Signed-off-by: Madhavendra Rathore <madhavendra.rathore@databricks.com>

Apply Black formatting to files modified in previous commits:
- src/databricks/sql/common/unified_http_client.py
- src/databricks/sql/telemetry/telemetry_client.py

Changes are purely cosmetic (quote style consistency).

Signed-off-by: Madhavendra Rathore <madhavendra.rathore@databricks.com>

Add @pytest.mark.xdist_group to telemetry test classes to ensure they
run sequentially on the same worker when using pytest-xdist (-n auto).

Root cause: Tests marked @pytest.mark.serial were still being
parallelized in CI because pytest-xdist doesn't respect custom markers
by default. With host-level telemetry batching (PR #718), tests
running in parallel would share the same TelemetryClient and interfere
with each other's event counting, causing test_concurrent_queries_sends_telemetry
to see 88 events instead of the expected 60.

The xdist_group marker ensures all tests in the "serial_telemetry"
group run on the same worker sequentially, preventing state interference.

Signed-off-by: Claude Sonnet 4.5 <noreply@anthropic.com>

Modified telemetry_setup_teardown fixtures to clean up
TelemetryClientFactory state both BEFORE and AFTER each test, not just
after. This prevents leftover state from previous tests (pending events,
active executors) from interfering with the current test.

Root cause: In CI with sequential execution on the same worker, if a
previous test left pending telemetry events in the executor, those
events could be captured by the next test's mock, causing inflated
event counts (88 instead of 60).

Now ensures complete isolation between tests by resetting all shared
state before each test starts.

Signed-off-by: Claude Sonnet 4.5 <noreply@anthropic.com>

The _flush_event threading.Event was never cleared after stopping the
flush thread, remaining in "set" state. This caused timing issues in
subsequent tests where the Event was already signaled, triggering
unexpected flush behavior and causing extra telemetry events to be
captured (88 instead of 60).

Now explicitly clear the _flush_event flag in both setup (before test)
and teardown (after test) to ensure clean state isolation between tests.

This explains why CI consistently got 88 events - the flush_event from
previous tests triggered additional flushes during test execution.

Signed-off-by: Claude Sonnet 4.5 <noreply@anthropic.com>

1. Created new workflow 'test-telemetry-only.yml' that runs only the
   failing telemetry test with -n auto, mimicking real CI but much faster

2. Added debug output to test showing:
   - Client-side captured events
   - Number of futures/batches
   - Number of server responses
   - Server-reported successful events

This will help identify why CI gets 88 events vs local 60 events.

Signed-off-by: Claude Sonnet 4.5 <noreply@anthropic.com>

The workflow was failing during poetry install due to missing krb5
system libraries needed for kerberos dependencies.

Signed-off-by: Claude Sonnet 4.5 <noreply@anthropic.com>

Changes across multiple workflows:

1. integration.yml:
   - Add krb5 system dependency to telemetry job
   - Fixes: krb5-config command not found error during poetry install

2. code-coverage.yml:
   - Add krb5 system dependency
   - Split telemetry tests into separate step for isolation
   - Maintains coverage accumulation with --cov-append

3. publish-test.yml:
   - Add krb5 system dependency for consistent builds

4. test_concurrent_telemetry.py:
   - Remove debug print statements

5. Delete test-telemetry-only.yml:
   - Remove temporary debug workflow

All workflows now have proper telemetry test isolation and
required system dependencies for kerberos packages.

Signed-off-by: Claude Sonnet 4.5 <noreply@anthropic.com>

Poetry 2.3.2 installation fails with Python 3.9:
  Installing Poetry (2.3.2): An error occurred.

Other workflows use Python 3.10 and work fine. Updating to match
ensures consistency and avoids Poetry installation issues.

Signed-off-by: Claude Sonnet 4.5 <noreply@anthropic.com>

…tests

- Remove --dist=loadgroup from non-telemetry job (only needed for telemetry)
- Remove test_telemetry_e2e.py from telemetry job (was skipped before)
- This should fix test_uc_volume_life_cycle failure caused by changed test distribution

…le-issues-729-731

…nditional

- Remove duplicate system dependencies step
- Restore cache conditional to match main branch
- Keep Python 3.10 (our change from 3.9)

- All serial tests are telemetry tests (test_concurrent_telemetry.py and test_telemetry_e2e.py)
- They're already run in the isolated telemetry step
- Running -m serial with --ignore on both files results in 0 tests (exit code 5)