feat(csharp): implement FeatureFlagCache (WI-3.1) by jadewang-db · Pull Request #165 · adbc-drivers/databricks

jadewang-db · 2026-01-22T18:42:12Z

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stack/wi-3.1-feature-flag-cache [Files changed]
- stack/wi-3.4-databricks-telemetry-exporter [Files changed]
  - stack/wi-3.5-metrics-aggregator [Files changed]
    - stack/wi-3.5-circuit-breaker-manager [Files changed]
      - stack/e2e-feature-flag-cache-tests [Files changed]
        
        stack/databricks-activity-listener [Files changed]
        
        stack/circuit-breaker-telemetry-exporter [Files changed]
        
        stack/telemetry-client-manager-wi-3.2 [Files changed]
        
        stack/telemetry-client-wi-5.5 [Files changed]
        
        stack/telemetry-client-manager-e2e-wi-7 [Files changed]
        stack/telemetry-client-e2e-tests-wi-7-standalone [Files changed]
        stack/wi-6.1-databricks-connection-telemetry-integration [Files changed]
        stack/wi-6.2-telemetry-tags-driver-activities [Files changed]
        stack/wi-9-full-integration-e2e-tests [Files changed]

csharp/src/FeatureFlagCache.cs

…(WI-3.1) Refactored FeatureFlagCache based on updated design doc requirements: - Moved from Telemetry namespace to root namespace (AdbcDrivers.Databricks) to make it a generic, reusable component - Added HTTP API integration to fetch flags from /api/2.0/connector-service/feature-flags/OSS_JDBC/{version} - Implemented background refresh scheduler with server-provided TTL - Added FeatureFlagsResponse model for API response parsing - Updated FeatureFlagContext interface: - GetFlagValue(string) - get individual flag value - GetAllFlags() - get all cached flags as dictionary - IsFeatureEnabled(string) - check if flag is "true" - Shutdown() - stop background refresh scheduler - IDisposable for proper cleanup - Updated FeatureFlagCache.GetOrCreateContext() to accept HttpClient and driver version parameters - Updated all unit tests for new interface Co-Authored-By: Claude <noreply@anthropic.com>

…I-3.1) Integrated feature flag cache into the connection lifecycle: - Fetch feature flags from server during connection initialization - Merge flags into Properties dictionary with proper priority: User Properties > Feature Flags > Driver Defaults - Track host for proper context cleanup on Dispose - Release feature flag context when connection is disposed - All feature flag operations are fail-safe (errors logged, not thrown) The feature flag endpoint used is: GET /api/2.0/connector-service/feature-flags/OSS_JDBC/{driver_version} Co-Authored-By: Claude <noreply@anthropic.com>

…-3.1) - Add EnsureSuccessStatusCode pattern for HTTP response handling - Extract common HTTP fetch code into single FetchFeatureFlags method - Make feature flag endpoint configurable via optional parameter - Replace Debug.WriteLine with Activity trace pattern - Add E2E tests for FeatureFlagCache using real Databricks instance Co-Authored-By: Claude (databricks-claude-opus-4-5) <noreply@anthropic.com>

…WI-3.1) - Move MergePropertiesWithFeatureFlags, TryGetHost, CreateFeatureFlagHttpClient, and MergeProperties helper methods from DatabricksConnection to FeatureFlagCache - Replace Debug.WriteLine with ActivitySource tracing for structured events - DatabricksConnection now delegates to FeatureFlagCache.GetInstance().MergePropertiesWithFeatureFlags() Co-Authored-By: Claude (databricks-claude-opus-4-5) <noreply@anthropic.com>

…ructor (WI-3.1) Replace hardcoded "1.0.0" with ApacheUtility.GetAssemblyVersion() to use the actual driver version in the test constructor. Co-Authored-By: Claude (databricks-claude-opus-4-5) <noreply@anthropic.com>

