Hi folks,

Notes from today's metrics architecture sync are in the usual doc:
https://docs.google.com/document/d/100h7c4damrUzVuquYbBHM0EvA4LSWuW2IT2dN_7nYVA/edit?pli=1&tab=t.18iv1m7p6i6b

Highlights:

Module placement. core/ now holds the entity data model only. A new spi/
takes every other shared contract: feature SPIs, feature non-SPI contracts,
substrate SPIs, substrate non-SPI contracts, and contract-required types.
That settles the question PR #5204 reopened, by placing into a new SPI
module. Note that it changes slightly towards the referenced WIP RFC [1]
recommendations: what proposed to place in core/, now should go to spi/
except for the entity data model.

Metrics PRs. #5068 merged. #5204 needs reshaping onto the split. #4115 and
#4756 stay open with action on the author to follow up on review comments.

[1]
https://docs.google.com/document/d/1mj3vGpix9zTDTFFJKtWT5ZxI3PTGI1YNb5xFqyWrOkc/edit?tab=t.0

On Wed, Jul 15, 2026 at 11:01 AM Anand Kumar Sankaran via dev <
[email protected]> wrote:

> Thanks EJ.  My plan is to introduce PR0 in a new branch / PR and repurpose
> #4115 and #4756 for PR1 and PR2 to maintain all the valuable discussions
> that happened there.
>
> From: EJ Wang <[email protected]>
> Date: Wednesday, July 15, 2026 at 10:41 AM
> To: [email protected] <[email protected]>
> Subject: Re: Proposal for REST endpoints for table metrics and events
>
> Hi folks, Thanks again for the discussion today. I updated the sync doc
> with notes from today's metrics sync: https: //urldefense. com/v3/__https:
> //docs. google.
> com/document/d/100h7c4damrUzVuquYbBHM0EvA4LSWuW2IT2dN_7nYVA/edit?pli=1&tab=t.
> 2ahd7wze5f__;!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrXJwAz1g0$
>
>
> Hi folks,
>
> Thanks again for the discussion today. I updated the sync doc with notes
> from today's metrics sync:
>
> https://urldefense.com/v3/__https://docs.google.com/document/d/100h7c4damrUzVuquYbBHM0EvA4LSWuW2IT2dN_7nYVA/edit?pli=1&tab=t.2ahd7wze5f__;!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrXJwAz1g0$
>
> See highlights below:
>
> In previous meetings, EJ proposed a two prs framing to push forward the
> metrics query work in polaris. Dmitri pointed out a subtle point that pr2
> is currently also trying to do the persistence related code placement
> refactor. For the sake of straightforward review process, EJ, Dmitri and
> Anand (the author) agreed to separate the persistence refactoring into pr0,
> and reframing the pr scopes as follow:
>
>    1.
>
>    Pr0: refactor irc metrics spi
>    1.
>
>       SPI should stay in core/ with metric type enveloped
>       2.
>
>       default spi impl, no-op, in extensions/ - default selection at
>       runtime/
>       3.
>
>       move metrics persistence and correspondings to extensions/ as an
>       alternative SPI impl
>       2.
>
>    Pr1: rest api for query
>
> https://urldefense.com/v3/__https://github.com/apache/polaris/pull/4115/changes__;!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrXFCbEbRk$
>    1.
>
>       rest api spec in extensions/ as optional spec
>       2.
>
>       SPI in extensions/ as optional spec spi
>       3.
>
>       default spi impl in extensions/ no-op
>       4.
>
>       handler related in runtime/ - thin adaptor from http shape to spi
>       shape
>       3.
>
>    Pr2: jdbc impl for query
> https://urldefense.com/v3/__https://github.com/apache/polaris/pull/4756__;!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrXRVMBzqE$
>    1.
>
>       alternative spi impl in extensions/ -> query with jdbc
>
>
> Thanks,
> -ej
>
> On Wed, Jul 1, 2026 at 8:01 AM Alexandre Dutra <[email protected]> wrote:
>
> > Hi all,
> >
> > > While the current implementation stores metrics in the metastore, other
> > deployments
> > may choose a KV store, a dedicated metrics warehouse, or another backend
> > entirely. In those cases, exposing a Polaris REST API over a specific
> > schema feels like coupling the API to an implementation detail.
> >
> > I wouldn't say to an implementation detail, but rather to a particular
> > setup / configuration. I think that's fine. If you don't store
> > metrics, you don't read metrics. Similar situations will certainly
> > happen in the future, e.g. if we ever introduce an API to read events,
> > that would only work if events are being persisted in the first place.
> > Again I think that's a fair trade-off.
> >
> > Thanks,
> > Alex
> >
> > On Wed, Jul 1, 2026 at 7:23 AM Dmitri Bourlatchkov <[email protected]>
> > wrote:
> > >
> > > Hi Yufei,
> > >
> > > From my POV, it is fine for Polaris to have multiple REST API surfaces
> > with
> > > different features and different degrees of "readiness". Each API can
> > > evolve fairly independently. With proper modularization (which Anand
> > did),
> > > changes to the main Polaris code and these extra modules should
> normally
> > be
> > > non-intrusive to each other.
> > >
> > > I assume Anand is going to be the first user of this API. However, if
> we
> > do
> > > not merge it we'll never know whether other users are interested. I do
> > not
> > > think many end users read the dev ML, but they certainly read the docs,
> > > code and release notes.
> > >
> > > There is no risk for Polaris as a project in exposing this experimental
> > > API. If usage dwindles over time, we can remove it. If it gains a
> > > considerable user / contributor base, we will promote it to a
> > "first-class"
> > > (non-beta) API.
> > >
> > > Cheers,
> > > Dmitri.
> > >
> > > On Tue, Jun 30, 2026 at 7:53 PM Yufei Gu <[email protected]> wrote:
> > >
> > > > Hi all,
> > > >
> > > > Thanks for driving this work forward. Building this as a POC makes
> > perfect
> > > > sense if the goal is to validate the idea and gather feedback. Should
> > we
> > > > merge a POC into the main branch before agreeing on the overall
> > direction?
> > > > To me, that feels like a separate discussion from whether the
> > > > implementation itself looks reasonable.
> > > >
> > > > One concern that I don't think has been fully addressed is whether we
> > need
> > > > to expose metrics consumption through a Polaris REST endpoint at all.
> > > >
> > > > My concern is less about the API itself and more about the boundary
> > Polaris
> > > > should own. The proposed REST API is tied to a particular persistence
> > > > schema, but that schema is just one possible implementation. While
> the
> > > > current implementation stores metrics in the metastore, other
> > deployments
> > > > may choose a KV store, a dedicated metrics warehouse, or another
> > backend
> > > > entirely. In those cases, exposing a Polaris REST API over a specific
> > > > schema feels like coupling the API to an implementation detail.
> > > >
> > > > Polaris isn't intended to become a full metrics system. I'd expect it
> > to
> > > > focus on producing metrics and let deployments choose the most
> > appropriate
> > > > storage and consumption model for their environment.
> > > >
> > > > I'm not opposed to exploring this direction, but we should first
> align
> > on
> > > > whether exposing a REST API through Polaris is the right long term
> > approach
> > > > before merging it into the main branch.
> > > >
> > > > Thanks,
> > > > Yufei
> > > >
> > > > Yufei
> > > >
> > > >
> > > > On Mon, Jun 29, 2026 at 9:27 AM Dmitri Bourlatchkov <
> [email protected]>
> > > > wrote:
> > > >
> > > > > Hi All,
> > > > >
> > > > > It looks like Anand addressed all action items in [4115].
> > > > >
> > > > > Please review the latest state of the code. The PR LGTM and I
> > approved in
> > > > > GH from my side.
> > > > >
> > > > > [4115]
> https://urldefense.com/v3/__https://github.com/apache/polaris/pull/4115__;!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrXtFRscKs$
> > > > >
> > > > > Thanks,
> > > > > Dmitri.
> > > > >
> > > > > On Thu, Jun 25, 2026 at 1:56 PM Dmitri Bourlatchkov <
> > [email protected]>
> > > > > wrote:
> > > > >
> > > > > > Hi All,
> > > > > >
> > > > > > Recap of the discussion in today's Community Sync:
> > > > > >
> > > > > > * The modular approach for Metrics SPI(s) and implementation
> seems
> > to
> > > > > have
> > > > > > community consensus (please comment if you still have concerns)
> > > > > >
> > > > > > * What modules / feature flags are enabled in Apache Polaris
> > images by
> > > > > > default will be discussed later (when the feature is close to
> > > > > completion).
> > > > > >
> > > > > > In any case, users will be able to turn the full feature on/off
> at
> > > > their
> > > > > > discretion, regardless of the default flag values.
> > > > > >
> > > > > > * It is generally preferable to have smaller PRs and introduce
> new
> > > > > > features gradually to simplify reviews.
> > > > > >
> > > > > > What this means for the Metrics API, IMHO is:
> > > > > >
> > > > > > a) The scope of PR 4115 is probably ok as it stands right now. If
> > > > someone
> > > > > > wants to propose splitting it further, please comment.
> > > > > >
> > > > > > b) After 4115 is merged, Metrics Persistence PRs will follow,
> with
> > > > > smaller
> > > > > > scope per PR as appropriate for the nature of the code changes.
> > > > > >
> > > > > > * The major concern was about exposing the new Metrics REST API
> to
> > end
> > > > > > users. The nature of this concern was about avoiding the (false)
> > > > > impression
> > > > > > that the new API is a firm and adopted Polaris specification.
> > > > > >
> > > > > > I think this concern is reasonable.
> > > > > >
> > > > > > I propose that Anand update the documentation sections of PR 4115
> > to
> > > > > > emphasise that the API is currently an experimental / POC API at
> > this
> > > > > time
> > > > > > and is subject to change (including breaking changes). I believe
> it
> > > > > already
> > > > > > has the "beta" label. So this request is mostly for doc changes
> to
> > > > > clarify
> > > > > > user expectations, since the "beta" label alone may not be
> > interpreted
> > > > > the
> > > > > > same way by all users.
> > > > > >
> > > > > > I hope this update will resolve all remaining concerns with 4115
> > and
> > > > > allow
> > > > > > for it to be merged so that the community will be able to proceed
> > to
> > > > > > follow-up PRs (as noted above).
> > > > > >
> > > > > > Please add/correct me if I missed anything relevant.
> > > > > >
> > > > > > Thanks,
> > > > > > Dmitri.
> > > > > >
> > > > > > On Wed, Jun 24, 2026 at 8:11 PM Yufei Gu <[email protected]>
> > wrote:
> > > > > >
> > > > > >> I do not think we have agreement on the query REST APIs yet.
> > > > > >>
> > > > > >> In particular, the current query API shape seems highly coupled
> > to the
> > > > > >> *example[1]* metrics in the Iceberg REST spec. I do not think
> > that is
> > > > a
> > > > > >> good way to design a REST API contract. For example, fields like
> > > > > >> resultDataFiles, resultDeleteFiles, totalFileSizeBytes,
> > > > > >> totalDataManifests,
> > > > > >> totalDeleteManifests, and scannedDataManifests are very specific
> > to
> > > > one
> > > > > >> style of scan metric. That makes the API look more like a direct
> > > > > >> projection
> > > > > >> of the current example payload than a general query model.
> > > > > >>
> > > > > >> My preference is that Polaris should not define or strongly
> opine
> > on
> > > > the
> > > > > >> Iceberg scan or commit metrics query REST API at this point.
> > Polaris
> > > > can
> > > > > >> resolve and authorize the table, accept the metrics report, and
> > > > delegate
> > > > > >> it
> > > > > >> to the configured reporting path. Durable storage, filtering,
> > > > > dashboards,
> > > > > >> and query APIs should remain downstream impl. choices unless and
> > until
> > > > > the
> > > > > >> Iceberg community standardizes a query contract, which I doubt
> > will
> > > > > >> happen.
> > > > > >>
> > > > > >> So I do not think the intake path has to be blocked, but I would
> > > > prefer
> > > > > >> not
> > > > > >> to merge a Polaris specific query API that may be hard to evolve
> > > > later.
> > > > > >>
> > > > > >> 1.
> > > > > >>
> > > > > >>
> > > > >
> > > >
> >
> https://urldefense.com/v3/__https://github.com/apache/iceberg/blob/2a6c556c0c883c04c6d3fbd68e6aeda36b91e0aa/open-api/rest-catalog-open-api.yaml*L4152__;Iw!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrXCDsqYGo$
> > > > > >>
> > > > > >> Yufei
> > > > > >>
> > > > > >>
> > > > > >> On Tue, Jun 23, 2026 at 9:30 AM Dmitri Bourlatchkov <
> > [email protected]
> > > > >
> > > > > >> wrote:
> > > > > >>
> > > > > >> > Hi All,
> > > > > >> >
> > > > > >> > So, what are the blockers for merging [4115], if any?
> > > > > >> >
> > > > > >> > [4115]
> https://urldefense.com/v3/__https://github.com/apache/polaris/pull/4115__;!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrXtFRscKs$
> > > > > >> >
> > > > > >> > Thanks,
> > > > > >> > Dmitri.
> > > > > >> >
> > > > > >> > On Wed, Jun 17, 2026 at 5:28 PM EJ Wang <
> > > > > [email protected]
> > > > > >> >
> > > > > >> > wrote:
> > > > > >> >
> > > > > >> > > Hi folks,
> > > > > >> > >
> > > > > >> > > Thanks again for the discussion today. I updated the sync
> doc
> > with
> > > > > >> notes
> > > > > >> > > from today's metrics sync:
> > > > > >> > >
> > > > > >> > >
> > > > > >> > >
> > > > > >> >
> > > > > >>
> > > > >
> > > >
> >
> https://urldefense.com/v3/__https://docs.google.com/document/d/100h7c4damrUzVuquYbBHM0EvA4LSWuW2IT2dN_7nYVA/edit?tab=t.ezk0rgdx0c6m__;!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrX83IZkm0$
> > > > > >> > >
> > > > > >> > > A few highlights:
> > > > > >> > >
> > > > > >> > >    - No objection to keeping the default metrics behavior
> > small:
> > > > > >> > >    no-op/log-only is enough as the built-in default.
> > > > > >> > >    - Durable storage, event forwarding, external queues,
> > > > dashboards,
> > > > > >> and
> > > > > >> > >    custom filtering should be implementation choices behind
> > the
> > > > > >> metrics
> > > > > >> > >    reporting path.
> > > > > >> > >    - For PR #4115, the REST layer should
> resolve/authz/accept
> > the
> > > > > >> report,
> > > > > >> > >    then delegate to the selected metrics implementation. It
> > should
> > > > > not
> > > > > >> > own
> > > > > >> > >    durable storage semantics.
> > > > > >> > >    - The rough boundary we discussed is: spec owns the wire
> > > > > contract,
> > > > > >> > >    runtime owns framework wiring, API/contract modules own
> > > > > >> > provider-facing
> > > > > >> > >    contracts, and extensions own replaceable
> implementations.
> > > > > >> > >    - OpenLineage has a similar path-naming question. We
> should
> > > > avoid
> > > > > >> > >    occupying a generic lineage path too early if we want
> room
> > for
> > > > > >> other
> > > > > >> > >    lineage systems later.
> > > > > >> > >
> > > > > >> > > I believe the boundary rules previewed in sync meeting are
> > useful
> > > > > for
> > > > > >> > > reviewing PR #4115, but it is not
> > > > > >> > > a final module-layout proposal.
