Hi,
Thanks for the response.

Regarding

sm01 - I would prefer not a add group coordinator dependency on share
coordinator. Thats why we created coordinator-common.

Could we instead create a helper interface in share-coordinator to access
the relevant configs and pass the impl from BrokerServer (which has access
to relevant group config managers) to the share coordinator service?

sm04 - yes, lets add that one.

Rest of the answers are good.

Regards,
Sushant Mahajan

On Fri, 10 Jul 2026, 22:55 Muralidhar Basani via dev, <[email protected]>
wrote:

> Thanks again Sushant for the nice review.
>
> sm01
>
> True. share-coordinator has no compile dependency on group-coordinator. The
> KIP adds implementation project(':group-coordinator') to the
> share-coordinator build. There is no cyclic dep.
>
> ShareGroupConfigProvider gets a new accessor
> snapshotUpdateBytesPerSnapshotOrDefault(groupId, brokerDefault)
> ShareCoordinatorShard.Builder gets a new setter
> withShareGroupConfigProvider(.....) and ShareCoordinatorService.Builder
> gets the same setter.
> With these, BrokerServer can now construct the provider and pass it in. The
> shard can then communicate with the provider on both the write path
> (generateShareStateRecord) and the replay path (handleShareSnapshot),
> falling back to the broker-level default (when the group has no override).
>
> sm02
>
> Good point. A default value is not distinguishable from an explicit value
> via getLong() alone.
>
> I have updated KIP Public interfaces -> deprecated config section.
> 1. If share.coordinator.snapshot.update.bytes.per.snapshot is in
> originals() -> bytes mode.
> 2. Else if share.coordinator.snapshot.update.records.per.snapshot is in
> originals() -> records mode (deprecated path).
> 3. Else (neither explicitly set) -> bytes mode at the 20 mb default.
> 4. If both are in originals() -> bytes mode wins and a warn is logged.
>
> This resolution happens once at startup in ShareCoordinatorConfig, not
> per-record.
>
> sm03
>
> Cluster-roll backward compatibility
>
> During a rolling upgrade, yes brokers run mixed versions. Each broker's
> shard independently decides snapshot cadence, from its own local config. A
> newer broker replaying records written by an older broker (or other way
> around) interprets them identically. So cadence may differ in the mid-roll,
> but there is no on-disk format change and no coordination required I see. A
> broker that hasn't yet had the new config set, will simply use the 20 MB
> default. I have updated Compatibility section in the kip.
>
> sm04
>
> Currently the records-based didn't have any. A new metric
> bytes-since-snapshot (per __share_group_state partition) could be useful.
> Let me know if this is good, or any other suggestion?
>
> sm05
>
> The threshold is measured on uncompressed serialized record bytes. There is
> a little note in the kip mentioning that "Compression is not accounted for;
> the threshold is on uncompressed record bytes."
> Actually share.coordinator.state.topic.compression.codec defaults to NONE.
> So by default on-disk bytes equal the measured bytes; So it will not affect
> the 20mb limit, in default deploymnt.
>
> Thanks,
> Murali
>
> On Thu, Jul 9, 2026 at 7:25 PM Sushant Mahajan <[email protected]>
> wrote:
>
> > Hi,
> > Went over the new byte based approach.
> >
> > Few questions:
> >
> > sm01 - currently share coord module does not depend on the group
> > coordinator. Could you detail out how the new group level config will be
> > injected in the share coordinator?
> >
> > sm02 - since we have default defined as 20MB, how to differentiate
> between
> > older update count set vs byte limit set? The kip mentions if set byte
> > level will be honored. How to determine set vs default?
> >
> > sm03 - could you drop a line about backward compatibility in case of
> > cluster roll?
> >
> > sm04 - should we also add any new metrics?
> >
> > sm05 - do measurements need to take compression into account? Does it
> > affect the 20 MB limit?
> >
> > Regards,
> > Sushant Mahajan
> >
> > On Sun, 14 Jun 2026, 18:50 Muralidhar Basani via dev, <
> > [email protected]>
> > wrote:
> >
> > > Hi,
> > > Apologies for the delayed reply.
> > >
> > > Sushant, thanks for the reply. Just to flag the KIP has switched to
> > > bytes-based control (pls see below), which supersedes most of the
> > > records-based tuning discussion.
> > >
> > > Chia, thank you for the suggestions. Both the points are now in the
> KIP:
> > > - chia_00: broker floor stays at 0 (no compatibility break)
> > > - chia_01: bytes-based control adopted, matching
> > > metadata.log.max.record.bytes.between.snapshots, default 20 MB.
> > >
> > > Records-based config will be marked as deprecated.
> > >
> > > Updated KIP:
> > >
> > >
> >
> https://cwiki.apache.org/confluence/display/KAFKA/KIP-1349%3A+Bytes-based+configurable+snapshot+frequency+for+share+groups
> > >
> > > Please take a look again.
> > >
> > > Thanks,
> > > Murali
> > >
> > > On Thu, Jun 11, 2026 at 5:20 AM Chia-Ping Tsai <[email protected]>
> > > wrote:
> > >
> > > > hi
> > > >
> > > > chia_00: Changing the lower bound of the existing config is a
> > > > compatibility issue. If we want to avoid heavy snapshots, we can set
> > the
> > > > lower bound of the new group-level configuration to 200 by default.
> > Also,
> > > > the broker-level constraint should be changed to 0-1000, which won’t
> > > bring
> > > > compatibility issues
> > > >
> > > > chia_01: Have you considered using bytes instead of records as the
> > > > controlled unit?
> > > >
> > > >
> > > > On 2026/05/22 19:30:38 Muralidhar Basani via dev wrote:
> > > > > Hi all,
> > > > >
> > > > > I would like to start a discussion on KIP-1349, which allows
> > > configurable
> > > > > snapshot frequency of share groups.
> > > > >
> > > > > KIP :
> > > > >
> > > >
> > >
> >
> https://cwiki.apache.org/confluence/display/KAFKA/KIP-1349%3A+Configurable+snapshot+frequency+for+share+groups
> > > > >
> > > > > Thanks,
> > > > > Murali
> > > > >
> > > >
> > >
> >
>

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