create an isolated child process to run unsafe code and CFFI, handle …

…any fatal errors within the process as panics.

go.mod

@@ -43,6 +43,8 @@ require (
 )
 
 require github.com/rs/zerolog v1.21.0
+require github.com/jbenet/goprocess v0.1.4
+require github.com/ianlancetaylor/cgosymbolizer v0.0.0-20230801000641-8736a9d41aaa
 
 require (
 	github.com/JohnCGriffin/overflow v0.0.0-20211019200055-46fa312c352c // indirect

go.sum

@@ -226,8 +226,13 @@ github.com/hashicorp/memberlist v0.1.3/go.mod h1:ajVTdAv/9Im8oMAAj5G31PhhMCZJV2p
 github.com/hashicorp/serf v0.8.2/go.mod h1:6hOLApaqBFA1NXqRQAsxw9QxuDEvNxSQRwA/JwenrHc=
 github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=
 github.com/hudl/fargo v1.3.0/go.mod h1:y3CKSmjA+wD2gak7sUSXTAoopbhU08POFhmITJgmKTg=
+github.com/ianlancetaylor/cgosymbolizer v0.0.0-20230801000641-8736a9d41aaa h1:FEZID0R3+pkWLvjmZJ2iL+SZTcb2+/PgVvoyQss/q/I=
+github.com/ianlancetaylor/cgosymbolizer v0.0.0-20230801000641-8736a9d41aaa/go.mod h1:DvXTE/K/RtHehxU8/GtDs4vFtfw64jJ3PaCnFri8CRg=
 github.com/inconshreveable/mousetrap v1.0.0/go.mod h1:PxqpIevigyE2G7u3NXJIT2ANytuPF1OarO4DADm73n8=
 github.com/influxdata/influxdb1-client v0.0.0-20191209144304-8bf82d3c094d/go.mod h1:qj24IKcXYK6Iy9ceXlo3Tc+vtHo9lIhSX5JddghvEPo=
+github.com/jbenet/go-cienv v0.1.0/go.mod h1:TqNnHUmJgXau0nCzC7kXWeotg3J9W34CUv5Djy1+FlA=
+github.com/jbenet/goprocess v0.1.4 h1:DRGOFReOMqqDNXwW70QkacFW0YN9QnwLV0Vqk+3oU0o=
+github.com/jbenet/goprocess v0.1.4/go.mod h1:5yspPrukOVuOLORacaBi858NqyClJPQxYZlqdZVfqY4=
 github.com/jmespath/go-jmespath v0.0.0-20180206201540-c2b33e8439af/go.mod h1:Nht3zPeWKUH0NzdCt2Blrr5ys8VGpn0CEB0cQHVjt7k=
 github.com/jonboulle/clockwork v0.1.0/go.mod h1:Ii8DK3G1RaLaWxj9trq07+26W01tbo22gdxWY5EU2bo=
 github.com/json-iterator/go v1.1.6/go.mod h1:+SdeFBvtyEkXs7REEP0seUULqWtbJapLOCVDaaPEHmU=

go/internal/feast/transformation/transformation.go

@@ -3,7 +3,9 @@ package transformation
 import (
 	"errors"
 	"fmt"
+	"github.com/jbenet/goprocess"
 	"runtime"
+	"runtime/debug"
 	"strings"
 	"unsafe"
 
@@ -19,6 +21,8 @@ import (
 	"github.com/feast-dev/feast/go/protos/feast/serving"
 	prototypes "github.com/feast-dev/feast/go/protos/feast/types"
 	"github.com/feast-dev/feast/go/types"
+
+	_ "github.com/ianlancetaylor/cgosymbolizer"
 )
 
 /*
@@ -28,6 +32,10 @@ Each record batch is being passed as two pointers: pointer to array (data) and p
 Python function is expected to return number of rows added to the output record batch.
 */
 type TransformationCallback func(ODFVName string, inputArrPtr, inputSchemaPtr, outArrPtr, outSchemaPtr uintptr, fullFeatureNames bool) int
+type TransformChannel struct {
+	outRecord arrow.Record
+	err       error
+}
 
 func AugmentResponseWithOnDemandTransforms(
 	onDemandFeatureViews []*model.OnDemandFeatureView,
@@ -63,7 +71,6 @@ func AugmentResponseWithOnDemandTransforms(
 		for _, vector := range features {
 			retrievedFeatures[vector.Name] = vector.Values
 		}
-
 		onDemandFeatures, err := CallTransformations(
 			odfv,
 			retrievedFeatures,
@@ -95,40 +102,6 @@ func CallTransformations(
 	fullFeatureNames bool,
 ) ([]*onlineserving.FeatureVector, error) {
 
