Kafka exporter (#3840)

* abstract db interface, kafka build, work in progress * checkpoint * Merge branch 'master' of github.com:prysmaticlabs/prysm into es-exporter * feature flag * move passthrough * flag change * gofmt * Merge branch 'master' of github.com:prysmaticlabs/prysm into es-exporter * missing db methods * Merge branch 'master' of github.com:prysmaticlabs/prysm into es-exporter * fix interface * Merge branch 'master' of github.com:prysmaticlabs/prysm into es-exporter * Merge branch 'master' of github.com:prysmaticlabs/prysm into es-exporter * Merge branch 'master' of github.com:prysmaticlabs/prysm into es-exporter * try using cmake built from source * lint godocs * lint godocs * lint godocs * Update BUILD.bazel * Merge branch 'master' into es-exporter * Merge branch 'master' into es-exporter * Merge branch 'master' into es-exporter * Merge branch 'master' of github.com:prysmaticlabs/prysm into es-exporter * gaz
2024-12-22 03:30:35 +00:00 · 2019-12-05 18:05:58 -08:00 · 2019-12-05 18:05:58 -08:00 · d3375d98a8
commit d3375d98a8
parent 9d4c7cb4f7
15 changed files with 631 additions and 91 deletions
--- a/BUILD.bazel
+++ b/BUILD.bazel
@ -137,3 +137,9 @@ common_files = {
    ),
    tags = ["manual"],
 ) for pair in binary_targets]
+
+toolchain(
+    name = "built_cmake_toolchain",
+    toolchain = "@rules_foreign_cc//tools/build_defs/native_tools:built_cmake",
+    toolchain_type = "@rules_foreign_cc//tools/build_defs:cmake_toolchain",
+)
--- a/31
+++ b/31
@ -217,6 +217,28 @@ load("@com_google_protobuf//:protobuf_deps.bzl", "protobuf_deps")

 protobuf_deps()

+# Group the sources of the library so that CMake rule have access to it
+all_content = """filegroup(name = "all", srcs = glob(["**"]), visibility = ["//visibility:public"])"""
+
+http_archive(
+    name = "rules_foreign_cc",
+    strip_prefix = "rules_foreign_cc-master",
+    url = "https://github.com/bazelbuild/rules_foreign_cc/archive/master.zip",
+)
+
+load("@rules_foreign_cc//:workspace_definitions.bzl", "rules_foreign_cc_dependencies")
+
+rules_foreign_cc_dependencies([
+    "@prysm//:built_cmake_toolchain",
+])
+
+http_archive(
+    name = "librdkafka",
+    build_file_content = all_content,
+    strip_prefix = "librdkafka-1.2.1",
+    urls = ["https://github.com/edenhill/librdkafka/archive/v1.2.1.tar.gz"],
+)
+
 # External dependencies

 go_repository(
@ -1288,6 +1310,15 @@ go_repository(
    version = "v0.0.0-20191002040644-a1355ae1e2c3",
 )

+go_repository(
+    name = "in_gopkg_confluentinc_confluent_kafka_go_v1",
+    importpath = "gopkg.in/confluentinc/confluent-kafka-go.v1",
+    patch_args = ["-p1"],
+    patches = ["//third_party:in_gopkg_confluentinc_confluent_kafka_go_v1.patch"],
+    sum = "h1:roy97m/3wj9/o8OuU3sZ5wildk30ep38k2x8nhNbKrI=",
+    version = "v1.1.0",
+)
+
 go_repository(
    name = "com_github_naoina_toml",
    importpath = "github.com/naoina/toml",
--- a/beacon-chain/db/BUILD.bazel
+++ b/beacon-chain/db/BUILD.bazel
@ -12,11 +12,9 @@ go_library(
        "//tools:__subpackages__",
    ],
    deps = [
-        "//beacon-chain/db/filters:go_default_library",
+        "//beacon-chain/db/iface:go_default_library",
+        "//beacon-chain/db/kafka:go_default_library",
        "//beacon-chain/db/kv:go_default_library",
-        "//proto/beacon/p2p/v1:go_default_library",
-        "@com_github_ethereum_go_ethereum//common:go_default_library",
-        "@com_github_prysmaticlabs_ethereumapis//eth/v1alpha1:go_default_library",
        "@com_github_sirupsen_logrus//:go_default_library",
    ],
 )
--- a/beacon-chain/db/db.go
+++ b/beacon-chain/db/db.go
@ -1,91 +1,21 @@
 package db

 import (
-	"context"
-	"io"
-
-	"github.com/ethereum/go-ethereum/common"
-	ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
-	"github.com/prysmaticlabs/prysm/beacon-chain/db/filters"
+	"github.com/prysmaticlabs/prysm/beacon-chain/db/iface"
+	"github.com/prysmaticlabs/prysm/beacon-chain/db/kafka"
 	"github.com/prysmaticlabs/prysm/beacon-chain/db/kv"
-	pb "github.com/prysmaticlabs/prysm/proto/beacon/p2p/v1"
 )

