XSETID

Introduction and Use Case(s)

XSETID is a Redis command used to change the ID of an existing stream. This can be useful in scenarios where you need to reset the ID sequence for a stream, often for replication or data recovery purposes.

Syntax

  1. XSETID <stream> <new_id>

Parameter Explanations

  • <stream>: The name of the stream whose ID you want to set.
  • <new_id>: The new ID to set for the stream. This should be in the format milliseconds-sequence.

Return Values

The command returns OK if the operation is successful.

Code Examples

  1. dragonfly> XADD mystream * name "Alice"
  2. "1657899999999-0"
  3. dragonfly> XADD mystream * name "Bob"
  4. "1657900000000-0"
  5. dragonfly> XLEN mystream
  6. (integer) 2
  7. dragonfly> XSETID mystream 1657900000000-1
  8. OK
  9. dragonfly> XLEN mystream
  10. (integer) 2
  11. dragonfly> XADD mystream * name "Charlie"
  12. "1657900000000-2"
  13. dragonfly> XRANGE mystream - +
  14. 1) 1) "1657899999999-0"
  15.    2) 1) "name"
  16.       2) "Alice"
  17. 2) 1) "1657900000000-0"
  18.    2) 1) "name"
  19.       2) "Bob"
  20. 3) 1) "1657900000000-2"
  21.    2) 1) "name"
  22.       2) "Charlie"

Best Practices

  • Ensure that the new ID is greater than the last ID in the stream to avoid conflicts.
  • Use XSETID judiciously as improper use might lead to data consistency issues, especially in replicated environments.

Common Mistakes

  • Setting <new_id> to an ID that is less than or equal to the current maximum ID in the stream. This will cause subsequent additions to the stream to fail with an error.

FAQs

Can I use XSETID to decrease the ID sequence?

No, the new ID must always be greater than the current maximum ID in the stream to maintain the order of entries.

What happens if I set an invalid ID format?

Redis will return an error indicating that the ID format is invalid. Ensure the ID follows the milliseconds-sequence format.