How long is a SQS MessageID globally unique?

Question

The [documentation](https://docs.aws.amazon.com/AWSSimpleQueueService/latest/APIReference/API_Message.html) for SQS Messages says this about MessageIDs:

```
[It is a] unique identifier for the message. A MessageId is considered unique across all AWS accounts for an extended period of time.
```

Is there a lower bound to the amount of time that constitutes "an extended period of time"?

Answer

The message ID is a UUID, and as such, it is considered unique, although theoretically, they can repeat.

From [Wikipidia](https://en.wikipedia.org/wiki/Universally_unique_identifier): 
*When generated according to the standard methods, UUIDs are, for practical purposes, unique. Their uniqueness does not depend on a central registration authority or coordination between the parties generating them, unlike most other numbering schemes. While the probability that a UUID will be duplicated is not zero, it is generally considered close enough to zero to be negligible.*

What do you need it for?

Answer

**From FAQ - How long can I keep my messages in Amazon SQS message queues?**

*Longer message retention provides greater flexibility to allow for longer intervals between message production and consumption. You can configure the Amazon SQS message retention period to a value from 1 minute to 14 days. The default is 4 days. Once the message retention quota is reached, your messages are automatically deleted.*

> So message would only be to be associated to a specific message ID for a maximum of 14 days.

How long is a SQS MessageID globally unique?

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