Thanks for the KIP, Patrick!
I agree with John that your KIP is well motivated.
I have just one minor feedback. Could you add store.range(null, null) to
the example snippets with the comment that this is equivalent to all()
(it is equivalent, right?)? This question about equivalence between
range(null, null) and all() came up in my mind when I read the KIP and I
think I am not the only one.
Regarding expanding the KIP to SessionStore and WindowStore, I think you
should not expand scope of the KIP. We can do the changes to the
SessionStore and WindowStore in a separate KIP. But it is your call!
Best,
Bruno
On 21.07.21 00:18, John Roesler wrote:
Thanks for the KIP, Patrick!
I think your KIP is well motivated. It's definitely a bummer
to have to iterate over the full store as a workaround for
open-ended ranges.
I agree with your pragmatic approach here. We have recently
had a couple of other contributions to the store APIs
(prefix and reverseRange), and the complexity of adding
those new methods far exceeded what anyone expected. I'd be
in favor of being conservative with new store APIs until we
are able to reign in that complexity somehow. Since your
proposed semantics seem reasonable, I'm in favor.
While reviewing your KIP, it struck me that we have several
range-like APIs on:
* SessionStore
(https://github.com/apache/kafka/blob/trunk/streams/src/main/java/org/apache/kafka/streams/state/ReadOnlySessionStore.java)
* WindowStore
(https://github.com/apache/kafka/blob/trunk/streams/src/main/java/org/apache/kafka/streams/state/ReadOnlyWindowStore.java)
as well.
Do you think it would be a good idea to also propose a
similar change on those APIs? It might be nice (for exactly
the same reasons you documented), but it also increases the
scope of your work. There is one extra wrinkle I can see:
SessionStore has versions of the range methods that take a
`long` instead of an `Instant`, so `null` wouldn't work for
them.
If you prefer to keep your KIP narrow in scope to just the
KeyValueStore, I'd also support you. In that case, it might
be a good idea to simply mention in the "Rejected
Alternatives" that you decided not to address those other
store APIs at this time. That way, people later on won't
have to wonder why those other methods didn't get updated.
Other than that, I have no concerns!
Thank you,
John
On Mon, 2021-07-19 at 13:22 +0200, Patrick Stuedi wrote:
Hi everyone,
I would like to start the discussion for KIP-763: Range queries with open
endpoints.
The KIP can be found here:
https://cwiki.apache.org/confluence/display/KAFKA/KIP-763%3A+Range+queries+with+open+endpoints
Any feedback will be highly appreciated.
Many thanks,
Patrick