-	inputArr := cdata.CArrowArray{}
-	inputSchema := cdata.CArrowSchema{}
-
-	outArr := cdata.CArrowArray{}
-	outSchema := cdata.CArrowSchema{}
-
-	defer cdata.ReleaseCArrowArray(&inputArr)
-	defer cdata.ReleaseCArrowArray(&outArr)
-	defer cdata.ReleaseCArrowSchema(&inputSchema)
-	defer cdata.ReleaseCArrowSchema(&outSchema)
-
-	inputArrPtr := uintptr(unsafe.Pointer(&inputArr))
-	inputSchemaPtr := uintptr(unsafe.Pointer(&inputSchema))
-
-	outArrPtr := uintptr(unsafe.Pointer(&outArr))
-	outSchemaPtr := uintptr(unsafe.Pointer(&outSchema))
-
-	inputFields := make([]arrow.Field, 0)
-	inputColumns := make([]arrow.Array, 0)
-	for name, arr := range retrievedFeatures {
-		inputFields = append(inputFields, arrow.Field{Name: name, Type: arr.DataType()})
-		inputColumns = append(inputColumns, arr)
-	}
-	for name, arr := range requestContext {
-		inputFields = append(inputFields, arrow.Field{Name: name, Type: arr.DataType()})
-		inputColumns = append(inputColumns, arr)
-	}
-
-	inputRecord := array.NewRecord(arrow.NewSchema(inputFields, nil), inputColumns, int64(numRows))
-	defer inputRecord.Release()
-
-	cdata.ExportArrowRecordBatch(inputRecord, &inputArr, &inputSchema)
-
-	// Recover from a panic from FFI so the server doesn't crash
 	var err error
 	defer func() {
 		if e := recover(); e != nil {
@@ -146,19 +119,67 @@ func CallTransformations(
 			}
 		}
 	}()
-	ret := callback(featureView.Base.Name, inputArrPtr, inputSchemaPtr, outArrPtr, outSchemaPtr, fullFeatureNames)
+	transformResp := make(chan TransformChannel)
+	proc := goprocess.Background()
+	proc.Go(func(p goprocess.Process) {
+		debug.SetPanicOnFault(true)
+		inputArr := cdata.CArrowArray{}
+		inputSchema := cdata.CArrowSchema{}
+
+		outArr := cdata.CArrowArray{}
+		outSchema := cdata.CArrowSchema{}
+
+		defer cdata.ReleaseCArrowArray(&inputArr)
+		defer cdata.ReleaseCArrowArray(&outArr)
+		defer cdata.ReleaseCArrowSchema(&inputSchema)
+		defer cdata.ReleaseCArrowSchema(&outSchema)
+
+		inputArrPtr := uintptr(unsafe.Pointer(&inputArr))
+		inputSchemaPtr := uintptr(unsafe.Pointer(&inputSchema))
+
+		outArrPtr := uintptr(unsafe.Pointer(&outArr))
+		outSchemaPtr := uintptr(unsafe.Pointer(&outSchema))
+
+		inputFields := make([]arrow.Field, 0)
+		inputColumns := make([]arrow.Array, 0)
+		for name, arr := range retrievedFeatures {
+			inputFields = append(inputFields, arrow.Field{Name: name, Type: arr.DataType()})
+			inputColumns = append(inputColumns, arr)
+		}
+		for name, arr := range requestContext {
+			inputFields = append(inputFields, arrow.Field{Name: name, Type: arr.DataType()})
+			inputColumns = append(inputColumns, arr)
+		}
 
-	if ret != numRows {
-		return nil, errors.New("python transformation callback failed")
-	}
+		inputRecord := array.NewRecord(arrow.NewSchema(inputFields, nil), inputColumns, int64(numRows))
+		defer inputRecord.Release()
+
+		cdata.ExportArrowRecordBatch(inputRecord, &inputArr, &inputSchema)
+
+		ret := callback(featureView.Base.Name, inputArrPtr, inputSchemaPtr, outArrPtr, outSchemaPtr, fullFeatureNames)
 
-	outRecord, err := cdata.ImportCRecordBatch(&outArr, &outSchema)
+		if ret != numRows {
+			transformResp <- TransformChannel{nil, errors.New("python transformation callback failed")}
+		} else {
+			outRecord, err := cdata.ImportCRecordBatch(&outArr, &outSchema)
+			if err != nil {
+				transformResp <- TransformChannel{nil, err}
+			} else {
+				transformResp <- TransformChannel{outRecord, nil}
+			}
+		}
+	})
+	err = proc.Close()
 	if err != nil {
 		return nil, err
 	}
+	resp := <-transformResp
+	if resp.err != nil {
+		return nil, resp.err
+	}
 
 	result := make([]*onlineserving.FeatureVector, 0)
-	for idx, field := range outRecord.Schema().Fields() {
+	for idx, field := range resp.outRecord.Schema().Fields() {
 		dropFeature := true
 
 		if featureView.Base.Projection != nil {
@@ -192,7 +213,7 @@ func CallTransformations(
 
 		result = append(result, &onlineserving.FeatureVector{
 			Name:       field.Name,
-			Values:     outRecord.Column(idx),
+			Values:     resp.outRecord.Column(idx),
 			Statuses:   statuses,
 			Timestamps: timestamps,
 		})