[FLINK-39619][docs] Add release notes for Flink 2.3 by lihaosky · Pull Request #28123 · apache/flink

lihaosky · 2026-05-07T07:17:41Z

What is the purpose of the change

Adds the release notes for the upcoming Flink 2.3 release, modeled on the format of the
2.2 release notes.
Contents are derived from the FLIP wiki pages for the FLIPs included in 2.3 (FLIP-339, FLIP-487,
FLIP-495, FLIP-547, FLIP-549, FLIP-550, FLIP-553, FLIP-555, FLIP-557, FLIP-558, FLIP-559,
FLIP-560, FLIP-561, FLIP-564, FLIP-565), with motivation/impact details pulled from each FLIP's
umbrella JIRA where present.

JIRA: FLINK-39619

Brief change log

Section coverage in docs/content/release-notes/flink-2.3.md:

Table SQL / API: FROM_CHANGELOG/TO_CHANGELOG PTFs (FLIP-564), CREATE/ALTER MATERIALIZED TABLE parity (FLIP-550), START_MODE for materialized table evolution (FLIP-557), ARTIFACT keyword (FLIP-559), SinkUpsertMaterializer / ON CONFLICT (FLIP-558), Process Table Function enhancements (FLIP-565).
Connectors: Native S3 FileSystem (FLIP-555).
Runtime: Adaptive Partition Selection (FLIP-339), AdaptiveScheduler rescale history (FLIP-495) + Web UI (FLIP-487), checkpointing during recovery (FLIP-547), Application Management (FLIP-549), Application Capability Enhancement (FLIP-560), robust OTel gRPC exporter (FLIP-553).
Documentation: docs restructure (FLIP-561).

Verifying this change

This change is a docs-only addition; no code paths are exercised.

Does this pull request potentially affect one of the following parts:

Dependencies (does it add or upgrade a dependency): no
The public API, i.e., is any changed class annotated with @Public(Evolving): no
The serializers: no
The runtime per-record code paths (performance sensitive): no
Anything that affects deployment or recovery: no
The S3 file system connector: no

Documentation

Does this pull request introduce a new feature? no
If yes, how is the feature documented? docs (release notes only)

…lla tickets

flinkbot · 2026-05-07T07:21:58Z

CI report:

2457fd4 Azure: SUCCESS Azure: FAILURE

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Izeren · 2026-05-07T13:55:33Z

+
+#### Robust OTel gRPC metric exporter
+
+##### [FLINK-38603](https://issues.apache.org/jira/browse/FLINK-38603) (FLIP-553)


Thank you for the update of release notes!

For this FLIP only 2/3 have been merged before the release cut off. Attribute name truncation is in master branch but won't be released in this round

twalthr

@lihaosky I would use the effective documentation added as part of the FLIP for the release notes. Not all FLIPs are fully completed. Also we should add the content of the Release Notes field in JIRA to this document.

twalthr · 2026-05-07T14:15:23Z

+The DataStream API has long offered `toChangelogStream()` and `fromChangelogStream()` for working
+with changelog streams; Flink 2.3 brings equivalent functionality to SQL via two new built-in
+Process Table Functions:

-A JDK update (affecting JDK 11.0.30+, 17.0.18+, 21.0.10+, and 24+) disabled `TLS_RSA_*` cipher suites.
-This was done to support forward-secrecy (RFC 9325) and comply with the IETF Draft on *Deprecating Obsolete Key Exchange Methods in TLS*.
+- `FROM_CHANGELOG` converts an append-only stream that carries an operation column (and optional
+  before/after row descriptors) into a dynamic table. A configurable `op_mapping` makes it
+  straightforward to plug in custom CDC formats (e.g. Debezium-style `c`/`u`/`d` codes), and
+  `invalid_op_handling` (`FAIL`/`LOG`/`SKIP`) controls how rows with unmapped operation codes
+  are treated.
+- `TO_CHANGELOG` is the inverse: it materializes a dynamic table back into an append-only
+  changelog stream. This is the first SQL-level operator that lets users convert
+  retract/upsert streams into append form, which is useful for archival, audit and writing to
+  append-only sinks. `produces_full_deletes` controls whether `-D` records carry the full row.

-To support these and future JDK versions, the default value for the Flink configuration option `security.ssl.algorithms` has been changed to a modern, widely available cipher suite:
+The two PTFs are designed to be symmetric, so `FROM_CHANGELOG(TO_CHANGELOG(table))` round-trips
+correctly. Both support `PARTITION BY` for parallel execution and `uid` for query evolution, and
+they expose a `state_ttl` parameter for state retention.


The FLIP is not fully implemented yet, only some signatures made it to the release. @gustavodemorais could you write short summary what works in 2.3?

Hey @twalthr — confirmed against release-2.3.

FROM_CHANGELOG (FLINK-39261)

Append-only stream with an op column → updating dynamic table.

