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by jconley 5370 days ago
"What does matter is that the timestamp is new and increasing every second."

Right. I'm just sayin' that you have to be careful when you move data with a caveat like that. Moving the shard keyspace (the 13 bits) to a new machine that started generating ID's even one second behind (the first 4 bytes) would be troublesome, no?
2 comments
mikeyk 5370 days ago
Yep--definitely something to watch out for. At worst, though, you'd have a duplicate key when trying to insert, and can re-try without the risk of having a duplicate ID floating around your system.
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andrewf 5369 days ago
The lower rotating 10 bits should give them a reasonable safety margin. If they're creating less than 128 entries in a particular shard per second (right now they're doing that across their entire datastore), their clocks would need to be out by 8 seconds to cause a problem.

They should definitely be monitoring their clocks though :)

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