> > > > > >> > >
> > > > > >> > > For metrics specifically, I think the target remains:
> > > > > >> > >    runtime
> > > > > >> > >      -> metrics reporting/emitting contract
> > > > > >> > >      -> default implementation
> > > > > >> > >           -> lower implementation details, if needed
> > > > > >> > >
> > > > > >> > > That keeps the default simple, while allowing durable JDBC,
> > > > > >> event-backed,
> > > > > >> > > or external-queue implementations to be added separately.
> > > > > >> > >
> > > > > >> > > We also touched on the split between Iceberg metrics
> emitting
> > and
> > > > > >> > > Polaris-owned metrics querying. The querying side can keep
> > > > evolving,
> > > > > >> > > especially for dashboard or generic-table use cases, but I
> do
> > not
> > > > > >> think
> > > > > >> > > that needs to block the intake path in this PR.
> > > > > >> > >
> > > > > >> > > Thanks,
> > > > > >> > > -ej
> > > > > >> > >
> > > > > >> > > On Tue, Jun 16, 2026 at 2:17 PM Yufei Gu <
> > [email protected]>
> > > > > >> wrote:
> > > > > >> > >
> > > > > >> > > > Thanks for chiming in, EJ. Agreed that the default battery
> > > > should
> > > > > >> stay
> > > > > >> > > > small. I'm leaning toward not including metrics
> persistence
> > in
> > > > the
> > > > > >> > > default
> > > > > >> > > > battery.
> > > > > >> > > >
> > > > > >> > > > Yufei
> > > > > >> > > >
> > > > > >> > > >
> > > > > >> > > > On Thu, Jun 11, 2026 at 8:30 PM EJ Wang <
> > > > > >> > [email protected]>
> > > > > >> > > > wrote:
> > > > > >> > > >
> > > > > >> > > > > Hi Yufei,
> > > > > >> > > > >
> > > > > >> > > > > Thanks for connecting this back to the REST endpoint
> > > > proposal. I
> > > > > >> > > replied
> > > > > >> > > > > with the fuller version on the event-forwarding thread,
> > but
> > > > > >> wanted to
> > > > > >> > > add
> > > > > >> > > > > the shorter version here too.
> > > > > >> > > > >
> > > > > >> > > > > I agree that metrics reporting/emitting is the right
> > > > conceptual
> > > > > >> > > boundary,
> > > > > >> > > > > and I also think the event/listener path is a good
> > > > > implementation
> > > > > >> > > > direction
> > > > > >> > > > > to explore. The distinction I want to keep clear is
> > default
> > > > > >> battery
> > > > > >> > vs
> > > > > >> > > > > extension implementation.
> > > > > >> > > > >
> > > > > >> > > > > For the REST/API side, I would keep the semantics
> narrow:
> > > > > Polaris
> > > > > >> > > > resolves
> > > > > >> > > > > and authorizes the table, accepts the Iceberg
> scan/commit
> > > > > metrics
> > > > > >> > > report
> > > > > >> > > > > into the configured reporting/emitting path, and returns
> > 204.
> > > > > That
> > > > > >> > 204
> > > > > >> > > > > should mean Polaris accepted the report into the
> ingestion
> > > > path;
> > > > > >> it
> > > > > >> > > > should
> > > > > >> > > > > not imply durable storage.
> > > > > >> > > > >
> > > > > >> > > > > Durable storage, event forwarding, external telemetry
> > routing,
> > > > > >> > > filtering,
> > > > > >> > > > > and retention should sit behind that reporting/emitting
> > > > boundary
> > > > > >> as
> > > > > >> > > > > implementation-layer behavior. A durable JDBC path can
> be
> > one
> > > > > >> named
> > > > > >> > > > > extension implementation. An event/listener forwarding
> > path
> > > > can
> > > > > be
> > > > > >> > > > another
> > > > > >> > > > > named extension implementation.
> > > > > >> > > > >
> > > > > >> > > > > So I am +1 on the event-forwarding idea as a non-default
> > > > > extension
> > > > > >> > > > > implementation. I just would not make it the default
> > battery
> > > > or
> > > > > >> the
> > > > > >> > > core
> > > > > >> > > > > API shape. The default battery can stay small and safe,
> > while
> > > > > >> > > deployments
> > > > > >> > > > > that need forwarding, dashboards, or durable storage can
> > opt
> > > > > into
> > > > > >> the
> > > > > >> > > > > implementation that matches their operational model.
> > > > > >> > > > >
> > > > > >> > > > > Thanks,
> > > > > >> > > > > -ej
> > > > > >> > > > >
> > > > > >> > > > > On Wed, Jun 10, 2026 at 11:43 AM Yufei Gu <
> > > > [email protected]
> > > > > >
> > > > > >> > > wrote:
> > > > > >> > > > >
> > > > > >> > > > > > Thanks EJ. I agree that the reporting/emitting
> boundary
> > > > feels
> > > > > >> like
> > > > > >> > > the
> > > > > >> > > > > > right SPI boundary, but I wonder if we can simplify
> this
> > > > even
> > > > > >> > > further.
> > > > > >> > > > > >
> > > > > >> > > > > > Iceberg scan and commit metrics look very similar to
> > events
> > > > to
> > > > > >> me.
> > > > > >> > > They
> > > > > >> > > > > are
> > > > > >> > > > > > append only, asynchronously consumed, often forwarded
> to
> > > > > >> external
> > > > > >> > > > > systems,
> > > > > >> > > > > > and have similar retention and cleanup requirements.
> > More
> > > > > >> details
> > > > > >> > can
> > > > > >> > > > be
> > > > > >> > > > > > found in this thread [1]. In that case, Polaris may
> only
> > > > need
> > > > > to
> > > > > >> > > accept
> > > > > >> > > > > the
> > > > > >> > > > > > report and emit an event through the existing event
> > > > framework.
> > > > > >> > > > Filtering,
> > > > > >> > > > > > async delivery, custom sinks, and retention mechanisms
> > could
> > > > > >> then
> > > > > >> > be
> > > > > >> > > > > shared
> > > > > >> > > > > > instead of introducing a separate metrics specific
> > extension
> > > > > >> layer
> > > > > >> > > and
> > > > > >> > > > > SPI.
> > > > > >> > > > > >
> > > > > >> > > > > > The main requirement I still see is querying metrics
> > through
> > > > > >> > Polaris.
> > > > > >> > > > If
> > > > > >> > > > > we
> > > > > >> > > > > > want that battery included experience, we could work
> on
> > a
> > > > > >> > persistence
> > > > > >> > > > > > listener implementation that selectively saves metrics
> > and
> > > > > >> expose
> > > > > >> > it
> > > > > >> > > > via
> > > > > >> > > > > > the IRC event endpoint which seems pretty close in
> > Iceberg
> > > > > >> > > > > > community. Another option I like more is to allow
> users
> > to
> > > > > >> develop
> > > > > >> > > > their
> > > > > >> > > > > > own listener, so they can persist scan/commit metrics
> > to any
> > > > > >> > systems
> > > > > >> > > > they
> > > > > >> > > > > > prefer. In general, that feels like an implementation
> > choice
> > > > > on
> > > > > >> top
> > > > > >> > > of
> > > > > >> > > > > the
> > > > > >> > > > > > event framework rather than something that needs to
> > shape
> > > > the
> > > > > >> core
> > > > > >> > > > > > architecture.
> > > > > >> > > > > >
> > > > > >> > > > > > 1.
> > > > > >> >
> >
> https://urldefense.com/v3/__https://lists.apache.org/thread/x9j8nscvy8hq61tyn01mj8yp6n9of0kp__;!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrXGcGDgks$
> > > > > >> > > > > >
> > > > > >> > > > > > Thanks,
> > > > > >> > > > > > Yufei
> > > > > >> > > > > >
> > > > > >> > > > > >
> > > > > >> > > > > > On Thu, Jun 4, 2026 at 5:14 PM EJ Wang <
> > > > > >> > > [email protected]
> > > > > >> > > > >
> > > > > >> > > > > > wrote:
> > > > > >> > > > > >
> > > > > >> > > > > > > Good point. I agree the existing
> > PolarisMetricsReporter is
> > > > > >> > already
> > > > > >> > > > very
> > > > > >> > > > > > > close to the right conceptual boundary. I am not
> > > > proposing a
> > > > > >> > second
> > > > > >> > > > > > > parallel reporter concept. The distinction I am
> > trying to
> > > > > >> make is
> > > > > >> > > > > > narrower:
> > > > > >> > > > > > >
> > > > > >> > > > > > > Current state:
> > > > > >> > > > > > >
> > > > > >> > > > > > >    - PolarisMetricsReporter is the existing metrics
> > > > > reporting
> > > > > >> > hook.
> > > > > >> > > > > > >    - But it currently lives under runtime/service.
> > > > > >> > > > > > >    - Its contract is documented around Quarkus/CDI
> > > > discovery
> > > > > >> and
> > > > > >> > > > > > > @Identifier
> > > > > >> > > > > > >    selection.
> > > > > >> > > > > > >    - The default implementation is log-only.
> > > > > >> > > > > > >    - The durable implementation writes through
> > > > > >> > > PolarisMetricsManager
> > > > > >> > > > > and
> > > > > >> > > > > > >    MetricsPersistence.
> > > > > >> > > > > > >    - MetricsPersistence is currently inherited by
> > > > > >> > BasePersistence.
> > > > > >> > > > > > >
> > > > > >> > > > > > > My proposal:
> > > > > >> > > > > > >
> > > > > >> > > > > > >    - Keep the reporting/emitting boundary as the
> SPI.
> > > > > >> > > > > > >    - Revise that contract in a framework-agnostic
> > optional
> > > > > >> > Iceberg
> > > > > >> > > > > > *metrics
> > > > > >> > > > > > >    extension API layer*.
> > > > > >> > > > > > >    - Keep runtime/service responsible for REST
> > ingestion,
> > > > > >> > > table/authz
> > > > > >> > > > > > >    validation, and runtime wiring.
> > > > > >> > > > > > >    - Keep the battery implementation log-only in the
> > > > metrics
> > > > > >> > > > extension
> > > > > >> > > > > > API
> > > > > >> > > > > > >    layer, *not under runtime/service*.
> > > > > >> > > > > > >    - Treat durable JDBC metrics as one
> implementation
> > of
> > > > the
> > > > > >> > > > reporting
> > > > > >> > > > > > SPI.
> > > > > >> > > > > > >    - Decompose the MetricsPersistence and
> > BasePersistence
> > > > > >> > coupling
> > > > > >> > > as
> > > > > >> > > > > > >    durable implementation detail.
> > > > > >> > > > > > >
> > > > > >> > > > > > > So the difference is not “new reporter concept vs
> old
> > > > > reporter
> > > > > >> > > > > concept.”
> > > > > >> > > > > > > but:
> > > > > >> > > > > > >
> > > > > >> > > > > > >
> > > > > >> > > > > > >    - PolarisMetricsReporter today = runtime/service
> > > > > CDI-shaped
> > > > > >> > > hook.
> > > > > >> > > > > > >    - Target reporting SPI = same conceptual
> boundary,
> > but
> > > > > >> placed
> > > > > >> > in
> > > > > >> > > > the
> > > > > >> > > > > > >    right extension API layer and kept
> > framework-agnostic.
> > > > > >> > > > > > >
> > > > > >> > > > > > > For the current metrics PR, I think the minimal
> > > > > architectural
> > > > > >> > > cleanup
> > > > > >> > > > > > > before merge is to *put the reporting SPI contract
> > and the
> > > > > >> > battery
> > > > > >> > > > > > default
> > > > > >> > > > > > > in the right place*. The durable JDBC
> implementation,
> > > > > >> > event-backed
> > > > > >> > > > > async
> > > > > >> > > > > > > implementation, external queue support, and deeper
> > > > > persistence
> > > > > >> > > > cleanup
> > > > > >> > > > > > can
> > > > > >> > > > > > > continue as follow-ups, as long as we do not lock
> the
> > SPI
> > > > > >> > boundary
> > > > > >> > > to
> > > > > >> > > > > > > BasePersistence or to runtime/service wiring.
> > > > > >> > > > > > >
> > > > > >> > > > > > > -ej
> > > > > >> > > > > > >
> > > > > >> > > > > > > On Wed, Jun 3, 2026 at 3:00 PM Dmitri Bourlatchkov <
> > > > > >> > > [email protected]
> > > > > >> > > > >
> > > > > >> > > > > > > wrote:
> > > > > >> > > > > > >
> > > > > >> > > > > > > > Hi EJ,
> > > > > >> > > > > > > >
> > > > > >> > > > > > > > Thanks for the recap / summary!
> > > > > >> > > > > > > >
> > > > > >> > > > > > > > > Do folks agree that the stable SPI boundary
> > should be
> > > > > >> > > > > > > > metrics reporting/emitting, not metrics
> persistence?
> > > > > >> > > > > > > >
> > > > > >> > > > > > > > SGTM.
> > > > > >> > > > > > > >
> > > > > >> > > > > > > > > Does an optional Iceberg metrics extension API
> > layer
> > > > > sound
> > > > > >> > like
> > > > > >> > > > the
> > > > > >> > > > > > > right
> > > > > >> > > > > > > > home for this SPI?
> > > > > >> > > > > > > >
> > > > > >> > > > > > > > How is that different from current
> > > > PolarisMetricsReporter?
> > > > > >> > > > > > > >
> > > > > >> > > > > > > > > Should the current durable metrics work be
> > reframed
> > > > as a
> > > > > >> > > durable
> > > > > >> > > > > > > > JDBC reference implementation of that SPI?
> > > > > >> > > > > > > >
> > > > > >> > > > > > > > SGTM.
> > > > > >> > > > > > > >
> > > > > >> > > > > > > > > What is the smallest PR sequence to get there
> > without
> > > > > >> > blocking
> > > > > >> > > > > > > > the current metrics work unnecessarily?
> > > > > >> > > > > > > >
> > > > > >> > > > > > > > Let's get
> >
> https://urldefense.com/v3/__https://github.com/apache/polaris/pull/4397__;!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrXuu5jefU$
> > > > > >> merged
> > > > > >> > > > first.
> > > > > >> > > > > > > >
> > > > > >> > > > > > > > Then, I'd propose isolating the Metrics schema
> from
> > the
> > > > > >> > MetaStore
> > > > > >> > > > > > schema.
> > > > > >> > > > > > > > This will probably have some ripple effect into
> the
> > > > > >> bootstrap
> > > > > >> > > > > > workflows,
> > > > > >> > > > > > > so
> > > > > >> > > > > > > > it's not a trivial change.
> > > > > >> > > > > > > >
> > > > > >> > > > > > > > Then, let's reassess.
> > > > > >> > > > > > > >
> > > > > >> > > > > > > > Cheers,
> > > > > >> > > > > > > > Dmitri.
> > > > > >> > > > > > > >
> > > > > >> > > > > > > > On Wed, Jun 3, 2026 at 5:40 PM EJ Wang <
> > > > > >> > > > > [email protected]
> > > > > >> > > > > > >
> > > > > >> > > > > > > > wrote:
> > > > > >> > > > > > > >
> > > > > >> > > > > > > > > Hi folks,
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > > Thanks again for the discussion today. I updated
> > the
> > > > > sync
> > > > > >> doc
> > > > > >> > > > with
> > > > > >> > > > > > > notes
> > > > > >> > > > > > > > > from the third metrics architecture sync:
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > >
> > > > > >> > > > > > >
> > > > > >> > > > > >
> > > > > >> > > > >
> > > > > >> > > >
> > > > > >> > >
> > > > > >> >
> > > > > >>
> > > > >
> > > >
> >
> https://urldefense.com/v3/__https://docs.google.com/document/d/100h7c4damrUzVuquYbBHM0EvA4LSWuW2IT2dN_7nYVA/edit?tab=t.k96s2xyqr5u1__;!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrXrqCL-QE$
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > > A few highlights from today’s discussion:
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >    - We clarified that Iceberg metrics reporting
> > can
> > > > be
> > > > > >> > > > interpreted
> > > > > >> > > > > > > > either
> > > > > >> > > > > > > > >    as sync or async handling from Polaris’s
> > > > perspective,
> > > > > >> so
> > > > > >> > > > Polaris
> > > > > >> > > > > > > > should
> > > > > >> > > > > > > > >    stay flexible as a platform instead of baking
> > one
> > > > > >> handling
> > > > > >> > > > model
> > > > > >> > > > > > > into
> > > > > >> > > > > > > > > the
> > > > > >> > > > > > > > >    REST API behavior.
