perf: Replace MessageToDict with optimized custom dict builder by abhijeet-dhumal · Pull Request #6015 · feast-dev/feast

abhijeet-dhumal · 2026-02-24T06:27:03Z

Summary

The feature server uses google.protobuf.json_format.MessageToDict for converting
GetOnlineFeaturesResponse to JSON, but this generic converter is slow due to
reflection-based field introspection.

Changes

Add feature_server_utils.py with convert_response_to_dict() function
Custom dict builder optimized for GetOnlineFeaturesResponse structure
Direct field access instead of reflection
Efficient type-specific value extraction
Serialize top-level status bool field (omitted when false, matching proto3 default behavior)
Add comprehensive unit tests for the new serialization

Performance Impact

~4x faster serialization, saving 5-15ms per request for typical feature responses
with 50-200 features.

Test Plan

Added unit tests in test_feature_server_utils.py
Tests verify output matches MessageToDict + proto_json.patch() format
Tests cover all Value types, timestamps, metadata, status codes, top-level status field
Performance test validates speedup
Passes make lint-python

franciscojavierarceo · 2026-03-06T05:07:14Z

+}
+
+
+def response_to_dict_fast(response: GetOnlineFeaturesResponse) -> Dict[str, Any]:


why not response_to_dict? better yet, convert_response_to_dict is a better description

Good call - renamed to convert_response_to_dict. The _fast suffix was leaking implementation details ✅

devin-ai-integration

Devin Review found 1 new potential issue.

View 9 additional findings in Devin Review.

franciscojavierarceo · 2026-03-25T12:55:57Z

@abhijeet-dhumal please resolve conflicts and update PR

Signed-off-by: abhijeet-dhumal <abhijeetdhumal652@gmail.com>

…nt FieldValues Signed-off-by: abhijeet-dhumal <abhijeetdhumal652@gmail.com>

… and precision, add base64 encoding for bytes Signed-off-by: abhijeet-dhumal <abhijeetdhumal652@gmail.com>

Signed-off-by: abhijeet-dhumal <abhijeetdhumal652@gmail.com>

devin-ai-integration

Devin Review found 3 potential issues.

View 5 additional findings in Devin Review.

devin-ai-integration · 2026-05-27T11:16:46Z

+    which = v.WhichOneof("val")
+    if which is None or which == "null_val":
+        return None
+    elif "_list_" in which:
+        return list(getattr(v, which).val)
+    else:
+        return getattr(v, which)


🔴 bytes_val values cause ORJSONResponse to raise TypeError

_value_to_native at feature_server_utils.py:68 returns raw bytes for bytes_val fields. Even if orjson were installed, orjson.dumps() cannot serialize Python bytes objects and raises TypeError: Type is not JSON serializable: bytes. The old code path returned the dict to FastAPI which processed it through jsonable_encoder (capable of handling bytes). The switch to ORJSONResponse bypasses that encoder, causing a regression for any response containing bytes-typed feature values.

Prompt for agents

In _value_to_native (feature_server_utils.py), when the value type is bytes_val, the raw bytes object is returned. orjson cannot serialize bytes. You need to either: (1) base64-encode bytes values before returning them (e.g. using base64.b64encode(val).decode('ascii')), or (2) not use ORJSONResponse and instead use a serializer that handles bytes. Note that bytes_list_val (handled by the _list_ branch) would also produce a list of bytes objects with the same issue.

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@abhijeet-dhumal bytes_val is still problem since you are using JSONResponse

Thanks for catching this, Nikhil! Now bytes_val and bytes_list_val now base64-encode the output before returning, so JSONResponse / json.dumps can serialize them without TypeError.

