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From "Philip O'Toole" <phi...@loggly.com>
Subject Re: Guaranteeing globally unique TimeUUID's in a high throughput distributed system
Date Sat, 16 Mar 2013 21:49:38 GMT
On Sat, Mar 16, 2013 at 2:40 PM, Philip O'Toole <philip@loggly.com> wrote:

> It is a mistake, IMHO, to use the timestamp contained within the event
> to generate the time-based UUID. While it will work, it suffers from
> exactly the problem you describe. Instead, use the clock of the host
> system to generate the timestamp. In otherwords, the event timestamp
> may be different from the timestamp in the UUID. In fact, it *will* be
> different, if the rate gets fast enough (since the 100ns period clock
> used to generate time-based UUIDs may not be fine-grained enough, and
> the UUID timestamp will increase as explained by RFC4122).

It is important that your systems run NTP, so time doesn't go
backwards. You could end up re-using IDs.

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