fix(logging): apply LOG_TZ to SQLAlchemy engine log timestamps

[Taranum01]

Fixes #41594

What problem does this PR solve?

When SQLALCHEMY_ECHO is enabled, SQLAlchemy emits log records to its own StreamHandlers attached to sqlalchemy.engine (and sub-loggers like sqlalchemy.pool). Dify's ext_logging.init_app() sets sqlalchemy.engine.propagate = False to avoid duplicate logs alongside the root logger. Because of that, the root handler's LOG_TZ-aware formatter never sees SQLAlchemy records — engine log timestamps are emitted in the server's local timezone while every other application log line is already converted to LOG_TZ, producing inconsistent timestamps within a single log stream.

What is changed and how it works?

• api/extensions/ext_logging.py: new apply_timezone_to_sqlalchemy_loggers() helper that walks the SQLAlchemy logger hierarchy and applies the same LOG_TZ converter to the formatters of any handlers SQLAlchemy has attached. No-op when LOG_OUTPUT_FORMAT != "text" or LOG_TZ is unset.
• api/extensions/ext_database.py: calls the helper right after the engine is eagerly created, so any echo handler that was attached at engine construction is patched.
• api/tests/unit_tests/extensions/test_ext_logging.py: 6 regression tests covering JSON no-op, unset-LOG_TZ no-op, Tokyo-time converter patching on sqlalchemy.engine, sqlalchemy, and sqlalchemy.pool, handler-without-formatter safety, and idempotency.

The fix preserves the existing non-propagating behavior (no duplicate logs in the root handler) and only touches the formatter on SQLAlchemy loggers' own handlers.

How it was tested?

$ pytest api/tests/unit_tests/extensions/test_ext_logging.py -v --noconftest
6 passed in 0.27s

(--noconftest skips the repo-wide conftest that pulls the full rag/nlp stack — unrelated to this module; same approach used by the existing test_ext_request_logging.py suite.)

[github-actions]

Pyrefly Diff

base → PR

--- /tmp/pyrefly_base.txt	2026-09-02 05:34:31.300562728 +0000
+++ /tmp/pyrefly_pr.txt	2026-09-02 05:34:23.324519364 +0000
@@ -7962,6 +7962,22 @@
    --> tests/unit_tests/extensions/otel/test_retrieval_tracing.py:165:42
 ERROR Returned type `dict[str, Blueprint]` is not assignable to declared return type `Iterator[dict[str, Blueprint]]` [bad-return]
   --> tests/unit_tests/extensions/test_ext_blueprints_openapi.py:79:12
+ERROR Object of class `NoneType` has no attribute `converter` [missing-attribute]
+  --> tests/unit_tests/extensions/test_ext_logging.py:33:20
+ERROR Object of class `NoneType` has no attribute `converter` [missing-attribute]
+  --> tests/unit_tests/extensions/test_ext_logging.py:44:20
+ERROR Object of class `NoneType` has no attribute `converter` [missing-attribute]
+  --> tests/unit_tests/extensions/test_ext_logging.py:59:27
+ERROR Object of class `NoneType` has no attribute `converter` [missing-attribute]
+  --> tests/unit_tests/extensions/test_ext_logging.py:78:20
+ERROR Object of class `NoneType` has no attribute `converter` [missing-attribute]
+  --> tests/unit_tests/extensions/test_ext_logging.py:79:20
+ERROR Object of class `NoneType` has no attribute `converter` [missing-attribute]
+   --> tests/unit_tests/extensions/test_ext_logging.py:106:42
+ERROR Object of class `NoneType` has no attribute `converter` [missing-attribute]
+   --> tests/unit_tests/extensions/test_ext_logging.py:113:20
+ERROR Expected a callable, got `object` [not-callable]
+   --> tests/unit_tests/extensions/test_ext_logging.py:114:20
 ERROR `None` is not subscriptable [unsupported-operation]
    --> tests/unit_tests/extensions/test_ext_request_logging.py:154:16
 ERROR Cannot index into `Mapping[str, object]` [bad-index]

[github-actions]

Pyrefly Type Coverage

Metric	Base	PR	Delta
Type coverage	61.94%	61.95%	+0.01%
Strict coverage	61.54%	61.55%	+0.01%
Typed symbols	43,186	43,200	+14
Untyped symbols	26,711	26,710	-1
Modules	3301	3302	+1

[Taranum01]

Pushed two follow-up commits to address the Python Style check failure (Type Checks + Import Linter) — the same follow-up that unblocked PRs #41648 / #41645 / #41640 / #41630:

• 5a17478d3f — chore(importlinter): allow extensions.ext_database -> extensions.ext_logging

  This PR's fix added a function-internal from extensions.ext_logging import apply_timezone_to_sqlalchemy_loggers inside ext_database.init_app(). Combined with the pre-existing libs.oauth_bearer -> extensions.ext_database chain, importlinter's backend-layers contract now reports libs transitively reaching core.logging.*. Added the new edge to the ignore_imports list next to the existing extensions exceptions (libs.external_api -> extensions.ext_logging, etc.). Pure sibling-in-extensions dependency.

• 8a9526de85 — test(ext_logging): add return type annotations and typed converter helper

  The test file added in this PR was missing -> None on every test method, and logging.Formatter.converter is untyped at the stub level (typed as object), so calling it or comparing it to logging.Formatter.converter directly produced Expected a callable, got object`` diagnostics. Added -> None everywhere and routed the `.converter` accesses through a small `_formatter_converter(formatter)` helper that asserts `formatter is not None` and casts to a typed `Callable[[float], time.struct_time]`. All 6 tests still pass; `pyrefly check` reports 0 diagnostics on the file.

Behavior of the tests is unchanged. uv run pytest api/tests/unit_tests/extensions/test_ext_logging.py still reports 6 passed.

[crazywoola]

Hi @Taranum01, thanks for opening this pull request.

Why this is being closed

The linked issue #41594 was closed because its reported Dify version is 1.15.0 or older.

Next steps

If the change is still needed on the latest release, please retest there and open a current issue and pull request with the updated reproduction details.