Default op codes (INSERT, UPDATE_BEFORE, UPDATE_AFTER, DELETE).

Custom op column name via op => DESCRIPTOR(my_op).

Custom op_mapping with comma-separated keys.

Unmapped or NULL op codes fail with TableRuntimeException. No error_handling argument (the master-only follow-up that adds FAIL/SKIP was not cherry-picked).

Java Table#fromChangelog(...) and PyFlink Table.from_changelog(...) (FLINK-39479).

Row semantics only — PARTITION BY is rejected (FLINK-39537 is open).

Retract output only — UPDATE_AFTER without UPDATE_BEFORE (upsert) is rejected.

TO_CHANGELOG (FLINK-39259, FLINK-39349, FLINK-39419)

Dynamic table → append-only stream with an op column.

Custom op column name and op_mapping; deletion-flag pattern via comma-separated keys.

Filtering: only mapped operations forwarded.

Row semantics, full deletes, requires UPDATE_BEFORE upstream.

Java Table#toChangelog(...) and PyFlink Table.to_changelog(...) (FLINK-39442).

No PARTITION BY — TO_CHANGELOG set semantics (FLINK-39614) landed on master after the 2.3 cut.

Retract input only.

Not in 2.3

state_ttl argument — not supported yet, not declared on either PTF in any branch.

FROM_CHANGELOG error_handling (FLINK-39495 + follow-up, master only). The can be back-ported to 2.3

FROM_CHANGELOG PARTITION BY (FLINK-39537, open). We are done with the work and we need to merge to master and backport to 2.3

TO_CHANGELOG PARTITION BY (FLINK-39614, master). Merged to master and needs to be backported to 2.3

Conditional traits for PTFs (FLINK-39392, master). needs to be backported to 2.3.

Upsert input/output for either PTF.

Release-notes adjustments to consider

Drop the state_ttl mention — not declared on either PTF.

Drop invalid_op_handling / LOG — the parameter doesn't exist; even on master only error_handling (FAIL/SKIP) exists, and it's not in 2.3.

Drop produces_full_deletes — TO_CHANGELOG in 2.3 is locked to full deletes; no such argument is exposed.

Soften "Both support PARTITION BY" — neither does in 2.3 yet, unless we backport it and we will let you know.

The "round-trips correctly" claim holds only for the row-semantics retract case.

I will discuss with @gustavodemorais on the remaining PRs that are on master and if we backport them to 2.3. We will let you know to update the release notes! Many thanks!

twalthr · 2026-05-07T14:16:07Z

+- **`ValueView`**: a new lazy single-value state primitive (`value()`, `update()`, `isEmpty()`,
+  `clear()`) joins the existing `MapView` and `ListView` for working with single-element state
+  efficiently.
+- **Broadcast state**: PTFs support broadcast state through the new
+  `@ArgumentHint(ArgumentTrait.BROADCAST_SEMANTIC_TABLE)` and `@StateHint(StateKind.BROADCAST)`
+  annotations, plus `@ArgumentHint(ArgumentTrait.NOTIFY_STATEFUL_SETS)` for re-evaluating keys
+  when broadcast state changes.


This has not made it to 2.3 yet.

alpinegizmo · 2026-05-07T15:57:30Z

We should include https://issues.apache.org/jira/browse/FLINK-37399 and https://issues.apache.org/jira/browse/FLINK-35661. These are critical issues it would be good to highlight.

lihaosky added 3 commits May 6, 2026 15:05

[FLINK-39619][docs] Add release notes for Flink 2.3

11ee3f3

[FLINK-39619][docs] Restrict release notes to FLIP-derived content

8bdd7cb

[FLINK-39619][docs] Enrich release notes with details from FLIP umbre…

2457fd4

…lla tickets

lihaosky mentioned this pull request May 7, 2026

[FLINK-39619][docs] Add release notes for Flink 2.3 #28122

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[FLINK-39619][docs] Add release notes for Flink 2.3#28123

[FLINK-39619][docs] Add release notes for Flink 2.3#28123
lihaosky wants to merge 3 commits intoapache:masterfrom
confluentinc:flink-2.3-release-note

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		#### Robust OTel gRPC metric exporter

		##### [FLINK-38603](https://issues.apache.org/jira/browse/FLINK-38603) (FLIP-553)

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lihaosky commented May 7, 2026

What is the purpose of the change

Brief change log

Verifying this change

Does this pull request potentially affect one of the following parts:

Documentation

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FROM_CHANGELOG (FLINK-39261)

TO_CHANGELOG (FLINK-39259, FLINK-39349, FLINK-39419)

Not in 2.3

Release-notes adjustments to consider

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flinkbot commented May 7, 2026 •

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`FROM_CHANGELOG` (FLINK-39261)

`TO_CHANGELOG` (FLINK-39259, FLINK-39349, FLINK-39419)

raminqaf May 8, 2026 •

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