* fix: configure keepAlive time for gRPC TCP connections

* fix tests

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* fix tests

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* fix flaky abort retry error

* 🦉 Updates from OwlBot post-processor

See https://github.com/googleapis/repo-automation-bots/blob/main/packages/owl-bot/README.md

* update owlbot to persist the changes

* fix owlbot

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Source-Link: googleapis/synthtool@6702a34
Post-Processor: gcr.io/cloud-devrel-public-resources/owlbot-python:latest@sha256:fbbc8db67afd8b7d71bf694c5081a32da0c528eba166fbcffb3b6e56ddf907d5

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

* feat: add support for experimental host

* fix lint issues

* fixed unit tests

* added docmentation for new client option

---------

Co-authored-by: rahul2393 <[email protected]>

…ult (#1410)

This change enables OpenTelemetry metrics and tracing by default. [Fix
for [Issues
1222](#1222)]

- [ ] Regenerate this pull request now.

BEGIN_COMMIT_OVERRIDE
feat: Exposing AutoscalingConfig in InstancePartition
fix: Deprecate credentials_file argument
END_COMMIT_OVERRIDE

PiperOrigin-RevId: 825184314

Source-Link:
googleapis/googleapis@72e7439

Source-Link:
googleapis/googleapis-gen@007caa0
Copy-Tag:
eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiMDA3Y2FhMDZiYWM2NzY1NzdmOGQ4NDViODc5M2MxNmVmZjY2YWM5YSJ9

BEGIN_NESTED_COMMIT
fix: Deprecate credentials_file argument
chore: Update gapic-generator-python to 1.28.0

PiperOrigin-RevId: 816753840

Source-Link:
googleapis/googleapis@d06cf27

Source-Link:
googleapis/googleapis-gen@a524e73
Copy-Tag:
eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiYTUyNGU3MzEwODgyYmJiOTliZmUxMzk5YjE4YmVkMzI4OTc5MjExYyJ9
END_NESTED_COMMIT

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>
Co-authored-by: Anthonios Partheniou <[email protected]>

…butes (#1449)

This change enhances observability by introducing these new features:

1. **Cloud Region Attribute**: The `cloud.region` attribute is now added
to all OpenTelemetry spans generated by the Spanner client. This
provides better geographical context for traces, aiding in performance
analysis and debugging across different regions.

2. **Transaction Tag**: The `transaction_tag` set on a `Transaction`
object is now correctly propagated and included in the `Commit` request.
This allows for better end-to-end traceability of transactions.

3. **Request Tag**: This introduces support for `request_tag` on
individual Spanner operations like `read`, `execute_sql`, and
`execute_update`. When a `request_tag` is provided in the
`request_options`, it is now added as a `spanner.request_tag` attribute
to the corresponding OpenTelemetry span. This allows for more granular
tracing and debugging of specific requests within a transaction or a
snapshot.

---------

Co-authored-by: surbhigarg92 <[email protected]>

- [ ] Regenerate this pull request now.

PiperOrigin-RevId: 833474957

Source-Link:
googleapis/googleapis@7418c8b

Source-Link:
googleapis/googleapis-gen@f969a4a
Copy-Tag:
eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiZjk2OWE0YTVhZDk5N2JhZjE4OWMzOTkzMTYyOTdkNjBhODE5ODg1YiJ9

BEGIN_NESTED_COMMIT
feat: Add Send and Ack mutations for Queues
feat: Add QueryAdvisorResult for query plan
docs: Update description for the BatchCreateSessionsRequest and Session
docs: Update description for the IsolationLevel

PiperOrigin-RevId: 832425466

Source-Link:
googleapis/googleapis@0eeb1be

Source-Link:
googleapis/googleapis-gen@bae4179
Copy-Tag:
eyJwIjoiLmdpdGh1Yi8uT3dsQm90LnlhbWwiLCJoIjoiYmFlNDE3OTI1MjAzZTY4YzgwNmQ5ZjZiZmUzYzIwYWIzY2JmNWQ4NiJ9
END_NESTED_COMMIT

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>

Towards googleapis/librarian#2460

Make built-in metrics enabled by default

This change inverts the logic for enabling built-in OpenTelemetry
metrics. Previously, metrics were disabled by default and could be
enabled by setting `ENABLE_SPANNER_METRICS_ENV_VAR=true`.

With this update, metrics are now enabled by default to provide better
out-of-the-box observability for users.