 // Database defines the necessary methods for Prysm's eth2 backend which may
 // be implemented by any key-value or relational database in practice.
-type Database interface {
-	io.Closer
-	DatabasePath() string
-	ClearDB() error
-	// Backup and restore methods
-	Backup(ctx context.Context) error
-	// Attestation related methods.
-	AttestationsByDataRoot(ctx context.Context, attDataRoot [32]byte) ([]*ethpb.Attestation, error)
-	Attestations(ctx context.Context, f *filters.QueryFilter) ([]*ethpb.Attestation, error)
-	HasAttestation(ctx context.Context, attDataRoot [32]byte) bool
-	DeleteAttestation(ctx context.Context, attDataRoot [32]byte) error
-	DeleteAttestations(ctx context.Context, attDataRoots [][32]byte) error
-	SaveAttestation(ctx context.Context, att *ethpb.Attestation) error
-	SaveAttestations(ctx context.Context, atts []*ethpb.Attestation) error
-	// Block related methods.
-	Block(ctx context.Context, blockRoot [32]byte) (*ethpb.BeaconBlock, error)
-	HeadBlock(ctx context.Context) (*ethpb.BeaconBlock, error)
-	Blocks(ctx context.Context, f *filters.QueryFilter) ([]*ethpb.BeaconBlock, error)
-	BlockRoots(ctx context.Context, f *filters.QueryFilter) ([][32]byte, error)
-	HasBlock(ctx context.Context, blockRoot [32]byte) bool
-	DeleteBlock(ctx context.Context, blockRoot [32]byte) error
-	DeleteBlocks(ctx context.Context, blockRoots [][32]byte) error
-	SaveBlock(ctx context.Context, block *ethpb.BeaconBlock) error
-	SaveBlocks(ctx context.Context, blocks []*ethpb.BeaconBlock) error
-	SaveHeadBlockRoot(ctx context.Context, blockRoot [32]byte) error
-	SaveGenesisBlockRoot(ctx context.Context, blockRoot [32]byte) error
-	IsFinalizedBlock(ctx context.Context, blockRoot [32]byte) bool
-	// Validator related methods.
-	ValidatorIndex(ctx context.Context, publicKey [48]byte) (uint64, bool, error)
-	HasValidatorIndex(ctx context.Context, publicKey [48]byte) bool
-	DeleteValidatorIndex(ctx context.Context, publicKey [48]byte) error
-	SaveValidatorIndex(ctx context.Context, publicKey [48]byte, validatorIdx uint64) error
-	// State related methods.
-	State(ctx context.Context, blockRoot [32]byte) (*pb.BeaconState, error)
-	HeadState(ctx context.Context) (*pb.BeaconState, error)
-	GenesisState(ctx context.Context) (*pb.BeaconState, error)
-	SaveState(ctx context.Context, state *pb.BeaconState, blockRoot [32]byte) error
-	DeleteState(ctx context.Context, blockRoot [32]byte) error
-	DeleteStates(ctx context.Context, blockRoots [][32]byte) error
-	// Slashing operations.
-	ProposerSlashing(ctx context.Context, slashingRoot [32]byte) (*ethpb.ProposerSlashing, error)
-	AttesterSlashing(ctx context.Context, slashingRoot [32]byte) (*ethpb.AttesterSlashing, error)
-	SaveProposerSlashing(ctx context.Context, slashing *ethpb.ProposerSlashing) error
-	SaveAttesterSlashing(ctx context.Context, slashing *ethpb.AttesterSlashing) error
-	HasProposerSlashing(ctx context.Context, slashingRoot [32]byte) bool
-	HasAttesterSlashing(ctx context.Context, slashingRoot [32]byte) bool
-	DeleteProposerSlashing(ctx context.Context, slashingRoot [32]byte) error
-	DeleteAttesterSlashing(ctx context.Context, slashingRoot [32]byte) error
-	// Block operations.
-	VoluntaryExit(ctx context.Context, exitRoot [32]byte) (*ethpb.VoluntaryExit, error)
-	SaveVoluntaryExit(ctx context.Context, exit *ethpb.VoluntaryExit) error
-	HasVoluntaryExit(ctx context.Context, exitRoot [32]byte) bool
-	DeleteVoluntaryExit(ctx context.Context, exitRoot [32]byte) error
-	// Checkpoint operations.
-	JustifiedCheckpoint(ctx context.Context) (*ethpb.Checkpoint, error)
-	FinalizedCheckpoint(ctx context.Context) (*ethpb.Checkpoint, error)
-	SaveJustifiedCheckpoint(ctx context.Context, checkpoint *ethpb.Checkpoint) error
-	SaveFinalizedCheckpoint(ctx context.Context, checkpoint *ethpb.Checkpoint) error
-	// Archival data handlers for storing/retrieving historical beacon node information.
-	ArchivedActiveValidatorChanges(ctx context.Context, epoch uint64) (*pb.ArchivedActiveSetChanges, error)
-	SaveArchivedActiveValidatorChanges(ctx context.Context, epoch uint64, changes *pb.ArchivedActiveSetChanges) error
-	ArchivedCommitteeInfo(ctx context.Context, epoch uint64) (*pb.ArchivedCommitteeInfo, error)
-	SaveArchivedCommitteeInfo(ctx context.Context, epoch uint64, info *pb.ArchivedCommitteeInfo) error
-	ArchivedBalances(ctx context.Context, epoch uint64) ([]uint64, error)
-	SaveArchivedBalances(ctx context.Context, epoch uint64, balances []uint64) error
-	ArchivedValidatorParticipation(ctx context.Context, epoch uint64) (*ethpb.ValidatorParticipation, error)
-	SaveArchivedValidatorParticipation(ctx context.Context, epoch uint64, part *ethpb.ValidatorParticipation) error
-	// Deposit contract related handlers.
-	DepositContractAddress(ctx context.Context) ([]byte, error)
-	SaveDepositContractAddress(ctx context.Context, addr common.Address) error
-}
+type Database = iface.Database