> > > > > >> > > > > > > > >    - We aligned that the built-in (battery)
> > behavior
> > > > for
> > > > > >> > > metrics
> > > > > >> > > > > > > emitting
> > > > > >> > > > > > > > >    can stay simple: no-op/log-only is enough as
> > the
> > > > > >> default.
> > > > > >> > > > > > > > >    - Durable metrics persistence should be
> > treated as
> > > > an
> > > > > >> > > > > > implementation
> > > > > >> > > > > > > > of
> > > > > >> > > > > > > > >    the metrics reporting path, not as the core
> SPI
> > > > > >> boundary.
> > > > > >> > > > > > > > >    - The existing durable metrics work can be
> > reviewed
> > > > > as
> > > > > >> a
> > > > > >> > > > > reference
> > > > > >> > > > > > > > >    implementation of the reporting SPI, with
> > > > > >> > > persistence-related
> > > > > >> > > > > > logic
> > > > > >> > > > > > > > kept
> > > > > >> > > > > > > > >    self-contained under a metrics durable
> > > > implementation
> > > > > >> > module
> > > > > >> > > > > > rather
> > > > > >> > > > > > > > than
> > > > > >> > > > > > > > >    scattered through core entity persistence.
> > > > > >> > > > > > > > >    - Dashboard/insights remains a real use case,
> > but
> > > > we
> > > > > >> > agreed
> > > > > >> > > to
> > > > > >> > > > > > keep
> > > > > >> > > > > > > it
> > > > > >> > > > > > > > >    separate from the core metrics intake
> > discussion
> > > > for
> > > > > >> now.
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > > I also did a quick source check after the
> meeting
> > to
> > > > > make
> > > > > >> > sure
> > > > > >> > > we
> > > > > >> > > > > are
> > > > > >> > > > > > > > > describing the current state accurately.
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > > Current state:
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >    - Polaris already has a metrics reporting
> hook:
> > > > > >> > > > > > > > PolarisMetricsReporter.
> > > > > >> > > > > > > > >    - The default implementation is
> > > > > DefaultMetricsReporter,
> > > > > >> > > > selected
> > > > > >> > > > > > by
> > > > > >> > > > > > > > >
> > polaris.iceberg-metrics.reporting.type=default. It
> > > > is
> > > > > >> > > > log-only,
> > > > > >> > > > > > > > >    effectively quiet unless metrics logging is
> > > > enabled.
> > > > > >> > > > > > > > >    - There is also a PersistingMetricsReporter,
> > > > selected
> > > > > >> by
> > > > > >> > > > > > > > >
> > polaris.iceberg-metrics.reporting.type=persisting,
> > > > > >> which
> > > > > >> > > > > converts
> > > > > >> > > > > > > > >    Iceberg scan/commit reports into Polaris
> > metrics
> > > > > >> records
> > > > > >> > and
> > > > > >> > > > > > writes
> > > > > >> > > > > > > > > through
> > > > > >> > > > > > > > >    PolarisMetricsManager -> MetricsPersistence.
> > > > > >> > > > > > > > >    - MetricsPersistence currently exists in the
> > > > > >> persistence
> > > > > >> > > layer
> > > > > >> > > > > and
> > > > > >> > > > > > > is
> > > > > >> > > > > > > > >    inherited by BasePersistence.
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > > My read from the discussion is that the target
> > > > boundary
> > > > > >> > should
> > > > > >> > > > not
> > > > > >> > > > > be
> > > > > >> > > > > > > > > MetricsPersistence as inherited by
> > BasePersistence.
> > > > That
> > > > > >> path
> > > > > >> > > > > should
> > > > > >> > > > > > be
> > > > > >> > > > > > > > > decomposed as durable implementation detail
> (taken
> > > > care
> > > > > >> of by
> > > > > >> > > > > > > > >
> https://urldefense.com/v3/__https://github.com/apache/polaris/pull/4397__;!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrXuu5jefU$).
> The
> > > > > stable
> > > > > >> > > > extension
> > > > > >> > > > > > > point
> > > > > >> > > > > > > > > should instead be the metrics reporting/emitting
> > > > > boundary.
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > > Concretely, I think the next proposal should be
> > shaped
> > > > > >> like
> > > > > >> > > this:
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >    1.
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >    Define the proper metrics reporting SPI at an
> > > > > optional
> > > > > >> > > Iceberg
> > > > > >> > > > > > > metrics
> > > > > >> > > > > > > > >    extension API layer.
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >    Example direction:
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >    public interface IcebergMetricsReporter {
> > > > > >> > > > > > > > >      void
> reportMetric(IcebergMetricsReportContext
> > > > > >> context,
> > > > > >> > > > > > > > > MetricsReport report);
> > > > > >> > > > > > > > >    }
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >    The context would carry the small
> > Polaris-resolved
> > > > > >> > envelope:
> > > > > >> > > > > > > > >    catalog/table identity, report type, received
> > > > > >> timestamp,
> > > > > >> > and
> > > > > >> > > > > > > > > request/trace
> > > > > >> > > > > > > > >    context if available. The raw Iceberg
> > MetricsReport
> > > > > >> > remains
> > > > > >> > > > the
> > > > > >> > > > > > > > payload.
> > > > > >> > > > > > > > >    2.
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >    Keep runtime/service as the REST ingestion
> and
> > > > wiring
> > > > > >> > layer.
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >    The REST handler still resolves the table and
> > > > > performs
> > > > > >> > authz
> > > > > >> > > > > > before
> > > > > >> > > > > > > > >    accepting the report. After that, it calls
> the
> > > > > selected
> > > > > >> > > > > reporting
> > > > > >> > > > > > > > >    implementation.
> > > > > >> > > > > > > > >    3.
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >    Keep the battery default no-op/log-only.
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >    This preserves an out-of-box safe default and
> > > > avoids
> > > > > >> > > > requiring a
> > > > > >> > > > > > > > durable
> > > > > >> > > > > > > > >    metrics store for every Polaris deployment.
> > > > > >> > > > > > > > >    4.
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >    Move durable JDBC metrics into a
> self-contained
> > > > > >> > > implementation
> > > > > >> > > > > of
> > > > > >> > > > > > > the
> > > > > >> > > > > > > > >    reporting SPI.
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >    That implementation can own its schema,
> > bootstrap,
> > > > > >> > > retention,
> > > > > >> > > > > and
> > > > > >> > > > > > > read
> > > > > >> > > > > > > > >    API support. It should not define the core
> > > > reporting
> > > > > >> SPI
> > > > > >> > > > > boundary,
> > > > > >> > > > > > > and
> > > > > >> > > > > > > > > it
> > > > > >> > > > > > > > >    should not require metrics persistence to
> > remain
> > > > > >> inherited
> > > > > >> > > > from
> > > > > >> > > > > > > > >    BasePersistence.
> > > > > >> > > > > > > > >    5.
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >    Treat async/event-backed handling as another
> > > > > >> > implementation
> > > > > >> > > of
> > > > > >> > > > > the
> > > > > >> > > > > > > > same
> > > > > >> > > > > > > > >    reporting SPI.
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >    For example, an event-backed reporter could
> > > > enqueue a
> > > > > >> > > metrics
> > > > > >> > > > > > event
> > > > > >> > > > > > > > and
> > > > > >> > > > > > > > >    let listeners handle durable storage or other
> > > > sinks.
> > > > > >> If we
> > > > > >> > > > later
> > > > > >> > > > > > > need
> > > > > >> > > > > > > > a
> > > > > >> > > > > > > > >    replaceable queue engine, that seems like a
> > shared
> > > > > >> > > > event/metrics
> > > > > >> > > > > > > > > substrate
> > > > > >> > > > > > > > >    topic rather than a metrics-only requirement.
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > > This framing lets us keep the REST metrics
> > endpoint
> > > > > >> simple,
> > > > > >> > > > > preserve
> > > > > >> > > > > > > the
> > > > > >> > > > > > > > > current default behavior, support durable
> metrics
> > > > users,
> > > > > >> and
> > > > > >> > > > still
> > > > > >> > > > > > > leave
> > > > > >> > > > > > > > > room for async/event-backed or
> > external-queue-based
> > > > > >> > > > > implementations.
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > > I think the main follow-up questions are:
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > >    - Do folks agree that the stable SPI boundary
> > > > should
> > > > > be
> > > > > >> > > > metrics
> > > > > >> > > > > > > > >    reporting/emitting, not metrics persistence?
> > > > > >> > > > > > > > >    - Does an optional Iceberg metrics extension
> > API
> > > > > layer
> > > > > >> > sound
> > > > > >> > > > > like
> > > > > >> > > > > > > the
> > > > > >> > > > > > > > >    right home for this SPI?
> > > > > >> > > > > > > > >    - Should the current durable metrics work be
> > > > reframed
> > > > > >> as a
> > > > > >> > > > > durable
> > > > > >> > > > > > > > JDBC
> > > > > >> > > > > > > > >    reference implementation of that SPI?
> > > > > >> > > > > > > > >    - What is the smallest PR sequence to get
> there
> > > > > without
> > > > > >> > > > blocking
> > > > > >> > > > > > the
> > > > > >> > > > > > > > >    current metrics work unnecessarily?
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > > Thanks,
> > > > > >> > > > > > > > > -ej
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > > On Fri, May 15, 2026 at 5:16 PM Dmitri
> > Bourlatchkov <
> > > > > >> > > > > > [email protected]>
> > > > > >> > > > > > > > > wrote:
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > > > Hi JB,
> > > > > >> > > > > > > > > >
> > > > > >> > > > > > > > > > Could you set up another meeting, please? Same
> > time
> > > > on
> > > > > >> > > > Wednesday
> > > > > >> > > > > as
> > > > > >> > > > > > > > last
> > > > > >> > > > > > > > > > time... I hope it works for everyone.
> > > > > >> > > > > > > > > >
> > > > > >> > > > > > > > > > Cheers,
> > > > > >> > > > > > > > > > Dmitri.
> > > > > >> > > > > > > > > >
> > > > > >> > > > > > > > > > On Fri, May 15, 2026 at 8:06 PM Yufei Gu <
> > > > > >> > > [email protected]
> > > > > >> > > > >
> > > > > >> > > > > > > wrote:
> > > > > >> > > > > > > > > >
> > > > > >> > > > > > > > > > > +1 on another sync call next week.
> > > > > >> > > > > > > > > > >
> > > > > >> > > > > > > > > > > Yufei
> > > > > >> > > > > > > > > > >
> > > > > >> > > > > > > > > > >
> > > > > >> > > > > > > > > > > On Fri, May 15, 2026 at 4:52 PM Dmitri
> > > > Bourlatchkov
> > > > > <
> > > > > >> > > > > > > > [email protected]>
> > > > > >> > > > > > > > > > > wrote:
> > > > > >> > > > > > > > > > >
> > > > > >> > > > > > > > > > > > Hi All,
> > > > > >> > > > > > > > > > > >
> > > > > >> > > > > > > > > > > > WDYT about another sync call next week?
> > > > > >> > > > > > > > > > > >
> > > > > >> > > > > > > > > > > > Thanks,
> > > > > >> > > > > > > > > > > > Dmitri.
> > > > > >> > > > > > > > > > > >
> > > > > >> > > > > > > > > > > > On Wed, May 6, 2026 at 5:29 PM Dmitri
> > > > > Bourlatchkov <
> > > > > >> > > > > > > > [email protected]
> > > > > >> > > > > > > > > >
> > > > > >> > > > > > > > > > > > wrote:
> > > > > >> > > > > > > > > > > >
> > > > > >> > > > > > > > > > > > > Hi EJ,
> > > > > >> > > > > > > > > > > > >
> > > > > >> > > > > > > > > > > > > Thanks for the summary! It covers what
> we
> > > > > >> discussed
> > > > > >> > in
> > > > > >> > > > the
> > > > > >> > > > > > > > meeting
> > > > > >> > > > > > > > > > very
> > > > > >> > > > > > > > > > > > > well, IMHO.
> > > > > >> > > > > > > > > > > > >
> > > > > >> > > > > > > > > > > > > Looking forward to concrete PRs :)
> > > > > >> > > > > > > > > > > > >
> > > > > >> > > > > > > > > > > > > Cheers,
> > > > > >> > > > > > > > > > > > > Dmitri.
> > > > > >> > > > > > > > > > > > >
> > > > > >> > > > > > > > > > > > > On Wed, May 6, 2026 at 5:08 PM EJ Wang <
> > > > > >> > > > > > > > > > [email protected]
> > > > > >> > > > > > > > > > > >
> > > > > >> > > > > > > > > > > > > wrote:
> > > > > >> > > > > > > > > > > > >
> > > > > >> > > > > > > > > > > > >> Hi folks,
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >> We had a community sync earlier, thanks
> > JB
> > > > for
> > > > > >> > > > scheduling
> > > > > >> > > > > > it.
> > > > > >> > > > > > > > > Notes
> > > > > >> > > > > > > > > > > from
> > > > > >> > > > > > > > > > > > >> the first metrics architecture sync
> (May
> > 6,
> > > > > >> 10-11am
> > > > > >> > > PT).
> > > > > >> > > > > > > > > Discussion
> > > > > >> > > > > > > > > > > doc
> > > > > >> > > > > > > > > > > > >> with per-section status:
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > >
> > > > > >> > > > > > > > > > >
> > > > > >> > > > > > > > > >
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > >
> > > > > >> > > > > > >
> > > > > >> > > > > >
> > > > > >> > > > >
> > > > > >> > > >
> > > > > >> > >
> > > > > >> >
> > > > > >>
> > > > >
> > > >
> >
> https://urldefense.com/v3/__https://docs.google.com/document/d/100h7c4damrUzVuquYbBHM0EvA4LSWuW2IT2dN_7nYVA/edit?tab=t.0__;!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrXgIddeUs$
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >> *The meeting covered both topics from
> the
> > > > doc.
> > > > > >> > > > > > Direction-level
> > > > > >> > > > > > > > > > > alignment
> > > > > >> > > > > > > > > > > > >> was reached on the headline pieces;
> > details
> > > > > >> remain
> > > > > >> > for
> > > > > >> > > > PR
> > > > > >> > > > > > > review
> > > > > >> > > > > > > > > or
> > > > > >> > > > > > > > > > > > >> follow-up sessions.*
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >> *Topic 1 — Persistence schema redesign*
> > > > > >> > > > > > > > > > > > >> Idea-level alignment on consolidating
> > > > per-type
> > > > > >> > tables
> > > > > >> > > > > > > > > > > > >> (scan_metrics_report,
> > > > > >> > > > > > > > > > > > >> commit_metrics_report) into a single
> > > > > >> metrics_report
> > > > > >> > > > table.
> > > > > >> > > > > > The
> > > > > >> > > > > > > > > > > > motivating
> > > > > >> > > > > > > > > > > > >> cost is the surface area added by every
> > new
> > > > > >> metric
> > > > > >> > > type
> > > > > >> > > > > > today:
> > > > > >> > > > > > > > new
> > > > > >> > > > > > > > > > > > table,
> > > > > >> > > > > > > > > > > > >> SPI method, record class, model,
> > converter,
> > > > > >> schema
> > > > > >> > > > > > migration.