To disable metrics, users must now set the new environment variable:
`SPANNER_DISABLE_BUILTIN_METRICS=true`

The old `ENABLE_SPANNER_METRICS_ENV_VAR` is no longer used. Unit tests
have been updated to reflect this new opt-out behavior.

**BREAKING CHANGE**: Built-in metrics are now enabled by default. Users
who previously did not set any environment variables will have metrics
collection and export turned on automatically after upgrading. To
restore the previous behavior and disable metrics, thry have to set the
`SPANNER_DISABLE_BUILTIN_METRICS` environment variable to `true`.

This PR adds support for Python 3.14 to the library.

Key changes include:

Key changes include:
   - Updates to `owlbot.py` to include Python 3.14.
- Adding Python 3.14 to the test matrix in
`.github/workflows/presubmit.yaml`.
   - Verified `setup.py` includes the Python 3.14 classifier.
   - Verified `CONTRIBUTING.rst` includes Python 3.14.
   - Verified `noxfile.py` updates for 3.14.
- Updated Kokoro configurations in `.kokoro/presubmit/` to use
`system-3.14` session.
   - Updated `librarian.py` to account for post-processing.
- Fixed a concurrency issue in `tests/unit/test_spanner.py` to make the
test suite pass on Python 3.14.

Towards internal issue: b/375664027

---------

Co-authored-by: Owl Bot <gcf-owl-bot[bot]@users.noreply.github.com>
Co-authored-by: gcf-owl-bot[bot] <78513119+gcf-owl-bot[bot]@users.noreply.github.com>
Co-authored-by: Subham Sinha <[email protected]>
Co-authored-by: surbhigarg92 <[email protected]>

PR created by the Librarian CLI to initialize a release. Merging this PR will auto trigger a release.

Librarian Version: v1.0.0
Language Image: us-central1-docker.pkg.dev/cloud-sdk-librarian-prod/images-prod/python-librarian-generator@sha256:8e2c32496077054105bd06c54a59d6a6694287bc053588e24debe6da6920ad91
<details><summary>google-cloud-spanner: 3.60.0</summary>

## [3.60.0](https://togithub.com/googleapis/python-spanner/compare/v3.59.0...v3.60.0) (2025-12-10)

### Features

* make built-in metrics enabled by default (#1459) ([64aebe7](https://togithub.com/googleapis/python-spanner/commit/64aebe7e))

* Exposing AutoscalingConfig in InstancePartition ([8b6f154](https://togithub.com/googleapis/python-spanner/commit/8b6f1540))

* add support for experimental host (#1452) ([9535e5e](https://togithub.com/googleapis/python-spanner/commit/9535e5e0))

* enable OpenTelemetry metrics and tracing by default (#1410) ([bb5095d](https://togithub.com/googleapis/python-spanner/commit/bb5095df))

* add cloud.region, request_tag and transaction_tag in span attributes (#1449) ([d37fb80](https://togithub.com/googleapis/python-spanner/commit/d37fb80a))

* Add QueryAdvisorResult for query plan (PiperOrigin-RevId: 832425466) ([e08260f](https://togithub.com/googleapis/python-spanner/commit/e08260fe))

* Add Send and Ack mutations for Queues (PiperOrigin-RevId: 832425466) ([e08260f](https://togithub.com/googleapis/python-spanner/commit/e08260fe))

* Add Spanner location API (#1457) (PiperOrigin-RevId: 833474957) ([e08260f](https://togithub.com/googleapis/python-spanner/commit/e08260fe))

### Bug Fixes

* Deprecate credentials_file argument ([8b6f154](https://togithub.com/googleapis/python-spanner/commit/8b6f1540))

* configure keepAlive time for gRPC TCP connections (#1448) ([efb2833](https://togithub.com/googleapis/python-spanner/commit/efb2833e))

* Provide Spanner Option to disable metrics (#1460) ([f1ebc43](https://togithub.com/googleapis/python-spanner/commit/f1ebc43b))

### Documentation

* Update description for the BatchCreateSessionsRequest and Session (PiperOrigin-RevId: 832425466) ([e08260f](https://togithub.com/googleapis/python-spanner/commit/e08260fe))

* Update description for the IsolationLevel (PiperOrigin-RevId: 832425466) ([e08260f](https://togithub.com/googleapis/python-spanner/commit/e08260fe))

</details>