about the past that you are using as a claim about the present, and every attempt you make with it looks, from your side, exactly like a market that has gone away.

Underneath, while nothing moves

An onion address is derived from a key the operator holds. Publishing another one is cheap and costs nobody anything. Retiring one is a decision rather than an event you can observe, and the two do not have to happen together, which is why a set can gain a string long before it loses one.

In practice this means a string that stops answering could have been retired, could be under pressure, or could be one hop away from a problem that has nothing to do with the market. From outside those are indistinguishable, and this site is in no position to distinguish them either. What you can do first is read the string you already have, carefully: see reading the address string again.

The risky window has a shape worth naming. It opens when the published set changes and closes when your copy catches up. While it is open you are exposed to two things: wasted attempts against a string that will never answer again, and, far worse, receptiveness to a replacement offered by a stranger at exactly the moment you want one. The second is the reason this card exists at all.

There is no deadline running underneath this particular wait, which makes it the odd one in the band. What runs instead is a slow decay. The older your copy, the more likely it describes a set that no longer exists, and nothing will tell you which day that became true.

Behaving, and not behaving

A change you absorb cleanly and a change that catches you feel identical while they are happening. They differ in where the next string came from.

The distinguishing question is provenance, not appearance. Any string can be typed out and any page can be copied. Where you got it is the only property that is hard to fake, and so the only one worth checking.

A string going quiet also has an ordinary explanation that has nothing to do with rotation, which is why an address coming back is a real pattern rather than wishful thinking. Absence is not retirement until it stays absent.

Safe to do meanwhile

Everything useful here is preparation, done before the moment you need it.

• Keep the whole set, not one favouriteHolding a single string means one rotation removes your only way in.
• Compare character by characterA near miss and a match look the same at a glance, which is the entire point of a near miss.
• Try the others before concluding anythingOne silent string is a weak signal. The whole set silent is a different situation.
• Know what the worse case looks likeSo you can tell a rotation apart from something with no ceiling on it.

What makes it longer

The gap between a change and your knowledge of it stretches for ordinary reasons.

• You saved one string a long time ago and have not looked at the published set since.
• The change was partial, so most things still work and nothing prompts you to check anything.
• You are testing from a network or a circuit having problems of its own, which reads exactly like a dead address.
• You go looking during the gap, which is the moment you are least equipped to judge what you find.

What this card is not. This card is not a notice that anything has changed, and this site is in no position to issue one.