Hi, Jiunn-Yang, Thanks for the KIP.
I find auto.offset.reset.latest.max.age a bit weird. It only applies when auto.offset.reset is latest. However, it seems that the motivation equally applies when auto.offset.reset is set to other values like by_duration. The intention is that we want to have a separate way to control newly created partitions vs existing partitions when the group starts. Have we considered adding a new config like auto.offset.reset.new.partitions? If this new config is not set, the offset reset policy defaults to the policy used for existing partitions. The user could set it explicitly to customize the behavior for new partitions. Jun On Thu, May 7, 2026 at 5:07 AM 黃竣陽 <[email protected]> wrote: > Hi all, > > I’d like to manually bump this thread. > > Best Regards, > Jiunn-Yang > > > 黃竣陽 <[email protected]> 於 2026年5月1日 晚上10:37 寫道： > > > > Hello all, > > > > Thanks for the feedback. > > > > DJ01/DJ02: > > > > MetadataResponse bumps from v13 to v14. The PartitionMetadata struct > gains a new > > field PartitionAgeMs (int64, default -1), computed server-side by the > broker as > > broker_current_time - partition_creation_time. > > > > Also add the consumer heartbeat flow. when MembershipManager detects a > newly assigned > > partition, it explicitly invalidates the metadata for the affected topic > and forces a fresh MetadataRequest > > before making the offset reset decision, even if the topic ID is already > in the cache. > > > > MB0: > > > > The consumer learns the broker's maximum supported MetadataResponse > version via the > > ApiVersions negotiation at connection time. If the negotiated version is > unsupported, the consumer > > knows the broker does not support PartitionAgeMs at all and can throw an > UnsupportedVersionException > > immediately, rather than silently falling back to latest and risking > data loss without any operator-visible signal. > > > > MB1/MB2/MB3: > > > > I have addressed these changes in the KIP. > > > > Best Regards, > > Jiunn-Yang > > > >> Chia-Ping Tsai <[email protected]> 於 2026年4月29日 下午4:04 寫道： > >> > >> hi David > >> > >> I agree with the direction of moving the 'age' resolution from the > Heartbeat API to the Metadata API to keep the control plane clean. The main > trade-off, as we noted before, is introducing inter-broker clock skew. The > Group Coordinator approach provided a single source of truth for time. > >> > >> However, realistically, this time skew should be negligible. Given that > the max.age threshold will likely be configured in minutes or hours, a > typical NTP skew (in milliseconds) between brokers won't impact the > fallback decision. > >> > >> Best, > >> Chia-Ping > >> > >>> David Jacot via dev <[email protected]> 於 2026年4月29日 下午3:29 寫道： > >>> > >>> Hi all, > >>> > >>> Thanks for the KIP! > >>> > >>> Sorry, I haven't really followed the previous conversation but I took a > >>> quick look at this one. > >>> > >>> DJ01: I don't clearly understand the flow with the > ConsumerGroupHeartbeat > >>> API after reading the KIP. There is a new boolean; the KIP states that > >>> partition ages are returned only when this boolean is set. Implicitly, > this > >>> means that when the consumer receives a new partition, it will issue a > new > >>> HB request with the boolean set to receive the ages. Is my > understanding > >>> correct? We should perhaps clarify the flow and also explain how it > fits > >>> into the existing flow (e.g. list offsets, fetch offsets, etc.). > >>> DJ02: It my understanding is correct, I wonder if > >>> the ConsumerGroupHeartbeat API is the right place for this given that > a new > >>> round trip is done anyway. Alternatively, it could simply include the > >>> metadata. Generally, we should be rather cautious about not overloading > >>> the ConsumerGroupHeartbeat API with unrelated concepts. The API is a > >>> control plane API for assigning or revoking partitions. The fact that > we > >>> don't want to add it to the corresponding Streams API also suggests > >>> something is not quite right. What would we do if we want to support > >>> Streams in the future? > >>> > >>> Best, > >>> David > >>> > >>>> On Wed, Apr 29, 2026 at 12:28 AM Muralidhar Basani via dev < > >>>> [email protected]> wrote: > >>>> > >>>> Hi Jiunn, > >>>> > >>>> Thank you for this great kip. Good to know about the gap. > >>>> > >>>> mb-0 - why a new v2 version bump for RequestPartitionAges field. Can a > >>>> tagged field (for ex: on response, PartitionAges on TopicPartitions) > be > >>>> used here and avoid version bump? > >>>> > >>>> mb-1 - For the new config, is there a recommended value or a ConfigDef > >>>> validator? Probably it should based on the metadata.max.age.ms ? > Sizing > >>>> instructions can be part of javadocs I guess. > >>>> > >>>> mb-2 - (minor) As there are no changes to Kafka Streams, would it be > better > >>>> to add this new config auto.offset.reset.latest.max.age to the > >>>> StreamsConfig block list (NON_CONFIGURABLE_CONSUMER_DEFAULT_CONFIGS) > for a > >>>> clear warning, incase users configure it? This is the most familiar > >>>> consumer config and users might easily mistakenly configure it. Or > may be > >>>> it's not worth it to add. > >>>> > >>>> mb-3 - (minor) The phrasing "the consumer falls back to earliest" > reads as > >>>> if the config were being changed per-partition which isn't supported. > May > >>>> be rephrasing to something like "consumer resolves the initial > position to > >>>> start offset for that partition" as if earliest was applied to that > >>>> partition only and auto.offset.reset config is unchanged. > >>>> > >>>> Thanks, > >>>> Murali > >>>> > >>>>> On Tue, Apr 28, 2026 at 2:48 PM 黃竣陽 <[email protected]> wrote: > >>>>> > >>>>> Hi chia, > >>>>> > >>>>> I have updated the KIP to include this change. > >>>>> > >>>>> Best Regards, > >>>>> Jiunn-Yang > >>>>> > >>>>>> Chia-Ping Tsai <[email protected]> 於 2026年4月28日 晚上8:03 寫道： > >>>>>> > >>>>>> hi Jiunn-Yang > >>>>>> > >>>>>> chia_0: Should we expose the partition creation time via the Admin > API? > >>>>> I assume it would be valuable for users to diagnose and troubleshoot > the > >>>>> behavior of auto.offset.reset.latest.max.age > >>>>>> > >>>>>> Best, > >>>>>> Chia-Ping > >>>>>> > >>>>>> On 2026/04/28 10:47:58 黃竣陽 wrote: > >>>>>>> Hello everyone, > >>>>>>> > >>>>>>> I would like to start a discussion on KIP-1327 Prevent Hot Data > Loss > >>>> on > >>>>> Partition Expansion for Latest Policy > >>>>>>> < > >>>> > https://urldefense.com/v3/__https://cwiki.apache.org/confluence/x/KY4mGQ__;!!Ayb5sqE7!qF4q1QzF1RRgP61D7A2xuEai1ky7fepKDKFFvpNBuePikH-ULmT87TvuuZzy5kau5E4y5zMZAmfQQiwZomM$ > >>>>> > >>>>>>> > >>>>>>> This proposal aims to introduces auto.offset.reset.latest.max.age, > a > >>>>> consumer config that lets the > >>>>>>> latest reset policy distinguish newly expanded (hot) partitions > from > >>>>> long-existing (cold) ones. Partitions > >>>>>>> younger than the configured threshold automatically fall back to > >>>>> earliest, preventing silent data loss > >>>>>>> during topic expansion without forcing a full historical reprocess. > >>>>>>> > >>>>>>> Best regards, > >>>>>>> Jiunn-Yang > >>>>> > >>>>> > >>>> > > > >