Please review!

abhijeet-dhumal · 2026-05-27T11:18:23Z

@ntkathole Apologies for the late reply here .. I have fixed and addressed the open reviews!

ntkathole · 2026-05-27T12:03:19Z

 from fastapi.concurrency import run_in_threadpool
 from fastapi.logger import logger
-from fastapi.responses import JSONResponse
+from fastapi.responses import JSONResponse, ORJSONResponse


ORJSONResponse has been deprecated in FastAPI.

https://fastapi.tiangolo.com/reference/responses/?h=ORJSON#fastapi.responses.ORJSONResponse

Signed-off-by: abhijeet-dhumal <abhijeetdhumal652@gmail.com>

Previous implementation used "_list_" substring check which silently returned protobuf objects (not JSON-serializable) for: - *_set_val types (bytes_set_val, string_set_val, int64_set_val, etc.) - list_val / set_val (RepeatedValue with nested Values) - map_val / struct_val (Map<string, Value>) - map_list_val / struct_list_val (MapList) Add tests for all previously uncovered types and a float32 precision consistency test against MessageToDict. Signed-off-by: abhijeet-dhumal <abhijeetdhumal652@gmail.com>

…nt set-type behavior Signed-off-by: abhijeet-dhumal <abhijeetdhumal652@gmail.com>

…p test Signed-off-by: abhijeet-dhumal <abhijeetdhumal652@gmail.com>

Signed-off-by: abhijeet-dhumal <abhijeetdhumal652@gmail.com>

bytes_val returned raw bytes which cause json.dumps TypeError when JSONResponse serializes the response. Base64-encode these values to match standard protobuf JSON encoding for bytes fields. Fixes Nikhil's review comment: bytes_val is still problem since you are using JSONResponse. Signed-off-by: abhijeet-dhumal <abhijeetdhumal652@gmail.com>

Signed-off-by: abhijeet-dhumal <abhijeetdhumal652@gmail.com>

ntkathole

looks good

…t-dev#6435) PR feast-dev#6015 replaced MessageToDict with a custom dict builder in feature_server.py, which incidentally fixed the crash caused by the removed float_precision kwarg in protobuf >= 7.34.0. Add explicit regression tests to prevent reintroduction: - Verify convert_response_to_dict never calls MessageToDict - Verify double precision round-trips without float_precision kwarg Fixes feast-dev#6435 Assisted-by: Claude Opus 4.6 Signed-off-by: Jonathan Wrede <wrede.jonathan00@gmail.com>

PR #6015 replaced MessageToDict with a custom dict builder in feature_server.py, which incidentally fixed the crash caused by the removed float_precision kwarg in protobuf >= 7.34.0. Add explicit regression tests to prevent reintroduction: - Verify convert_response_to_dict never calls MessageToDict - Verify double precision round-trips without float_precision kwarg Fixes #6435 Assisted-by: Claude Opus 4.6 Signed-off-by: Jonathan Wrede <wrede.jonathan00@gmail.com>