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >> Most schema details are deferred to the
> > > > schema
> > > > > >> PR. A
> > > > > >> > > few
> > > > > >> > > > > > > > specific
> > > > > >> > > > > > > > > > > points
> > > > > >> > > > > > > > > > > > >> came up:
> > > > > >> > > > > > > > > > > > >> •   metric_schema_version: Yufei
> prefers
> > > > > dropping
> > > > > >> > it,
> > > > > >> > > > > since
> > > > > >> > > > > > > > there
> > > > > >> > > > > > > > > is
> > > > > >> > > > > > > > > > > no
> > > > > >> > > > > > > > > > > > >> spec-level concept of metrics
> versioning
> > > > today
> > > > > >> and
> > > > > >> > it
> > > > > >> > > is
> > > > > >> > > > > > hard
> > > > > >> > > > > > > to
> > > > > >> > > > > > > > > > > define
> > > > > >> > > > > > > > > > > > >> unilaterally. Robert prefers keeping
> it,
> > > > given
> > > > > >> IRC
> > > > > >> > v2
> > > > > >> > > is
> > > > > >> > > > > > > coming
> > > > > >> > > > > > > > > and
> > > > > >> > > > > > > > > > > the
> > > > > >> > > > > > > > > > > > >> schema should be considered against its
> > > > likely
> > > > > >> > shape;
> > > > > >> > > > > Robert
> > > > > >> > > > > > > > also
> > > > > >> > > > > > > > > > > raised
> > > > > >> > > > > > > > > > > > >> how to differentiate various payload
> > formats
> > > > if
> > > > > >> any.
> > > > > >> > > > EJ's
> > > > > >> > > > > > read
> > > > > >> > > > > > > > is
> > > > > >> > > > > > > > > > that
> > > > > >> > > > > > > > > > > > >> this
> > > > > >> > > > > > > > > > > > >> is a two-way-door decision. We can
> start
> > > > > without
> > > > > >> the
> > > > > >> > > > > field,
> > > > > >> > > > > > > and
> > > > > >> > > > > > > > if
> > > > > >> > > > > > > > > > IRC
> > > > > >> > > > > > > > > > > > v2
> > > > > >> > > > > > > > > > > > >> changes the shape we would likely roll
> a
> > > > > >> > corresponding
> > > > > >> > > > new
> > > > > >> > > > > > > > schema
> > > > > >> > > > > > > > > > > > anyway,
> > > > > >> > > > > > > > > > > > >> which is not particularly costly.
> > > > > >> > > > > > > > > > > > >> •   Payload format: Robert pointed out
> > that
> > > > > >> future
> > > > > >> > > > formats
> > > > > >> > > > > > > > beyond
> > > > > >> > > > > > > > > > JSON
> > > > > >> > > > > > > > > > > > may
> > > > > >> > > > > > > > > > > > >> be worth supporting. The exact shape is
> > > > > deferred
> > > > > >> to
> > > > > >> > > the
> > > > > >> > > > > > schema
> > > > > >> > > > > > > > > > > > discussion.
> > > > > >> > > > > > > > > > > > >> •   Partition strategy: Anand suggested
> > > > monthly
> > > > > >> > > > > partitioning
> > > > > >> > > > > > > > based
> > > > > >> > > > > > > > > > on
> > > > > >> > > > > > > > > > > > his
> > > > > >> > > > > > > > > > > > >> experience as potentially helpful at
> > scale.
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >> *Topic 2 — Where metrics ingestion and
> > > > storage
> > > > > >> > belong*
> > > > > >> > > > > > > > > > > > >> Idea-level alignment that metrics
> should
> > be a
> > > > > >> > > separated
> > > > > >> > > > > SPI
> > > > > >> > > > > > > from
> > > > > >> > > > > > > > > the
> > > > > >> > > > > > > > > > > > >> entity
> > > > > >> > > > > > > > > > > > >> persistence stack. Two reasons
> surfaced:
> > (a)
> > > > > >> > workloads
> > > > > >> > > > and
> > > > > >> > > > > > > > > > capability
> > > > > >> > > > > > > > > > > > >> requirements diverge enough that
> coupling
> > > > them
> > > > > >> > creates
> > > > > >> > > > > > > > artificial
> > > > > >> > > > > > > > > > > > >> constraints, and (b) admin experience
> > > > improves
> > > > > >> when
> > > > > >> > > > > metrics
> > > > > >> > > > > > > has
> > > > > >> > > > > > > > > its
> > > > > >> > > > > > > > > > > own
> > > > > >> > > > > > > > > > > > >> bootstrap, retention, and lifecycle.
> > Dmitri
> > > > > noted
> > > > > >> > > > Polaris
> > > > > >> > > > > > > being
> > > > > >> > > > > > > > a
> > > > > >> > > > > > > > > > > > platform
> > > > > >> > > > > > > > > > > > >> should have the flexibility to support
> > > > > different
> > > > > >> > > > > persistence
> > > > > >> > > > > > > > > > backends
> > > > > >> > > > > > > > > > > > per
> > > > > >> > > > > > > > > > > > >> concern, and pointed to a concrete next
> > step
> > > > of
> > > > > >> > > > separating
> > > > > >> > > > > > the
> > > > > >> > > > > > > > > JDBC
> > > > > >> > > > > > > > > > > > >> bootstrap for metrics from the
> metastore
> > > > > >> bootstrap.
> > > > > >> > > > Robert
> > > > > >> > > > > > > > > proposed
> > > > > >> > > > > > > > > > an
> > > > > >> > > > > > > > > > > > >> additional UX extension: detect an
> > > > > unbootstrapped
> > > > > >> > > > metrics
> > > > > >> > > > > > > store
> > > > > >> > > > > > > > on
> > > > > >> > > > > > > > > > > first
> > > > > >> > > > > > > > > > > > >> use and auto-bootstrap rather than
> > requiring
> > > > an
> > > > > >> > > explicit
> > > > > >> > > > > > > manual
> > > > > >> > > > > > > > > > > > bootstrap
> > > > > >> > > > > > > > > > > > >> step.
> > > > > >> > > > > > > > > > > > >> The meeting also confirmed that Polaris
> > > > metrics
> > > > > >> can
> > > > > >> > > > start
> > > > > >> > > > > > > small
> > > > > >> > > > > > > > > and
> > > > > >> > > > > > > > > > > stay
> > > > > >> > > > > > > > > > > > >> Iceberg-focused. Naming and persistence
> > > > schema
> > > > > >> can
> > > > > >> > > lean
> > > > > >> > > > > > > > > > > > Iceberg-specific.
> > > > > >> > > > > > > > > > > > >> If a future expansion to generic-table
> > > > metrics
> > > > > or
> > > > > >> > > > > > operational
> > > > > >> > > > > > > > > > metrics
> > > > > >> > > > > > > > > > > > >> arrives, an abstraction layer can be
> > built on
> > > > > >> top of
> > > > > >> > > the
> > > > > >> > > > > > > Iceberg
> > > > > >> > > > > > > > > > > metrics
> > > > > >> > > > > > > > > > > > >> reporter at that point. Robert remains
> > on the
> > > > > >> fence
> > > > > >> > > and
> > > > > >> > > > > > would
> > > > > >> > > > > > > > > prefer
> > > > > >> > > > > > > > > > > > >> something more generic but did not
> block
> > the
> > > > > >> > > direction;
> > > > > >> > > > > > > Dmitri's
> > > > > >> > > > > > > > > > read
> > > > > >> > > > > > > > > > > > was
> > > > > >> > > > > > > > > > > > >> that the proposed framework already has
> > > > enough
> > > > > >> > > > flexibility
> > > > > >> > > > > > to
> > > > > >> > > > > > > > > absorb
> > > > > >> > > > > > > > > > > > >> future
> > > > > >> > > > > > > > > > > > >> expansion.
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >> The Trade-offs and Proposed structure
> > > > sections
> > > > > in
> > > > > >> > the
> > > > > >> > > > doc
> > > > > >> > > > > > were
> > > > > >> > > > > > > > not
> > > > > >> > > > > > > > > > > > >> reviewed
> > > > > >> > > > > > > > > > > > >> in detail. They remain open for either
> > the
> > > > next
> > > > > >> sync
> > > > > >> > > or
> > > > > >> > > > PR
> > > > > >> > > > > > > > review.
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >> *Cross-cutting alignment —
> > battery-included
> > > > > plus
> > > > > >> > > > > pluggable*
> > > > > >> > > > > > > > > > > > >> A common philosophy emerged from the
> > > > > discussion.
> > > > > >> EJ
> > > > > >> > > > > > summarized
> > > > > >> > > > > > > > it
> > > > > >> > > > > > > > > > as:
> > > > > >> > > > > > > > > > > > >> Polaris should provide a
> > battery-included UX
> > > > > for
> > > > > >> > > > beginners
> > > > > >> > > > > > and
> > > > > >> > > > > > > > the
> > > > > >> > > > > > > > > > > > >> flexibility for advanced users to swap
> > the
> > > > > >> included
> > > > > >> > > > > battery
> > > > > >> > > > > > > for
> > > > > >> > > > > > > > > > > > something
> > > > > >> > > > > > > > > > > > >> more powerful or tailored to their use
> > case.
> > > > > The
> > > > > >> SPI
> > > > > >> > > > > design
> > > > > >> > > > > > > > needs
> > > > > >> > > > > > > > > to
> > > > > >> > > > > > > > > > > > >> enable
> > > > > >> > > > > > > > > > > > >> both.
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >> The inputs that shaped this framing:
> > > > > >> > > > > > > > > > > > >> •   Anand described how his team uses
> the
> > > > > current
> > > > > >> > > > metrics
> > > > > >> > > > > > > > > > persistence
> > > > > >> > > > > > > > > > > > >> (three metrics consumers in v1.4).
> > > > > >> > > > > > > > > > > > >> •   Yufei raised Grafana and dashboard
> > > > > >> integrations
> > > > > >> > > as a
> > > > > >> > > > > > > > > destination
> > > > > >> > > > > > > > > > > use
> > > > > >> > > > > > > > > > > > >> case beyond the default.
> > > > > >> > > > > > > > > > > > >> •   Robert called out that the current
> > design
> > > > > is
> > > > > >> > more
> > > > > >> > > > > > > > > JDBC-focused.
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >> Two concrete instances:
> > > > > >> > > > > > > > > > > > >> •   Async metrics intake: Yufei's
> initial
> > > > > >> position
> > > > > >> > was
> > > > > >> > > > > that
> > > > > >> > > > > > > > async
> > > > > >> > > > > > > > > > > should
> > > > > >> > > > > > > > > > > > >> largely live on the producer side and
> > there
> > > > is
> > > > > >> not
> > > > > >> > > much
> > > > > >> > > > > > > Polaris
> > > > > >> > > > > > > > > can
> > > > > >> > > > > > > > > > > do.
> > > > > >> > > > > > > > > > > > >> Robert suggested a Polaris-side default
> > is
> > > > > doable
> > > > > >> > via
> > > > > >> > > > > > Vert.x.
> > > > > >> > > > > > > > > Dmitri
> > > > > >> > > > > > > > > > > > >> agreed
> > > > > >> > > > > > > > > > > > >> the direction is worth exploring. The
> > meeting
> > > > > >> > > converged
> > > > > >> > > > > on a
> > > > > >> > > > > > > > > > > > >> battery-included default (likely
> > > > Vert.x-backed)
> > > > > >> with
> > > > > >> > > an
> > > > > >> > > > > SPI
> > > > > >> > > > > > > > shape
> > > > > >> > > > > > > > > > that
> > > > > >> > > > > > > > > > > > >> lets
> > > > > >> > > > > > > > > > > > >> power users route to a more scalable
> > backend
> > > > > >> > > (k8s-hosted
> > > > > >> > > > > > > queue,
> > > > > >> > > > > > > > > AWS
> > > > > >> > > > > > > > > > > SQS,
> > > > > >> > > > > > > > > > > > >> etc.).
> > > > > >> > > > > > > > > > > > >> •   Pluggable destinations: combining
> > Yufei's
> > > > > >> > > dashboard
> > > > > >> > > > > use
> > > > > >> > > > > > > case
> > > > > >> > > > > > > > > > with
> > > > > >> > > > > > > > > > > > >> Robert's JDBC-focused call-out, the
> > meeting
> > > > > >> agreed
> > > > > >> > the
> > > > > >> > > > SPI
> > > > > >> > > > > > > > should
> > > > > >> > > > > > > > > be
> > > > > >> > > > > > > > > > > > >> structured for multiple sinks so
> > integrations
> > > > > >> become
> > > > > >> > > > impl
> > > > > >> > > > > > > > choices
> > > > > >> > > > > > > > > > > rather
> > > > > >> > > > > > > > > > > > >> than architectural changes.
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >> The battery-included default is most
> > likely
> > > > to
> > > > > >> use
> > > > > >> > the
> > > > > >> > > > > > > existing
> > > > > >> > > > > > > > > > > > >> JDBC-backed
> > > > > >> > > > > > > > > > > > >> approach.
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >> *Direction (idea-level alignment)*
> > > > > >> > > > > > > > > > > > >> •   Single metrics_report table
> > consolidating
> > > > > >> > per-type
> > > > > >> > > > > > > metrics,
> > > > > >> > > > > > > > > > > > replacing
> > > > > >> > > > > > > > > > > > >> scan_metrics_report and
> > commit_metrics_report
> > > > > >> > > > > > > > > > > > >> •   Iceberg-focused naming and schema
> for
> > > > now,
> > > > > >> > revisit
> > > > > >> > > > if
> > > > > >> > > > > > > > > > > generic-table
> > > > > >> > > > > > > > > > > > or
> > > > > >> > > > > > > > > > > > >> operational metrics arrive
> > > > > >> > > > > > > > > > > > >> •   Metrics persistence as a separated
> > SPI,
> > > > not
> > > > > >> on
> > > > > >> > > > > > > > BasePersistence
> > > > > >> > > > > > > > > > > > >> •   Bootstrap path separated for
> metrics,
> > > > > >> > independent
> > > > > >> > > of
> > > > > >> > > > > > > > metastore
> > > > > >> > > > > > > > > > > > >> bootstrap
> > > > > >> > > > > > > > > > > > >> •   "Battery-included plus pluggable"
> as
> > the
> > > > > SPI
> > > > > >> > > design
> > > > > >> > > > > > > > philosophy
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >> *Open items*
> > > > > >> > > > > > > > > > > > >> •   Schema details:
> > metric_schema_version,
> > > > > >> payload
> > > > > >> > > > format,
> > > > > >> > > > > > IRC
> > > > > >> > > > > > > > v2
> > > > > >> > > > > > > > > > > > >> forward-compat shape
> > > > > >> > > > > > > > > > > > >> •   SPI design details — full review
> > either
> > > > in
> > > > > >> the
> > > > > >> > > next
> > > > > >> > > > > sync
> > > > > >> > > > > > > or
> > > > > >> > > > > > > > in
> > > > > >> > > > > > > > > > the
> > > > > >> > > > > > > > > > > > >> corresponding PR
> > > > > >> > > > > > > > > > > > >> •   Schema refactor PR ownership
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >> *Action items*
> > > > > >> > > > > > > > > > > > >> •   EJ to take a first stab at the SPI
> > design
> > > > > and
> > > > > >> > > > > > potentially
> > > > > >> > > > > > > > > > partner
> > > > > >> > > > > > > > > > > > with
> > > > > >> > > > > > > > > > > > >> Anand to incorporate the lessons
> learned
> > from
> > > > > the
> > > > > >> > > > existing
> > > > > >> > > > > > > > > reporter
> > > > > >> > > > > > > > > > > and
> > > > > >> > > > > > > > > > > > >> persistence work.