…-3.1) - Add proxy support using HiveServer2ProxyConfigurator - Handle protocol prefix in host (e.g., "https://myhost.databricks.com") - Add configurable timeout via FeatureFlagTimeoutSeconds parameter - Use consistent User-Agent format: DatabricksJDBCDriverOSS/{version} (ADBC) - Rename variables to localProperties/remoteProperties for clarity - Remove IsFeatureEnabled method from FeatureFlagContext - Use EnsureSuccessOrThrow extension method for HTTP error handling - Enhance E2E tests to verify flags fetched and cache cleanup Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Add support for OAuth client_credentials (M2M) authentication in addition to token-based (PAT) auth for feature flag API calls. This ensures feature flags work with all supported authentication methods. - Add AuthHelper class with shared token extraction methods - Update FeatureFlagCache to use AuthHelper.GetAccessToken - Update HttpHandlerFactory to use AuthHelper.GetTokenFromProperties Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Move the test factory method from production to test code: - Make FeatureFlagContext constructor internal instead of private - Make Ttl setter internal to allow tests to configure TTL - Remove CreateForTesting from FeatureFlagContext.cs - Add CreateTestContext helper method in FeatureFlagCacheTests.cs This addresses the PR review feedback that test-only code should not be in production source files. Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

…(WI-3.1) - Remove unused GetAccessToken and GetOAuthClientCredentialsToken from AuthHelper - Extract User-Agent logic to shared UserAgentHelper class (used by HttpClientFactory) - Remove enableTokenRefresh parameter from AddAuthHandlers (always enabled) - Remove unused CreateOAuthHttpClient from HttpClientFactory Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Re-add the DriverConfigTakePrecedence parameter and precedence control logic that was removed in commit 9d2c670. This allows users to control whether environment config (DATABRICKS_CONFIG_FILE) takes precedence over passed-in properties during configuration merging. - Add DriverConfigTakePrecedence constant to DatabricksParameters - Add DetermineDriverConfigPrecedence method to DatabricksDatabase - Update MergeWithDefaultEnvironmentConfig to respect precedence flag Default behavior (false): passed-in properties override environment config When true: environment config properties override passed-in properties Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

The auth HTTP client is now managed internally by HttpHandlerFactory rather than stored as an instance field in StatementExecutionConnection. Updated tests to verify behavior rather than internal implementation details. Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

github-actions · 2026-02-10T03:54:03Z

🚀 Integration tests triggered! View workflow run

samikshya-db

LGTM!

jadewang-db had a problem deploying to azure-prod January 22, 2026 18:42 — with GitHub Actions Error

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jadewang-db marked this pull request as ready for review January 22, 2026 22:29

jadewang-db commented Jan 23, 2026

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csharp/src/FeatureFlagCache.cs Show resolved Hide resolved

jadewang-db force-pushed the stack/wi-3.1-feature-flag-cache branch from 9681fe2 to 1d6e3d5 Compare January 23, 2026 21:14

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jadewang-db force-pushed the stack/wi-3.1-feature-flag-cache branch from 1d6e3d5 to 8c30fc0 Compare January 23, 2026 21:43

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jadewang-db force-pushed the stack/wi-3.1-feature-flag-cache branch from 8c30fc0 to b1a8b39 Compare January 26, 2026 22:43

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jadewang-db force-pushed the stack/wi-3.1-feature-flag-cache branch from b1a8b39 to 9204712 Compare January 26, 2026 23:01

Jade Wang and others added 19 commits February 10, 2026 01:26

Address comments and refactoring

4cc776a

fix e2e test and add more ttl based unit test

86c575e

make SEA working with feature flag cache

2a1e09c

refactor auth

ecc2cb1

remove unnecessary changes

9e82256

remove duplicate timeout configuration code

a79bc42

address comments

48e9a1a

fix(csharp): fix CRLF line endings in DatabricksParameters.cs

fe6b8cc

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

jadewang-db force-pushed the stack/wi-3.1-feature-flag-cache branch from adfe2b9 to 2262e9d Compare February 10, 2026 01:30

jadewang-db had a problem deploying to azure-prod February 10, 2026 01:30 — with GitHub Actions Failure

fix test failures

78733f3

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jadewang-db added the integration-test Trigger integration tests in internal repo label Feb 10, 2026

samikshya-db approved these changes Feb 10, 2026

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jadewang-db added this pull request to the merge queue Feb 10, 2026

Merged via the queue into main with commit 590c103 Feb 10, 2026
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jadewang-db deleted the stack/wi-3.1-feature-flag-cache branch February 10, 2026 04:45

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feat(csharp): implement FeatureFlagCache (WI-3.1)#165

feat(csharp): implement FeatureFlagCache (WI-3.1)#165
jadewang-db merged 21 commits intomainfrom
stack/wi-3.1-feature-flag-cache

jadewang-db commented Jan 22, 2026 •

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jadewang-db commented Jan 22, 2026 •

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