feat: Use a daemon thread to monitor the go feature server exclusively

.github/workflows/linter.yml

@@ -64,6 +64,6 @@ jobs:
         run: |
           pip install --upgrade "pip>=21.3.1"
       - name: Install dependencies
-        run:  make install-go-ci-dependencies
+        run:  make install-go-proto-dependencies
       - name: Lint go
         run: make lint-go

.github/workflows/unit_tests.yml

@@ -84,7 +84,7 @@ jobs:
         with:
           go-version: 1.17.7
       - name: Install dependencies
-        run: make install-go-ci-dependencies
+        run: make install-go-proto-dependencies
       - name: Compile protos
         run: make compile-protos-go
       - name: Test

Makefile

@@ -35,7 +35,7 @@ build: protos build-java build-docker build-html
 
 # Python SDK
 
-install-python-ci-dependencies: install-go-ci-dependencies
+install-python-ci-dependencies: install-go-proto-dependencies
 	cd sdk/python && python -m piptools sync requirements/py$(PYTHON)-ci-requirements.txt
 	cd sdk/python && COMPILE_GO=true python setup.py develop
 
@@ -125,19 +125,21 @@ build-java-no-tests:
 
 # Go SDK
 
-install-go-ci-dependencies:
+install-go-proto-dependencies:
 	go install google.golang.org/protobuf/cmd/[email protected]
 	go install google.golang.org/grpc/cmd/[email protected]
 
-compile-protos-go: install-go-ci-dependencies
+install-protoc-dependencies:
 	pip install grpcio-tools==1.34.0
+
+compile-protos-go: install-go-proto-dependencies install-protoc-dependencies
 	python sdk/python/setup.py build_go_protos
 
 compile-go-feature-server: compile-protos-go
 	go mod tidy
 	go build -o ${ROOT_DIR}/sdk/python/feast/binaries/goserver github.com/feast-dev/feast/go/cmd/goserver
 
-test-go: install-go-ci-dependencies
+test-go: compile-protos-go
 	go test ./...
 
 format-go:

go/cmd/goserver/main.go

@@ -23,7 +23,6 @@ type FeastEnvConfig struct {
 }
 
 // TODO: Add a proper logging library such as https://github.com/Sirupsen/logrus
-
 func main() {
 
 	var feastEnvConfig FeastEnvConfig

sdk/python/feast/feature_store.py

@@ -108,10 +108,7 @@ class FeatureStore:
 
     @log_exceptions
     def __init__(
-        self,
-        repo_path: Optional[str] = None,
-        config: Optional[RepoConfig] = None,
-        go_server_use_thread: bool = False,
+        self, repo_path: Optional[str] = None, config: Optional[RepoConfig] = None,
     ):
         """
         Creates a FeatureStore object.
@@ -135,7 +132,6 @@ def __init__(
         self._registry._initialize_registry()
         self._provider = get_provider(self.config, self.repo_path)
         self._go_server = None
-        self._go_server_use_thread = go_server_use_thread
 
     @log_exceptions
     def version(self) -> str:
@@ -733,6 +729,10 @@ def apply(
                     service.name, project=self.project, commit=False
                 )
 
+        # If a go server is running, kill it so that it can be recreated in `update_infra` with
+        # the latest registry state.
+        self.kill_go_server()
+
         self._get_provider().update_infra(
             project=self.project,
             tables_to_delete=views_to_delete if not partial else [],
@@ -754,6 +754,8 @@ def teardown(self):
 
         entities = self.list_entities()
 
+        self.kill_go_server()
+
         self._get_provider().teardown_infra(self.project, tables, entities)
         self._registry.teardown()
 
@@ -1233,11 +1235,8 @@ def get_online_features(
         if self.config.go_feature_server:
             # Lazily start the go server on the first request
             if self._go_server is None:
-                self._go_server = GoServer(
-                    str(self.repo_path.absolute()),
-                    self.config,
-                    self._go_server_use_thread,
-                )
+                self._go_server = GoServer(str(self.repo_path.absolute()), self.config,)
+                self._go_server._shared_connection._check_grpc_connection()
             return self._go_server.get_online_features(
                 features, columnar, full_feature_names
             )
@@ -1860,12 +1859,7 @@ def serve_transformations(self, port: int) -> None:
     def kill_go_server(self):
         if self._go_server:
             self._go_server.kill_go_server_explicitly()
-
-    def set_go_server_use_thread(self, use: bool):
-        if self._go_server:
-            self._go_server.set_use_thread(use)
-        else:
-            self._go_server_use_thread = use
+            self._go_server = None
 
 
 def _validate_entity_values(join_key_values: Dict[str, List[Value]]):