> > > > > >> > > > > > > > > > > > >> •   Schema refactor PR ownership is not
> > yet
> > > > > >> decided.
> > > > > >> > > If
> > > > > >> > > > > > anyone
> > > > > >> > > > > > > > is
> > > > > >> > > > > > > > > > > > >> interested in driving it, reply on this
> > > > thread.
> > > > > >> > > > > > > > > > > > >> •   JB to schedule the next sync,
> > tentatively
> > > > > in
> > > > > >> two
> > > > > >> > > > > weeks.
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >> -ej
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >> On Mon, Apr 27, 2026 at 3:07 PM EJ
> Wang <
> > > > > >> > > > > > > > > > > [email protected]
> > > > > >> > > > > > > > > > > > >
> > > > > >> > > > > > > > > > > > >> wrote:
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >> > Thanks Yufei for the +1.
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >> > JB, could you help add a biweekly
> > metrics
> > > > > >> > > architecture
> > > > > >> > > > > > sync
> > > > > >> > > > > > > to
> > > > > >> > > > > > > > > the
> > > > > >> > > > > > > > > > > > >> Polaris
> > > > > >> > > > > > > > > > > > >> > community calendar? I'm thinking
> > Thursdays
> > > > at
> > > > > >> > 9-10am
> > > > > >> > > > PT,
> > > > > >> > > > > > on
> > > > > >> > > > > > > > the
> > > > > >> > > > > > > > > > > > >> off-weeks
> > > > > >> > > > > > > > > > > > >> > from the community meeting (starting
> > May
> > > > 7),
> > > > > 60
> > > > > >> > > > minutes.
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >> > Here's a rough agenda to work through
> > over
> > > > > the
> > > > > >> > first
> > > > > >> > > > few
> > > > > >> > > > > > > > > sessions,
> > > > > >> > > > > > > > > > > > >> grouped
> > > > > >> > > > > > > > > > > > >> > by priority:
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >> > *First: foundational direction*
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >> > 1.  MetricsPersistence: public SPI or
> > > > > internal
> > > > > >> > > > > > > implementation
> > > > > >> > > > > > > > > > > detail?
> > > > > >> > > > > > > > > > > > >> >    •   Marked @Beta, javadoc calls
> it a
> > > > > >> "Service
> > > > > >> > > > > Provider
> > > > > >> > > > > > > > > > > Interface",
> > > > > >> > > > > > > > > > > > >> but
> > > > > >> > > > > > > > > > > > >> > only one consumer
> > > > (JdbcBasePersistenceImpl),
> > > > > >> lives
> > > > > >> > > on
> > > > > >> > > > > > > > > > > BasePersistence.
> > > > > >> > > > > > > > > > > > >> If
> > > > > >> > > > > > > > > > > > >> > demoted to a private helper inside a
> > > > > persisting
> > > > > >> > > > reporter
> > > > > >> > > > > > > impl,
> > > > > >> > > > > > > > > > most
> > > > > >> > > > > > > > > > > > >> > downstream design decisions become
> > > > > >> implementation
> > > > > >> > > > > details
> > > > > >> > > > > > > > rather
> > > > > >> > > > > > > > > > > than
> > > > > >> > > > > > > > > > > > >> > contract questions.
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >> > 2.  Persistence schema redesign
> > > > > >> > > > > > > > > > > > >> >    •   Current two-table layout
> > > > > >> > > (scan_metrics_report,
> > > > > >> > > > > > > > > > > > >> > commit_metrics_report) with ~25
> > flattened
> > > > > >> columns
> > > > > >> > > > each.
> > > > > >> > > > > > > Every
> > > > > >> > > > > > > > > new
> > > > > >> > > > > > > > > > > > metric
> > > > > >> > > > > > > > > > > > >> > type requires a new table, SPI
> method,
> > > > record
> > > > > >> > class,
> > > > > >> > > > > > model,
> > > > > >> > > > > > > > > > > converter,
> > > > > >> > > > > > > > > > > > >> and
> > > > > >> > > > > > > > > > > > >> > schema migration. Direction to
> explore:
> > > > > single
> > > > > >> > table
> > > > > >> > > > > with
> > > > > >> > > > > > > > > > > metric_type
> > > > > >> > > > > > > > > > > > >> enum,
> > > > > >> > > > > > > > > > > > >> > schema_version, and JSON payload
> > column.
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >> > *Second: design details once
> direction
> > is
> > > > > set*
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >> > 3.  Partition key strategy
> > > > > >> > > > > > > > > > > > >> >    •   Single-table design means scan
> > > > metrics
> > > > > >> at
> > > > > >> > > scale
> > > > > >> > > > > > will
> > > > > >> > > > > > > > have
> > > > > >> > > > > > > > > > > high
> > > > > >> > > > > > > > > > > > >> > write concurrency per table. Schema
> > needs
> > > > to
> > > > > >> > expose
> > > > > >> > > > > enough
> > > > > >> > > > > > > > > > structure
> > > > > >> > > > > > > > > > > > for
> > > > > >> > > > > > > > > > > > >> > backends to shard by entity or time
> > range.
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >> > 4.  Read/write path consistency
> > > > > >> > > > > > > > > > > > >> >    •   Writes go through
> > > > > PolarisMetricsManager
> > > > > >> on
> > > > > >> > > > > > > > > > MetaStoreManager.
> > > > > >> > > > > > > > > > > > >> Reads
> > > > > >> > > > > > > > > > > > >> > bypass MetaStoreManager and go
> > straight to
> > > > > >> > > > > > BasePersistence,
> > > > > >> > > > > > > > > > > excluding
> > > > > >> > > > > > > > > > > > >> > non-JDBC backends from the read API.
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >> > *Third: cleanup and alignment*
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >> > 5.  PolarisMetricsReporter naming
> > > > > >> > > > > > > > > > > > >> >    •   Only handles IRC
> > > > > >> (ScanReport/CommitReport),
> > > > > >> > > > > doesn't
> > > > > >> > > > > > > > cover
> > > > > >> > > > > > > > > > > > generic
> > > > > >> > > > > > > > > > > > >> > tables or operational metrics. Name
> is
> > > > > broader
> > > > > >> > than
> > > > > >> > > > > scope.
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >> > 6.  PolarisMetricsManager facade
> > > > passthrough
> > > > > >> > > > > > > > > > > > >> >    •   Entire default method is
> > > > > >> > > > > > > > > > > > >>
> callCtx.getMetaStore().writeScanReport().
> > > > > >> > > > > > > > > > > > >> > Zero logic, passes Level 1 straight
> > through
> > > > > to
> > > > > >> > Level
> > > > > >> > > > 3.
> > > > > >> > > > > > Same
> > > > > >> > > > > > > > > > > > >> anti-pattern
> > > > > >> > > > > > > > > > > > >> > as PolarisEventManager.
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >> > 7.  Iceberg community alignment
> > > > > >> > > > > > > > > > > > >> >    •   Payload-type extension needs
> > > > > discussion
> > > > > >> on
> > > > > >> > > > > > > dev@iceberg.
> > > > > >> > > > > > > > > > > > >> obelix74's
> > > > > >> > > > > > > > > > > > >> > Feb thread got zero replies. Needs a
> > > > > committer
> > > > > >> > > voice.
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >> > Lets confirm prioritization in the
> > first
> > > > > >> session.
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >> > -ej
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >> > On Tue, Apr 21, 2026 at 3:18 PM Yufei
> > Gu <
> > > > > >> > > > > > > > [email protected]>
> > > > > >> > > > > > > > > > > > wrote:
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >> >> Thanks everyone for continuing to
> > drive
> > > > this
> > > > > >> > > > forward. I
> > > > > >> > > > > > > agree
> > > > > >> > > > > > > > > > that
> > > > > >> > > > > > > > > > > > the
> > > > > >> > > > > > > > > > > > >> >> problem is getting complex enough
> > that a
> > > > > more
> > > > > >> > > > > structured
> > > > > >> > > > > > > > > > discussion
> > > > > >> > > > > > > > > > > > >> would
> > > > > >> > > > > > > > > > > > >> >> help.
> > > > > >> > > > > > > > > > > > >> >>
> > > > > >> > > > > > > > > > > > >> >> +1 on setting up a biweekly sync for
> > the
> > > > > >> metrics
> > > > > >> > > > > > > > architecture.
> > > > > >> > > > > > > > > > I’m
> > > > > >> > > > > > > > > > > > >> happy
> > > > > >> > > > > > > > > > > > >> >> to
> > > > > >> > > > > > > > > > > > >> >> join.
> > > > > >> > > > > > > > > > > > >> >>
> > > > > >> > > > > > > > > > > > >> >> Yufei
> > > > > >> > > > > > > > > > > > >> >>
> > > > > >> > > > > > > > > > > > >> >>
> > > > > >> > > > > > > > > > > > >> >> On Tue, Apr 21, 2026 at 2:34 PM EJ
> > Wang <
> > > > > >> > > > > > > > > > > > >> [email protected]>
> > > > > >> > > > > > > > > > > > >> >> wrote:
> > > > > >> > > > > > > > > > > > >> >>
> > > > > >> > > > > > > > > > > > >> >> > Also, I've been looking more
> > closely at
> > > > > the
> > > > > >> > > > > > *persistence
> > > > > >> > > > > > > > > schema
> > > > > >> > > > > > > > > > > in
> > > > > >> > > > > > > > > > > > >> the
> > > > > >> > > > > > > > > > > > >> >> > current metrics work*, and I think
> > > > > there's a
> > > > > >> > > > > structural
> > > > > >> > > > > > > > > > rigidity
> > > > > >> > > > > > > > > > > > >> problem
> > > > > >> > > > > > > > > > > > >> >> > worth raising before the shape
> gets
> > > > locked
> > > > > >> in.
> > > > > >> > > > > > > > > > > > >> >> >
> > > > > >> > > > > > > > > > > > >> >> > Right now we have two separate
> > tables
> > > > > >> > > > > > > (scan_metrics_report
> > > > > >> > > > > > > > > and
> > > > > >> > > > > > > > > > > > >> >> > commit_metrics_report), each with
> > ~25
> > > > > >> flattened
> > > > > >> > > > > columns
> > > > > >> > > > > > > > that
> > > > > >> > > > > > > > > > > > directly
> > > > > >> > > > > > > > > > > > >> >> > mirror the Iceberg report fields.
> > The
> > > > SPI
> > > > > >> > follows
> > > > > >> > > > the
> > > > > >> > > > > > > same
> > > > > >> > > > > > > > > > split:
> > > > > >> > > > > > > > > > > > >> >> > writeScanReport and
> > writeCommitReport as
> > > > > >> > separate
> > > > > >> > > > > > > methods,
> > > > > >> > > > > > > > > with
> > > > > >> > > > > > > > > > > > >> per-type
> > > > > >> > > > > > > > > > > > >> >> > record classes, converters, and
> > model
> > > > > >> objects.
> > > > > >> > > *The
> > > > > >> > > > > > > > practical
> > > > > >> > > > > > > > > > > cost:
> > > > > >> > > > > > > > > > > > >> >> > adding a new metric type
> > (operational
> > > > > >> metrics,
> > > > > >> > > for
> > > > > >> > > > > > > example)
> > > > > >> > > > > > > > > > > > requires
> > > > > >> > > > > > > > > > > > >> a
> > > > > >> > > > > > > > > > > > >> >> new
> > > > > >> > > > > > > > > > > > >> >> > table, a new SPI method, a new
> > record
> > > > > >> class, a
> > > > > >> > > new
> > > > > >> > > > > > model
> > > > > >> > > > > > > > > > class, a
> > > > > >> > > > > > > > > > > > new
> > > > > >> > > > > > > > > > > > >> >> > converter branch, and a schema
> > > > migration*.
> > > > > >> > > That's a
> > > > > >> > > > > lot
> > > > > >> > > > > > > of
> > > > > >> > > > > > > > > > > surface
> > > > > >> > > > > > > > > > > > >> area
> > > > > >> > > > > > > > > > > > >> >> > for what should be "one more kind
> of
> > > > > >> metric."
> > > > > >> > > > > > > > > > > > >> >> >
> > > > > >> > > > > > > > > > > > >> >> > *My bias* would be toward a single
> > > > metrics
> > > > > >> > table
> > > > > >> > > > with
> > > > > >> > > > > > *a
> > > > > >> > > > > > > > > typed
> > > > > >> > > > > > > > > > > JSON
> > > > > >> > > > > > > > > > > > >> >> > payload*. Something like:
> > metric_type
> > > > > >> (enum),
> > > > > >> > > > > > entity_id,
> > > > > >> > > > > > > > > > > > >> >> > table_identifier, snapshot_id
> > > > (nullable),
> > > > > >> > > > > received_ts,
> > > > > >> > > > > > > > > > > > >> schema_version,
> > > > > >> > > > > > > > > > > > >> >> and
> > > > > >> > > > > > > > > > > > >> >> > a payload column for the
> > metric-specific
> > > > > >> data.
> > > > > >> > > The
> > > > > >> > > > > > > > > metric_type
> > > > > >> > > > > > > > > > +
> > > > > >> > > > > > > > > > > > >> >> > schema_version pair gives us a
> > > > > >> > forward-compatible
> > > > > >> > > > > > > contract
> > > > > >> > > > > > > > > for
> > > > > >> > > > > > > > > > > the
> > > > > >> > > > > > > > > > > > >> >> payload
> > > > > >> > > > > > > > > > > > >> >> > shape. Adding a new metric type
> > becomes
> > > > an
> > > > > >> enum
> > > > > >> > > > value
> > > > > >> > > > > > > and a
> > > > > >> > > > > > > > > > > payload
> > > > > >> > > > > > > > > > > > >> >> schema,
> > > > > >> > > > > > > > > > > > >> >> > not a schema migration. One thing
> I
> > > > think
> > > > > we
> > > > > >> > need
> > > > > >> > > > to
> > > > > >> > > > > be
> > > > > >> > > > > > > > > > > deliberate
> > > > > >> > > > > > > > > > > > >> >> about is
> > > > > >> > > > > > > > > > > > >> >> > the partition key design. If all
> > metric
> > > > > >> types
> > > > > >> > > land
> > > > > >> > > > in
> > > > > >> > > > > > one
> > > > > >> > > > > > > > > > table,
> > > > > >> > > > > > > > > > > > scan
> > > > > >> > > > > > > > > > > > >> >> > metrics at scale (high
> concurrency,
> > high
> > > > > >> > > frequency
> > > > > >> > > > > > across
> > > > > >> > > > > > > > > many
> > > > > >> > > > > > > > > > > > >> tables)
> > > > > >> > > > > > > > > > > > >> >> > could easily create hot
> partitions.
> > We'd
> > > > > >> want
> > > > > >> > the
> > > > > >> > > > > > > > persistence
> > > > > >> > > > > > > > > > > layer
> > > > > >> > > > > > > > > > > > >> to
> > > > > >> > > > > > > > > > > > >> >> be
> > > > > >> > > > > > > > > > > > >> >> > able to shard by entity or time
> > range,
> > > > and
> > > > > >> that
> > > > > >> > > > means
> > > > > >> > > > > > the
> > > > > >> > > > > > > > > > logical
> > > > > >> > > > > > > > > > > > >> schema
> > > > > >> > > > > > > > > > > > >> >> > needs to expose enough structure
> for
> > > > > >> backends
> > > > > >> > to
> > > > > >> > > > > > > partition
> > > > > >> > > > > > > > > on.