# [0.64.0](v0.63.0...v0.64.0) (2026-06-13) ### Bug Fixes * Add async_supported property to RedisOnlineStore ([9b088fe](9b088fe)) * Add missing feast init templates to operator CRD and enhance persistence documentation ([1941d4d](1941d4d)) * Allow to publish from reference branch ([5458ec8](5458ec8)) * API calls list ([4203eb7](4203eb7)) * **bigquery:** Enable list inference for parquet loads in offline_write_batch ([9243497](9243497)), closes [#5845](#5845) * Bump grpcio dependencies ([07b4782](07b4782)) * **compute-engine/local:** Honor field_mapping on join keys in dedup + join nodes ([#6395](#6395)) ([bd01824](bd01824)) * **dynamodb:** Avoid tag race condition by using diff-based tag updates ([#6479](#6479)) ([bad2b7d](bad2b7d)), closes [#6418](#6418) * **dynamodb:** Fix mypy type for _build_projection_expression return ([217b4da](217b4da)) * Fix intermittent async test failures for DynamoDB and Redis ([63c5eb1](63c5eb1)) * Fix mongodb blog title ([57d28d4](57d28d4)) * Fix shared SQL registry crash - avoid unnecessary UDF deserialization in proto cache building ([ac588d7](ac588d7)) * Fix SparkRetrievalJob.persist() failing for SparkSource ([209d7cd](209d7cd)) * Fixed formatting and image for mongo blog ([#6377](#6377)) ([f8389fb](f8389fb)) * Fixes for ray source ([7f592a4](7f592a4)) * **go:** skip registry refresh when cache_ttl_seconds <= 0 ([97ed40c](97ed40c)) * Handle array of strings columns in Athena materialization ([#6324](#6324)) ([4ed0278](4ed0278)) * make milvus VARCHAR max_length configurable, remove hardcoded 512 limit ([3b98c22](3b98c22)) * **operator:** Set appProtocol: grpc on registry gRPC Service ([#6367](#6367)) ([c9ae2b4](c9ae2b4)) * PyJWT 2.10+ added validation that rejects empty HMAC keys ([e756ffe](e756ffe)) * RemoteOnlineStore sends all features in a single HTTP request ([8f187dd](8f187dd)) * Remove registry proto dump to enforce RBAC and add permission checks to Commit/Refresh RPCs ([328431f](328431f)) * Remove selector migration job - no longer needed ([51c325e](51c325e)) * replace broken .claude skill symlink with correct relative path ([4541690](4541690)) * Replace selector label strip patch with migration Job for upgrade-safe selector uniqueness ([00dea50](00dea50)) * Scope feature view name conflict check to current project in file-based registry ([#6369](#6369)) ([a4fde83](a4fde83)), closes [#6209](#6209) * **snowflake:** Stop double-quoting connection identifiers ([#6462](#6462)) ([e914d59](e914d59)) * **spark:** S3/GCS PyArrow filesystem resolution for staging paths ([#6442](#6442)) ([ae50414](ae50414)) * **trino:** Clean up temporary entity tables after retrieval ([#6381](#6381)) ([d86b13d](d86b13d)), closes [#6306](#6306) * Update go-feature-server base image to Go 1.25 and fix operator Dockerfile COPY permissions ([86ef0bc](86ef0bc)) ### Features * [Backend] Data Quality Monitoring with native compute, multi-backend support, REST API, CLI ([#6202](#6202)) ([5458c37](5458c37)) * Add apache flink compute engine ([#6476](#6476)) ([9636d6a](9636d6a)) * Add demo noteboooks for users ([e362173](e362173)) * Add enabled/disabled toggle for feature views ([#6401](#6401)) ([5f1fa0d](5f1fa0d)), closes [#6395](#6395) * Add Label View to init template ([ec272d5](ec272d5)) * Add mTLS support to remote registry gRPC client ([#6474](#6474)) ([c9602d8](c9602d8)) * Add Prometheus gauges for FeatureStore installation telemetry ([#6354](#6354)) ([1b681b7](1b681b7)) * Adds registry REST API endpoints for managing entities, data sources, and feature views ([#6413](#6413)) ([f77bd1d](f77bd1d)) * Allow CRUD on entities, data sources, and feature views from UI ([#6412](#6412)) ([2321c07](2321c07)) * Allow default openlineage configuration ([#6467](#6467)) ([276b6df](276b6df)) * **bigquery:** Support DATE-type event timestamp columns ([#6362](#6362)) ([753dee5](753dee5)), closes [#2530](#2530) * **cli:** Add `feast projects delete` command (closes [#5095](#5095)) ([#6318](#6318)) ([1a4b96c](1a4b96c)) * Data Quality Monitoring added in feast UI ([#6422](#6422)) ([fa271be](fa271be)) * **dynamodb:** Use ProjectionExpression when requested_features is set ([0adc906](0adc906)), closes [#6058](#6058) * Enhance DataSource and FeatureView modals with error handling and submission states ([96d7169](96d7169)) * Expose registry endpoints on feature server for MCP access ([f77981c](f77981c)) * Feast First-Class LabelView Implementation ([#6292](#6292)) ([c0e7e5d](c0e7e5d)) * Feast-MLflow Integration ([#6235](#6235)) ([7279c75](7279c75)) * Operational metrics for offline store and SOX metrics for both ([#6340](#6340)) ([65b1b80](65b1b80)) * Pre-compute feature service ([8011550](8011550)) * REST API-backed UI for RBAC compatibility and per-page lazy loading ([#6414](#6414)) ([6ae80af](6ae80af)) * Support non-string map key types ([#6382](#6382)) ([#6383](#6383)) ([728aa2e](728aa2e)) * Update FeatureStore CRD with DRA Fields ([01241e4](01241e4)) ### Performance Improvements * Cache feature view resolution in get_online_features to reduce per-request overhead ([55c2f18](55c2f18)) * Optimize feature serving latency with batched async Redis, cached checks fix ([103809a](103809a)) * Replace MessageToDict with optimized custom dict builder ([#6015](#6015)) ([9902064](9902064))

abhijeet-dhumal requested a review from a team as a code owner February 24, 2026 06:27