> > > > > >> > > > > > > > > > I
> > > > > >> > > > > > > > > > > > >> don't
> > > > > >> > > > > > > > > > > > >> >> > think the current flattened layout
> > gives
> > > > > us
> > > > > >> > that.
> > > > > >> > > > > > > > > > > > >> >> >
> > > > > >> > > > > > > > > > > > >> >> > This is getting complex enough
> that
> > I
> > > > > don't
> > > > > >> > think
> > > > > >> > > > > > ad-hoc
> > > > > >> > > > > > > > > PR/ML
> > > > > >> > > > > > > > > > > > >> threads
> > > > > >> > > > > > > > > > > > >> >> > will converge well. *Would people
> be
> > > > open
> > > > > >> to a
> > > > > >> > > > > biweekly
> > > > > >> > > > > > > > sync
> > > > > >> > > > > > > > > > for
> > > > > >> > > > > > > > > > > > >> metrics
> > > > > >> > > > > > > > > > > > >> >> > architecture?* I think 30 minutes
> > every
> > > > > two
> > > > > >> > weeks
> > > > > >> > > > > with
> > > > > >> > > > > > > > > > interested
> > > > > >> > > > > > > > > > > > >> >> parties
> > > > > >> > > > > > > > > > > > >> >> > would be enough to work through
> the
> > > > > schema,
> > > > > >> SPI
> > > > > >> > > > > shape,
> > > > > >> > > > > > > and
> > > > > >> > > > > > > > > read
> > > > > >> > > > > > > > > > > API
> > > > > >> > > > > > > > > > > > >> >> design
> > > > > >> > > > > > > > > > > > >> >> > together. Happy to help set that
> up.
> > > > > >> > > > > > > > > > > > >> >> >
> > > > > >> > > > > > > > > > > > >> >> > -ej
> > > > > >> > > > > > > > > > > > >> >> >
> > > > > >> > > > > > > > > > > > >> >> > On Mon, Apr 20, 2026 at 2:19 PM EJ
> > Wang
> > > > <
> > > > > >> > > > > > > > > > > > >> [email protected]
> > > > > >> > > > > > > > > > > > >> >> >
> > > > > >> > > > > > > > > > > > >> >> > wrote:
> > > > > >> > > > > > > > > > > > >> >> >
> > > > > >> > > > > > > > > > > > >> >> >> Reviewed #4115, left a comment on
> > the
> > > > > code
> > > > > >> > > > > > organization
> > > > > >> > > > > > > > > side.
> > > > > >> > > > > > > > > > > > >> >> >>
> > > > > >> > > > > > > > > > > > >> >> >> One thing stood out: the metrics
> > write
> > > > > path
> > > > > >> > > enters
> > > > > >> > > > > > > through
> > > > > >> > > > > > > > > > > > >> >> >> PolarisMetricsManager on
> > > > > MetaStoreManager,
> > > > > >> but
> > > > > >> > > the
> > > > > >> > > > > new
> > > > > >> > > > > > > > read
> > > > > >> > > > > > > > > > path
> > > > > >> > > > > > > > > > > > >> >> bypasses
> > > > > >> > > > > > > > > > > > >> >> >> MetaStoreManager entirely and
> goes
> > > > > >> straight to
> > > > > >> > > > > > > > > BasePersistence
> > > > > >> > > > > > > > > > > via
> > > > > >> > > > > > > > > > > > >> >> >> callContext.getMetaStore(). That
> > means
> > > > > the
> > > > > >> > read
> > > > > >> > > > API
> > > > > >> > > > > > only
> > > > > >> > > > > > > > > works
> > > > > >> > > > > > > > > > > for
> > > > > >> > > > > > > > > > > > >> >> backends
> > > > > >> > > > > > > > > > > > >> >> >> that implement BasePersistence.
> > NoSQL
> > > > and
> > > > > >> > remote
> > > > > >> > > > > > > backends
> > > > > >> > > > > > > > > > can't
> > > > > >> > > > > > > > > > > > >> >> participate.
> > > > > >> > > > > > > > > > > > >> >> >>
> > > > > >> > > > > > > > > > > > >> >> >> Stepping back, I think the
> metrics
> > > > > >> subsystem
> > > > > >> > is
> > > > > >> > > > > > growing
> > > > > >> > > > > > > > into
> > > > > >> > > > > > > > > > > > >> something
> > > > > >> > > > > > > > > > > > >> >> >> real (write + read + REST API +
> > AuthZ +
> > > > > >> > > > pagination)
> > > > > >> > > > > > *but
> > > > > >> > > > > > > > the
> > > > > >> > > > > > > > > > > > >> >> persistence
> > > > > >> > > > > > > > > > > > >> >> >> side is split across two layers
> in
> > a
> > > > way
> > > > > >> > that's
> > > > > >> > > > hard
> > > > > >> > > > > > to
> > > > > >> > > > > > > > > > > extend*. I
> > > > > >> > > > > > > > > > > > >> put
> > > > > >> > > > > > > > > > > > >> >> >> together two diagrams to show
> what
> > I
> > > > mean
> > > > > >> (my
> > > > > >> > > best
> > > > > >> > > > > > > > effort).
> > > > > >> > > > > > > > > > > > >> >> >>
> > > > > >> > > > > > > > > > > > >> >> >> *Current state* (Diagram 1):
> three
> > > > > >> interfaces
> > > > > >> > at
> > > > > >> > > > > three
> > > > > >> > > > > > > > > > different
> > > > > >> > > > > > > > > > > > >> >> levels.
> > > > > >> > > > > > > > > > > > >> >> >> The engine-facing SPI
> > > > > >> (PolarisMetricsReporter)
> > > > > >> > > is
> > > > > >> > > > > > clean.
> > > > > >> > > > > > > > But
> > > > > >> > > > > > > > > > > > >> >> >> PolarisMetricsManager on
> > > > MetaStoreManager
> > > > > >> is a
> > > > > >> > > > > > > passthrough
> > > > > >> > > > > > > > > to
> > > > > >> > > > > > > > > > > > >> >> >> MetricsPersistence on
> > BasePersistence.
> > > > > The
> > > > > >> > @Beta
> > > > > >> > > > > > > > annotation
> > > > > >> > > > > > > > > > and
> > > > > >> > > > > > > > > > > > SPI
> > > > > >> > > > > > > > > > > > >> >> javadoc
> > > > > >> > > > > > > > > > > > >> >> >> are on the BasePersistence layer,
> > while
> > > > > the
> > > > > >> > > actual
> > > > > >> > > > > > > > extension
> > > > > >> > > > > > > > > > > > points
> > > > > >> > > > > > > > > > > > >> >> >> (PolarisMetricsReporter,
> > > > > >> > PolarisMetricsManager)
> > > > > >> > > > > carry
> > > > > >> > > > > > no
> > > > > >> > > > > > > > > > > stability
> > > > > >> > > > > > > > > > > > >> >> >> annotation. The write path goes
> > through
> > > > > the
> > > > > >> > > > > > > > MetaStoreManager
> > > > > >> > > > > > > > > > > > layer,
> > > > > >> > > > > > > > > > > > >> the
> > > > > >> > > > > > > > > > > > >> >> >> read path doesn't.
> > > > > >> > > > > > > > > > > > >> >> >>
> > > > > >> > > > > > > > > > > > >> >> >> *What I envision* (Diagram 2):
> two
> > SPIs
> > > > > at
> > > > > >> two
> > > > > >> > > > > levels.
> > > > > >> > > > > > > > > > > > >> >> >> PolarisMetricsReporter stays as
> the
> > > > > >> > > engine-facing
> > > > > >> > > > > SPI.
> > > > > >> > > > > > > > > > > > >> >> >> PolarisMetricsManager becomes the
> > > > > >> > backend-facing
> > > > > >> > > > SPI
> > > > > >> > > > > > > with
> > > > > >> > > > > > > > > both
> > > > > >> > > > > > > > > > > > write
> > > > > >> > > > > > > > > > > > >> >> and
> > > > > >> > > > > > > > > > > > >> >> >> read methods at the
> > MetaStoreManager
> > > > > level,
> > > > > >> > > where
> > > > > >> > > > > any
> > > > > >> > > > > > > > > backend
> > > > > >> > > > > > > > > > > > (JDBC,
> > > > > >> > > > > > > > > > > > >> >> NoSQL,
> > > > > >> > > > > > > > > > > > >> >> >> remote) can implement them.
> > > > > >> MetricsPersistence
> > > > > >> > > on
> > > > > >> > > > > > > > > > > BasePersistence
> > > > > >> > > > > > > > > > > > >> goes
> > > > > >> > > > > > > > > > > > >> >> >> away. Where metrics actually land
> > is an
> > > > > >> > > > > implementation
> > > > > >> > > > > > > > > detail,
> > > > > >> > > > > > > > > > > > not a
> > > > > >> > > > > > > > > > > > >> >> core
> > > > > >> > > > > > > > > > > > >> >> >> interface.
> > > > > >> > > > > > > > > > > > >> >> >>
> > > > > >> > > > > > > > > > > > >> >> >> *Minor naming thing*:
> > > > > >> PolarisMetricsReporter
> > > > > >> > is
> > > > > >> > > > > > broader
> > > > > >> > > > > > > > than
> > > > > >> > > > > > > > > > > what
> > > > > >> > > > > > > > > > > > it
> > > > > >> > > > > > > > > > > > >> >> >> actually handles. It only accepts
> > > > Iceberg
> > > > > >> REST
> > > > > >> > > > > Catalog
> > > > > >> > > > > > > > > metrics
> > > > > >> > > > > > > > > > > > >> >> (ScanReport,
> > > > > >> > > > > > > > > > > > >> >> >> CommitReport via MetricsReport).
> > > > Generic
> > > > > >> table
> > > > > >> > > > > metrics
> > > > > >> > > > > > > or
> > > > > >> > > > > > > > > > > > >> operational
> > > > > >> > > > > > > > > > > > >> >> >> metrics aren't in scope. Not
> > blocking,
> > > > > but
> > > > > >> > worth
> > > > > >> > > > > > noting
> > > > > >> > > > > > > if
> > > > > >> > > > > > > > > the
> > > > > >> > > > > > > > > > > > >> metrics
> > > > > >> > > > > > > > > > > > >> >> >> surface expands.
> > > > > >> > > > > > > > > > > > >> >> >>
> > > > > >> > > > > > > > > > > > >> >> >> *Rough sketch of how to get
> there*:
> > > > > >> > > > > > > > > > > > >> >> >>  1.  Add read methods to
> > > > > >> PolarisMetricsManager
> > > > > >> > > > > > > > > > (listScanReports,
> > > > > >> > > > > > > > > > > > >> >> >> listCommitReports) with default
> > no-op,
> > > > > >> same as
> > > > > >> > > the
> > > > > >> > > > > > > > existing
> > > > > >> > > > > > > > > > > write
> > > > > >> > > > > > > > > > > > >> >> methods.
> > > > > >> > > > > > > > > > > > >> >> >> (Probably make
> > PolarisMetricsManager
> > > > more
> > > > > >> > > explicit
> > > > > >> > > > > on
> > > > > >> > > > > > > > being
> > > > > >> > > > > > > > > > > > Iceberg
> > > > > >> > > > > > > > > > > > >> >> >> specific like package name or
> class
> > > > name
> > > > > >> etc.)
> > > > > >> > > > > > > > > > > > >> >> >>  2.  Wire MetricsReportsService
> > through
> > > > > >> > > > > > MetaStoreManager
> > > > > >> > > > > > > > > > instead
> > > > > >> > > > > > > > > > > > of
> > > > > >> > > > > > > > > > > > >> >> >> callContext.getMetaStore().
> > > > > >> > > > > > > > > > > > >> >> >>  3.  Extract metrics persistence
> > from
> > > > > >> > > > > > > > > JdbcBasePersistenceImpl
> > > > > >> > > > > > > > > > > into
> > > > > >> > > > > > > > > > > > >> its
> > > > > >> > > > > > > > > > > > >> >> >> own class. That file carries ~7
> > > > > >> > > responsibilities,
> > > > > >> > > > > > > metrics
> > > > > >> > > > > > > > > > being
> > > > > >> > > > > > > > > > > > one
> > > > > >> > > > > > > > > > > > >> of
> > > > > >> > > > > > > > > > > > >> >> them.
> > > > > >> > > > > > > > > > > > >> >> >>  4.  Remove MetricsPersistence
> from
> > > > > >> > > > BasePersistence.
> > > > > >> > > > > > > > > > > > >> >> >>
> > > > > >> > > > > > > > > > > > >> >> >> *None of this needs to happen in
> > #4115.
> > > > > >> But if
> > > > > >> > > the
> > > > > >> > > > > > > > direction
> > > > > >> > > > > > > > > > > makes
> > > > > >> > > > > > > > > > > > >> >> sense,
> > > > > >> > > > > > > > > > > > >> >> >> it would be good to align before
> > the
> > > > > >> metrics
> > > > > >> > > > surface
> > > > > >> > > > > > > grows
> > > > > >> > > > > > > > > > > > further.
> > > > > >> > > > > > > > > > > > >> >> Curious
> > > > > >> > > > > > > > > > > > >> >> >> what others think.*
> > > > > >> > > > > > > > > > > > >> >> >>
> > > > > >> > > > > > > > > > > > >> >> >> *My mental model note*: Level 1
> > > > > >> > > MetaStoreManager;
> > > > > >> > > > > > level
> > > > > >> > > > > > > 2
> > > > > >> > > > > > > > > > > > >> transactional
> > > > > >> > > > > > > > > > > > >> >> >> persistence; level 3 base
> > persistence
> > > > > >> > > > > > > > > > > > >> >> >>
> > > > > >> > > > > > > > > > > > >> >> >> Diagram 1
> > > > > >> > > > > > > > > > > > >> >> >> <
> > > > > >> > > > > > > > > > > > >> >>
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > >
> > > > > >> > > > > > > > > > >
> > > > > >> > > > > > > > > >
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > >
> > > > > >> > > > > > >
> > > > > >> > > > > >
> > > > > >> > > > >
> > > > > >> > > >
> > > > > >> > >
> > > > > >> >
> > > > > >>
> > > > >
> > > >
> >
> https://urldefense.com/v3/__https://www.plantuml.com/plantuml/uml/bLHDR-Cs4BthLmpIYupw0zbkKQ1r3M-S7Bp8xhhM7WCOb3IM65EaGD9EX2RzxHrHb4CxRelwa4YSDu_lpOVcnZ9jzvM8BBS2uGjQpJC3dtHMSekPtMk44IpsMgEqa5XcCOhCZikQQLP1pR8TAp2n3ILhmZDP20m0fcIvUkAoW2qJXd9z1bpToO9BX3WXu0ucy5rpgGPNm0nW5_epUWtm2Ue3pn3kMOFQmKntGZW0BYtgBSi8k5A2QMwybJNMIbFiGSR9QZc4nUqIvikStF0jHprua5C-amge42aNt3R0f5JaaoivdV2Pkqbx4hee4ymOkBh5BTiB-_uIeGeo8zL8rPsPl4DktdEiK1jkB1NdZCRbrSTecDe_mlHbF0wvBmCkaOH5_S8a_TTTKI6-nmCAkEw4LpxsZ-LbYLKQFKMNOgf_wuM7_bV9gOer5SYMMksBSWXFcbi49KNZXNLicwfe3TETC7gPdPqI7uBcHMb1RSzYq34c6PDUM9mn8HRsUTZEiDBve3NjVZumBj0U7SS37mGO7vcwtiK-_pU7U7L_f-digo9YbhSwIfMRwIITKGXbxdIUTCGF1SeCJxloKsU-3k9ddRbX1eDq1q_fx1JbBGT0glVyXimDuP4TQ5qpCAmnGEj2s_6n5mtn1z-97-63itFQZLPO1Ev2tu_WF7Ju-VPc0Skg5bYXxBhkY1xpD7EM_7fyflSpIsqMgVth5xhVr4eQxWQ8enaSAJQSG16yFSDuJ798rrcXr_3n-lfdk7icQjEBmFujL7AodiP_Y4Z7-YxvtZNs4zMgpNTl6tF8sglyPsmqchrjvQ-m-aP94r-TwCA2Ka8upPJZwtvSpoYCXkYMZU2NXvRMBfq9P3i3Le4VAZUAlUZ_oPKsxPgY0Q_BSKLkyr9bhQhQrJjo_x3TPlIB0DPjnMfcIoYP0QaYw1a0fTKDr8fB6ntNuvmoL1ZGkXa69Njh43zf9GiGxHQrA_jDYWRSzF5--WmTVrN97_Sm8LbLUy_lGBmLanJjFkDlGkRqjA_4tm00__;!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrXuTBISHg$
> > > > > >> > > > > > > > > > > > >> >> >
> > > > > >> > > > > > > > > > > > >> >> >> :
> > > > > >> > > > > > > > > > > > >> >> >>
> > > > > >> > > > > > > > > > > > >> >> >> [image: image.png]
> > > > > >> > > > > > > > > > > > >> >> >>
> > > > > >> > > > > > > > > > > > >> >> >> Diagram 2
> > > > > >> > > > > > > > > > > > >> >> >> <
> > > > > >> > > > > > > > > > > > >> >>
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > >
> > > > > >> > > > > > > > > > >
> > > > > >> > > > > > > > > >
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > >
> > > > > >> > > > > > >
> > > > > >> > > > > >
> > > > > >> > > > >
> > > > > >> > > >
> > > > > >> > >
> > > > > >> >
> > > > > >>
> > > > >
> > > >
> >
> https://urldefense.com/v3/__https://www.plantuml.com/plantuml/uml/VLLDR-8m4BtdLupO2sWBLVU8AaGB7AXAbssGzb896SS9RXqxjKqBwkv_tt7iV43fdaZYDpFlpRmnOsE9jhjSH9PRmM31hERKm8scMsuPjJlDe0yheZDc8RR4iYWoBrmMH9CS2a9VICPYUy1OZN0YCy5Q0BCbYNhdCeEK28En8G8wCvbnoQ0R8_05Bc6bkLIz3X03p1zzH7zR-9ZfDquPt9C3qoNCX2yV4G2NbkcKu5jdgGJHt0GbZwnG6i-UP3TUpk5gM6Ldqke350eZUqzoCft3U9xWHvxoa5-7K4nF1J46EbEMafsmdrCBbQ44gVggy18IZrn_ph5asd1ZiIKdQSgueZvjXrQFSFrdC3YN-nXmBacxbGiYyLVxLaBtdhqn0LSzdBDhqQtQoOJeGyad3z0lUqnYgpGB6Ns8oVyta00Dy_WnX0tIOZ8v6SYxHll1TrH6aejAik-mh-AphVFCwSUQqFypElag5QRGFDjQKEd96K1P8QP41c9TzA_IIQyvdAWyv_RSiS3skb0_EzDDkK2v5xWF6MiGFlvhpFLcD2Dq2pml14gaF67eQkmd8gulDoC4kSOu6KVpkvlUJg1RTbWISU40RdBUUS_9XfRZ2dwxm_SW8LYFISgm_MnlDQ6M9P1gbKEc4X-2pH_FvJCkCqm9pbVjD6LrwdLeOrDWfOaqc8Wh9BE85oNKxkNQ6o4yGRy_Eae0G_G8tZv81d3bHDB23WOdisohVr3nh_j6lbSjbNaLRTc8UgtPbAU1J_tygOfZX9DWEJeHDvYx-qmSi5FgNLPZwHrHcUsncGQ5-skhUclpE5fo4ounpFauYrUbkU6ccfnxMvitwag4IyerhTxj8In_Oj1bDO4pQru674loYrGlULHLEGCjwJJ8gDoVZR8MxO4BT3IzRvIcAQKezC6xpziGnTyImrfEGyJI_OcKfgtxIvnTqFEMS17L9Z-jsARN5FmTheP7HtSdtOMT0B4GY2FYHXxgQmMtj2bRqiLFGapiVe1_QVKDrkqXcm83aFEXnMYCZ-xlyHy__;!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrXSpmqcNk$
> > > > > >> > > > > > > > > > > > >> >> >
> > > > > >> > > > > > > > > > > > >> >> >> :
> > > > > >> > > > > > > > > > > > >> >> >> [image: image.png]
> > > > > >> > > > > > > > > > > > >> >> >>
> > > > > >> > > > > > > > > > > > >> >> >>  -ej
> > > > > >> > > > > > > > > > > > >> >> >>
> > > > > >> > > > > > > > > > > > >> >> >> On Wed, Apr 15, 2026 at 8:22 AM
> > Dmitri
> > > > > >> > > > Bourlatchkov
> > > > > >> > > > > <
> > > > > >> > > > > > > > > > > > >> [email protected]>
> > > > > >> > > > > > > > > > > > >> >> >> wrote:
> > > > > >> > > > > > > > > > > > >> >> >>
> > > > > >> > > > > > > > > > > > >> >> >>> Hi All,
> > > > > >> > > > > > > > > > > > >> >> >>>
> > > > > >> > > > > > > > > > > > >> >> >>> Heads up: The current state of
> PR
> > > > [4115]
> > > > > >> > looks
> > > > > >> > > > > pretty
> > > > > >> > > > > > > > solid
> > > > > >> > > > > > > > > > to
> > > > > >> > > > > > > > > > > > me.
> > > > > >> > > > > > > > > > > > >> I
> > > > > >> > > > > > > > > > > > >> >> >>> believe this PR is approaching a
> > > > > mergeable
> > > > > >> > > > > condition.
> > > > > >> > > > > > > > > > > > >> >> >>>
> > > > > >> > > > > > > > > > > > >> >> >>> Please post your reviews if you
> > have
> > > > any
> > > > > >> > > > comments.
> > > > > >> > > > > > > > > > > > >> >> >>>
> > > > > >> > > > > > > > > > > > >> >> >>> [4115]
> > > > > >> > > >
> https://urldefense.com/v3/__https://github.com/apache/polaris/pull/4115__;!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrXtFRscKs$
> > > > > >> > > > > > > > > > > > >> >> >>>
> > > > > >> > > > > > > > > > > > >> >> >>> Thanks,
> > > > > >> > > > > > > > > > > > >> >> >>> Dmitri.
> > > > > >> > > > > > > > > > > > >> >> >>>
> > > > > >> > > > > > > > > > > > >> >> >>> On Tue, Mar 3, 2026 at 3:29 PM
> > Anand
> > > > > Kumar
> > > > > >> > > > Sankaran
> > > > > >> > > > > > via
> > > > > >> > > > > > > > > dev <
> > > > > >> > > > > > > > > > > > >> >> >>> [email protected]> wrote:
> > > > > >> > > > > > > > > > > > >> >> >>>
> > > > > >> > > > > > > > > > > > >> >> >>> > Hi Yufei and Dmitri,
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> > Here is a proposal for the
> REST
> > > > > >> endpoints
> > > > > >> > for
> > > > > >> > > > > > metrics
> > > > > >> > > > > > > > and
> > > > > >> > > > > > > > > > > > events.
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > >
> https://urldefense.com/v3/__https://github.com/apache/polaris/pull/3924/changes__;!!Iz9xO38YGHZK!4rnlVIqBQQQ6xpGe1PMV58edOS_cGrKoqdfhw4qSp_JQCavvEjaxXk0OwGPnxyEcO60AzKQK_XDtp7H3DdkFXcrXcjoPhSs$
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> > I did not see any precursors
> for
> > > > > >> raising a
> > > > > >> > PR
> > > > > >> > > > for
> > > > > >> > > > > > > > > > proposals,
> > > > > >> > > > > > > > > > > so
> > > > > >> > > > > > > > > > > > >> >> trying
> > > > > >> > > > > > > > > > > > >> >> >>> > this.  Please let me know what
> > you
> > > > > >> think.
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> > -
> > > > > >> > > > > > > > > > > > >> >> >>> > Anand
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> > From: Anand Kumar Sankaran <
> > > > > >> > > > > > > [email protected]
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > > > > > > >> >> >>> > Date: Monday, March 2, 2026 at
> > > > > 10:25 AM
> > > > > >> > > > > > > > > > > > >> >> >>> > To: [email protected] <
> > > > > >> > > > > [email protected]
> > > > > >> > > > > > >
> > > > > >> > > > > > > > > > > > >> >> >>> > Subject: Re: Polaris Telemetry
> > and
> > > > > Audit
> > > > > >> > > Trail
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> > About the REST API, based on
> my
> > use
> > > > > >> cases:
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> >   1.
> > > > > >> > > > > > > > > > > > >> >> >>> > I want to be able to query
> > commit
> > > > > >> metrics
> > > > > >> > to
> > > > > >> > > > > track
> > > > > >> > > > > > > > files
> > > > > >> > > > > > > > > > > added
> > > > > >> > > > > > > > > > > > /
> > > > > >> > > > > > > > > > > > >> >> >>> removed
> > > > > >> > > > > > > > > > > > >> >> >>> > per commit, along with record
> > > > counts.
> > > > > >> The
> > > > > >> > > > > ingestion
> > > > > >> > > > > > > > > > pipeline
> > > > > >> > > > > > > > > > > > that
> > > > > >> > > > > > > > > > > > >> >> >>> writes
> > > > > >> > > > > > > > > > > > >> >> >>> > this data is owned by us and
> we
> > are
> > > > > >> > > guaranteed
> > > > > >> > > > to
> > > > > >> > > > > > > write
> > > > > >> > > > > > > > > > this
> > > > > >> > > > > > > > > > > > >> >> >>> information
> > > > > >> > > > > > > > > > > > >> >> >>> > for each write.
> > > > > >> > > > > > > > > > > > >> >> >>> >   2.
> > > > > >> > > > > > > > > > > > >> >> >>> > I want to be able to query
> scan
> > > > > metrics
> > > > > >> for
> > > > > >> > > > > read. I
> > > > > >> > > > > > > > > > > understand
> > > > > >> > > > > > > > > > > > >> >> clients
> > > > > >> > > > > > > > > > > > >> >> >>> do
> > > > > >> > > > > > > > > > > > >> >> >>> > not fulfill this requirement.
> > > > > >> > > > > > > > > > > > >> >> >>> >   3.
> > > > > >> > > > > > > > > > > > >> >> >>> > I want to be able to query the
> > > > events
> > > > > >> table
> > > > > >> > > > > (events
> > > > > >> > > > > > > are
> > > > > >> > > > > > > > > > > > >> persisted) -
> > > > > >> > > > > > > > > > > > >> >> >>> this
> > > > > >> > > > > > > > > > > > >> >> >>> > may supersede #2, I am not
> sure
> > yet.
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> > All this information is in the
> > JDBC
> > > > > >> based
> > > > > >> > > > > > persistence
> > > > > >> > > > > > > > > model
> > > > > >> > > > > > > > > > > and
> > > > > >> > > > > > > > > > > > >> is
> > > > > >> > > > > > > > > > > > >> >> >>> > persisted in the metastore. I
> > > > > currently
> > > > > >> > don’t
> > > > > >> > > > > have
> > > > > >> > > > > > a
> > > > > >> > > > > > > > need
> > > > > >> > > > > > > > > > to
> > > > > >> > > > > > > > > > > > >> query
> > > > > >> > > > > > > > > > > > >> >> >>> > prometheus or open telemetry.
> I
> > do
> > > > > >> publish
> > > > > >> > > some
> > > > > >> > > > > > > events
> > > > > >> > > > > > > > to
> > > > > >> > > > > > > > > > > > >> Prometheus
> > > > > >> > > > > > > > > > > > >> >> >>> and
> > > > > >> > > > > > > > > > > > >> >> >>> > they are forwarded to our
> > dashboards
> > > > > >> > > elsewhere.
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> > About the CLI utilities, I
> > meant the
> > > > > >> admin
> > > > > >> > > user
> > > > > >> > > > > > > > > utilities.
> > > > > >> > > > > > > > > > In
> > > > > >> > > > > > > > > > > > >> one of
> > > > > >> > > > > > > > > > > > >> >> >>> the
> > > > > >> > > > > > > > > > > > >> >> >>> > earliest drafts of my
> proposal,
> > > > > Prashant
> > > > > >> > > > > mentioned
> > > > > >> > > > > > > that
> > > > > >> > > > > > > > > the
> > > > > >> > > > > > > > > > > > >> metrics
> > > > > >> > > > > > > > > > > > >> >> >>> tables
> > > > > >> > > > > > > > > > > > >> >> >>> > can grow indefinitely and
> that a
> > > > > similar
> > > > > >> > > > problem
> > > > > >> > > > > > > exists
> > > > > >> > > > > > > > > > with
> > > > > >> > > > > > > > > > > > the
> > > > > >> > > > > > > > > > > > >> >> events
> > > > > >> > > > > > > > > > > > >> >> >>> > table as well. We discussed
> that
> > > > > >> cleaning
> > > > > >> > up
> > > > > >> > > of
> > > > > >> > > > > old
> > > > > >> > > > > > > > > records
> > > > > >> > > > > > > > > > > > from
> > > > > >> > > > > > > > > > > > >> >> both
> > > > > >> > > > > > > > > > > > >> >> >>> > metrics tables and events
> > tables can
> > > > > be
> > > > > >> > done
> > > > > >> > > > via
> > > > > >> > > > > a
> > > > > >> > > > > > > CLI
> > > > > >> > > > > > > > > > > utility.
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> > I see that Yufei has covered
> the
> > > > > >> discussion
> > > > > >> > > > about
> > > > > >> > > > > > > > > > > datasources.
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> > -
> > > > > >> > > > > > > > > > > > >> >> >>> > Anand
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> > From: Yufei Gu <
> > > > [email protected]>
> > > > > >> > > > > > > > > > > > >> >> >>> > Date: Friday, February 27,
> 2026
> > at
> > > > > >> 9:54 PM
> > > > > >> > > > > > > > > > > > >> >> >>> > To: [email protected] <
> > > > > >> > > > > [email protected]
> > > > > >> > > > > > >
> > > > > >> > > > > > > > > > > > >> >> >>> > Subject: Re: Polaris Telemetry
> > and
> > > > > Audit
> > > > > >> > > Trail
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> > This Message Is From an
> External
> > > > > Sender
> > > > > >> > > > > > > > > > > > >> >> >>> > This message came from outside
> > your
> > > > > >> > > > organization.
> > > > > >> > > > > > > > > > > > >> >> >>> > Report Suspicious<
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>>
> > > > > >> > > > > > > > > > > > >> >>
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > >
> > > > > >> > > > > > > > > > >
> > > > > >> > > > > > > > > >
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > >
> > > > > >> > > > > > >
> > > > > >> > > > > >
> > > > > >> > > > >
> > > > > >> > > >
> > > > > >> > >
> > > > > >> >
> > > > > >>
> > > > >
> > > >
> >
> https://us-phishalarm-ewt.proofpoint.com/EWT/v1/Iz9xO38YGHZK!YhNDZABkHi1B699ote2uMwpOZw8i0QMCGO2Szc-HshuABGhGvwPJcymE6G2oUUxtS8xDkSrtGTPm_I3QnVDHoLMk50m9v8z_nZKTkd-bnVUbreF1u0WnfV_X5eYevZl_$
> > > > > >> > > > > > > > > > > > >> >> >>> > >
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> > As I mentioned in
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>>
> > > > > >> > > > > > > > > > > > >> >>
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > >
> > > > > >> > > > > > > > > > >
> > > > > >> > > > > > > > > >
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > >
> > > > > >> > > > > > >
> > > > > >> > > > > >
> > > > > >> > > > >
> > > > > >> > > >
> > > > > >> > >
> > > > > >> >
> > > > > >>
> > > > >
> > > >
> >
> https://urldefense.com/v3/__https://github.com/apache/polaris/issues/3890__;!!Iz9xO38YGHZK!5EuyFFkk3vhRWVIRvQAWBSQfpJkTMA9HxugzDwXmN0LPPqhEFxYkFRGVhtb8AqUwXtDh2OplcMnbMDHKOxrvDU0$
> >> > > >> > > > > > > > > > > > >> >> >>> ,
> > > > > >> > > > > > > > > > > > >> >> >>> > supporting
> > > > > >> > > > > > > > > > > > >> >> >>> > multiple data sources is not a
> > > > trivial
> > > > > >> > > change.
> > > > > >> > > > I
> > > > > >> > > > > > > would
> > > > > >> > > > > > > > > > > strongly
> > > > > >> > > > > > > > > > > > >> >> >>> recommend
> > > > > >> > > > > > > > > > > > >> >> >>> > starting with a design
> document
> > to
> > > > > >> > carefully
> > > > > >> > > > > > evaluate
> > > > > >> > > > > > > > the
> > > > > >> > > > > > > > > > > > >> >> architectural
> > > > > >> > > > > > > > > > > > >> >> >>> > implications and long term
> > impact.
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> > A REST endpoint to query
> metrics
> > > > seems
> > > > > >> > > > reasonable
> > > > > >> > > > > > > given
> > > > > >> > > > > > > > > the
> > > > > >> > > > > > > > > > > > >> current
> > > > > >> > > > > > > > > > > > >> >> >>> JDBC
> > > > > >> > > > > > > > > > > > >> >> >>> > based persistence model. That
> > said,
> > > > we
> > > > > >> may
> > > > > >> > > also
> > > > > >> > > > > > > > consider
> > > > > >> > > > > > > > > > > > >> alternative
> > > > > >> > > > > > > > > > > > >> >> >>> > storage models. For example,
> if
> > we
> > > > > later
> > > > > >> > > adopt
> > > > > >> > > > a
> > > > > >> > > > > > time
> > > > > >> > > > > > > > > > series
> > > > > >> > > > > > > > > > > > >> system
> > > > > >> > > > > > > > > > > > >> >> >>> such as
> > > > > >> > > > > > > > > > > > >> >> >>> > Prometheus to store metrics,
> the
> > > > query
> > > > > >> > model
> > > > > >> > > > and
> > > > > >> > > > > > > access
> > > > > >> > > > > > > > > > > > patterns
> > > > > >> > > > > > > > > > > > >> >> would
> > > > > >> > > > > > > > > > > > >> >> >>> be
> > > > > >> > > > > > > > > > > > >> >> >>> > fundamentally different.
> > Designing
> > > > the
> > > > > >> REST
> > > > > >> > > API
> > > > > >> > > > > > > without
> > > > > >> > > > > > > > > > > > >> considering
> > > > > >> > > > > > > > > > > > >> >> >>> these
> > > > > >> > > > > > > > > > > > >> >> >>> > potential evolutions may limit
> > > > > >> flexibility.
> > > > > >> > > I'd
> > > > > >> > > > > > > suggest
> > > > > >> > > > > > > > > to
> > > > > >> > > > > > > > > > > > start
> > > > > >> > > > > > > > > > > > >> >> with
> > > > > >> > > > > > > > > > > > >> >> >>> the
> > > > > >> > > > > > > > > > > > >> >> >>> > use case.
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> > Yufei
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> > On Fri, Feb 27, 2026 at
> 3:42 PM
> > > > Dmitri
> > > > > >> > > > > > Bourlatchkov <
> > > > > >> > > > > > > > > > > > >> >> [email protected]>
> > > > > >> > > > > > > > > > > > >> >> >>> > wrote:
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> > > Hi Anand,
> > > > > >> > > > > > > > > > > > >> >> >>> > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > Sharing my view... subject
> to
> > > > > >> discussion:
> > > > > >> > > > > > > > > > > > >> >> >>> > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > 1. Adding non-IRC REST API
> to
> > > > > Polaris
> > > > > >> is
> > > > > >> > > > > > perfectly
> > > > > >> > > > > > > > > fine.
> > > > > >> > > > > > > > > > > > >> >> >>> > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > Figuring out specific
> endpoint
> > > > URIs
> > > > > >> and
> > > > > >> > > > > payloads
> > > > > >> > > > > > > > might
> > > > > >> > > > > > > > > > > > require
> > > > > >> > > > > > > > > > > > >> a
> > > > > >> > > > > > > > > > > > >> >> few
> > > > > >> > > > > > > > > > > > >> >> >>> > > roundtrips, so opening a
> > separate
> > > > > >> thread
> > > > > >> > > for
> > > > > >> > > > > that
> > > > > >> > > > > > > > might
> > > > > >> > > > > > > > > > be
> > > > > >> > > > > > > > > > > > >> best.
> > > > > >> > > > > > > > > > > > >> >> >>> > > Contributors commonly create
> > > > Google
> > > > > >> Docs
> > > > > >> > > for
> > > > > >> > > > > new
> > > > > >> > > > > > > API
> > > > > >> > > > > > > > > > > > proposals
> > > > > >> > > > > > > > > > > > >> too
> > > > > >> > > > > > > > > > > > >> >> >>> (they
> > > > > >> > > > > > > > > > > > >> >> >>> > > fairly easy to update as the
> > email
> > > > > >> > > discussion
> > > > > >> > > > > > > > > > progresses).
> > > > > >> > > > > > > > > > > > >> >> >>> > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > There was a suggestion to
> try
> > > > > Markdown
> > > > > >> > > (with
> > > > > >> > > > > PRs)
> > > > > >> > > > > > > for
> > > > > >> > > > > > > > > > > > proposals
> > > > > >> > > > > > > > > > > > >> >> [1]
> > > > > >> > > > > > > > > > > > >> >> >>> ...
> > > > > >> > > > > > > > > > > > >> >> >>> > > feel free to give it a try
> if
> > you
> > > > > are
> > > > > >> > > > > comfortable
> > > > > >> > > > > > > > with
> > > > > >> > > > > > > > > > > that.
> > > > > >> > > > > > > > > > > > >> >> >>> > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > 2. Could you clarify whether
> > you
> > > > > mean
> > > > > >> end
> > > > > >> > > > user
> > > > > >> > > > > > > > > utilities
> > > > > >> > > > > > > > > > or
> > > > > >> > > > > > > > > > > > >> admin
> > > > > >> > > > > > > > > > > > >> >> >>> user
> > > > > >> > > > > > > > > > > > >> >> >>> > > utilities? In the latter
> case
> > > > those
> > > > > >> might
> > > > > >> > > be
> > > > > >> > > > > more
> > > > > >> > > > > > > > > > suitable
> > > > > >> > > > > > > > > > > > for
> > > > > >> > > > > > > > > > > > >> the
> > > > > >> > > > > > > > > > > > >> >> >>> Admin
> > > > > >> > > > > > > > > > > > >> >> >>> > > CLI (java) not the Python
> CLI,
> > > > IMHO.
> > > > > >> > > > > > > > > > > > >> >> >>> > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > Why would these utilities be
> > > > common
> > > > > >> with
> > > > > >> > > > > events?
> > > > > >> > > > > > > > IMHO,
> > > > > >> > > > > > > > > > > event
> > > > > >> > > > > > > > > > > > >> use
> > > > > >> > > > > > > > > > > > >> >> >>> cases
> > > > > >> > > > > > > > > > > > >> >> >>> > are
> > > > > >> > > > > > > > > > > > >> >> >>> > > distinct from scan/commit
> > metrics.
> > > > > >> > > > > > > > > > > > >> >> >>> > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > 3. I'd prefer separating
> > metrics
> > > > > >> > > persistence
> > > > > >> > > > > from
> > > > > >> > > > > > > > > > MetaStore
> > > > > >> > > > > > > > > > > > >> >> >>> persistence
> > > > > >> > > > > > > > > > > > >> >> >>> > at
> > > > > >> > > > > > > > > > > > >> >> >>> > > the code level, so that they
> > could
> > > > > be
> > > > > >> > mixed
> > > > > >> > > > and
> > > > > >> > > > > > > > matched
> > > > > >> > > > > > > > > > > > >> >> >>> independently.
> > > > > >> > > > > > > > > > > > >> >> >>> > The
> > > > > >> > > > > > > > > > > > >> >> >>> > > separate datasource question
> > will
> > > > > >> become
> > > > > >> > a
> > > > > >> > > > > > > non-issue
> > > > > >> > > > > > > > > with
> > > > > >> > > > > > > > > > > > that
> > > > > >> > > > > > > > > > > > >> >> >>> approach,
> > > > > >> > > > > > > > > > > > >> >> >>> > I
> > > > > >> > > > > > > > > > > > >> >> >>> > > guess.
> > > > > >> > > > > > > > > > > > >> >> >>> > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > The rationale for separating
> > scan
> > > > > >> metrics
> > > > > >> > > and
> > > > > >> > > > > > > > metastore
> > > > > >> > > > > > > > > > > > >> >> persistence
> > > > > >> > > > > > > > > > > > >> >> >>> is
> > > > > >> > > > > > > > > > > > >> >> >>> > that
> > > > > >> > > > > > > > > > > > >> >> >>> > > "cascading deletes" between
> > them
> > > > are
> > > > > >> > hardly
> > > > > >> > > > > ever
> > > > > >> > > > > > > > > > required.
> > > > > >> > > > > > > > > > > > >> >> >>> Furthermore,
> > > > > >> > > > > > > > > > > > >> >> >>> > the
> > > > > >> > > > > > > > > > > > >> >> >>> > > data and query patterns are
> > very
> > > > > >> > different
> > > > > >> > > so
> > > > > >> > > > > > > > different
> > > > > >> > > > > > > > > > > > >> >> technologies
> > > > > >> > > > > > > > > > > > >> >> >>> > might
> > > > > >> > > > > > > > > > > > >> >> >>> > > be beneficial in each case.
> > > > > >> > > > > > > > > > > > >> >> >>> > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > [1]
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>>
> > > > > >> > > > > > > > > > > > >> >>
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > >
> > > > > >> > > > > > > > > > >
> > > > > >> > > > > > > > > >
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > >
> > > > > >> > > > > > >
> > > > > >> > > > > >
> > > > > >> > > > >
> > > > > >> > > >
> > > > > >> > >
> > > > > >> >
> > > > > >>
> > > > >
> > > >
> >
> https://urldefense.com/v3/__https://lists.apache.org/thread/yto2wp982t43h1mqjwnslswhws5z47cy__;!!Iz9xO38YGHZK!5EuyFFkk3vhRWVIRvQAWBSQfpJkTMA9HxugzDwXmN0LPPqhEFxYkFRGVhtb8AqUwXtDh2OplcMnbMDHKxYDakNU$
> >> > > >> > > > > > > > > > > > >> >> >>> > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > Cheers,
> > > > > >> > > > > > > > > > > > >> >> >>> > > Dmitri.
> > > > > >> > > > > > > > > > > > >> >> >>> > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > On Fri, Feb 27, 2026 at
> > 6:19 PM
> > > > > Anand
> > > > > >> > Kumar
> > > > > >> > > > > > > Sankaran
> > > > > >> > > > > > > > > via
> > > > > >> > > > > > > > > > > dev
> > > > > >> > > > > > > > > > > > <
> > > > > >> > > > > > > > > > > > >> >> >>> > > [email protected]>
> > wrote:
> > > > > >> > > > > > > > > > > > >> >> >>> > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > > Thanks all. This PR is
> > merged
> > > > now.
> > > > > >> > > > > > > > > > > > >> >> >>> > > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > > Here are the follow-up
> > features
> > > > /
> > > > > >> work
> > > > > >> > > > > needed.
> > > > > >> > > > > > > > These
> > > > > >> > > > > > > > > > > were
> > > > > >> > > > > > > > > > > > >> all
> > > > > >> > > > > > > > > > > > >> >> >>> part of
> > > > > >> > > > > > > > > > > > >> >> >>> > > the
> > > > > >> > > > > > > > > > > > >> >> >>> > > > merged PR at some point in
> > time
> > > > > and
> > > > > >> > were
> > > > > >> > > > > > removed
> > > > > >> > > > > > > to
> > > > > >> > > > > > > > > > > reduce
> > > > > >> > > > > > > > > > > > >> >> scope.
> > > > > >> > > > > > > > > > > > >> >> >>> > > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > > Please let me know what
> you
> > > > think.
> > > > > >> > > > > > > > > > > > >> >> >>> > > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > >   1.  A REST API to
> paginate
> > > > > through
> > > > > >> > > table
> > > > > >> > > > > > > metrics.
> > > > > >> > > > > > > > > > This
> > > > > >> > > > > > > > > > > > >> will be
> > > > > >> > > > > > > > > > > > >> >> >>> > non-IRC
> > > > > >> > > > > > > > > > > > >> >> >>> > > > standard addition.
> > > > > >> > > > > > > > > > > > >> >> >>> > > >   2.  Utilities for
> > managing old
> > > > > >> > records,
> > > > > >> > > > > > should
> > > > > >> > > > > > > be
> > > > > >> > > > > > > > > > > common
> > > > > >> > > > > > > > > > > > >> with
> > > > > >> > > > > > > > > > > > >> >> >>> events.
> > > > > >> > > > > > > > > > > > >> >> >>> > > > There was some discussion
> > that
> > > > it
> > > > > >> > belongs
> > > > > >> > > > to
> > > > > >> > > > > > the
> > > > > >> > > > > > > > CLI.
> > > > > >> > > > > > > > > > > > >> >> >>> > > >   3.  Separate datasource
> > > > > (metrics,
> > > > > >> > > events,
> > > > > >> > > > > > even
> > > > > >> > > > > > > > > other
> > > > > >> > > > > > > > > > > > >> tables?).
> > > > > >> > > > > > > > > > > > >> >> >>> > > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > > Anything else?
> > > > > >> > > > > > > > > > > > >> >> >>> > > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > > -
> > > > > >> > > > > > > > > > > > >> >> >>> > > > Anand
> > > > > >> > > > > > > > > > > > >> >> >>> > > >
> > > > > >> > > > > > > > > > > > >> >> >>> > > >
> > > > > >> > > > > > > > > > > > >> >> >>> > >
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>> >
> > > > > >> > > > > > > > > > > > >> >> >>>
> > > > > >> > > > > > > > > > > > >> >> >>
> > > > > >> > > > > > > > > > > > >> >>
> > > > > >> > > > > > > > > > > > >> >
> > > > > >> > > > > > > > > > > > >>
> > > > > >> > > > > > > > > > > > >
> > > > > >> > > > > > > > > > > >
> > > > > >> > > > > > > > > > >
> > > > > >> > > > > > > > > >
> > > > > >> > > > > > > > >
> > > > > >> > > > > > > >
> > > > > >> > > > > > >
> > > > > >> > > > > >
> > > > > >> > > > >
> > > > > >> > > >
> > > > > >> > >
> > > > > >> >
> > > > > >>
> > > > > >
> > > > >
> > > >
> >
>
>

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