 // NewDB initializes a new DB.
 func NewDB(dirPath string) (Database, error) {
-	return kv.NewKVStore(dirPath)
+	db, err := kv.NewKVStore(dirPath)
+	if err != nil {
+		return nil, err
+	}
+
+	return kafka.Wrap(db)
 }
--- a/beacon-chain/db/iface/BUILD.bazel
+++ b/beacon-chain/db/iface/BUILD.bazel
@ -0,0 +1,15 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = ["interface.go"],
+    importpath = "github.com/prysmaticlabs/prysm/beacon-chain/db/iface",
+    # Other packages must use github.com/prysmaticlabs/prysm/beacon-chain/db.Database alias.
+    visibility = ["//beacon-chain/db:__subpackages__"],
+    deps = [
+        "//beacon-chain/db/filters:go_default_library",
+        "//proto/beacon/p2p/v1:go_default_library",
+        "@com_github_ethereum_go_ethereum//common:go_default_library",
+        "@com_github_prysmaticlabs_ethereumapis//eth/v1alpha1:go_default_library",
+    ],
+)
--- a/beacon-chain/db/iface/interface.go
+++ b/beacon-chain/db/iface/interface.go
@ -0,0 +1,86 @@
+// Package iface exists to prevent circular dependencies when implementing the database interface.
+package iface
+
+import (
+	"context"
+	"io"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/prysmaticlabs/prysm/beacon-chain/db/filters"
+	"github.com/prysmaticlabs/prysm/proto/beacon/p2p/v1"
+	eth "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
+)
+
+// Database defines the necessary methods for Prysm's eth2 backend which may
+// be implemented by any key-value or relational database in practice.
+type Database interface {
+	io.Closer
+	DatabasePath() string
+	ClearDB() error
+	// Backup and restore methods
+	Backup(ctx context.Context) error
+	// Attestation related methods.
+	AttestationsByDataRoot(ctx context.Context, attDataRoot [32]byte) ([]*eth.Attestation, error)
+	Attestations(ctx context.Context, f *filters.QueryFilter) ([]*eth.Attestation, error)
+	HasAttestation(ctx context.Context, attDataRoot [32]byte) bool
+	DeleteAttestation(ctx context.Context, attDataRoot [32]byte) error
+	DeleteAttestations(ctx context.Context, attDataRoots [][32]byte) error
+	SaveAttestation(ctx context.Context, att *eth.Attestation) error
+	SaveAttestations(ctx context.Context, atts []*eth.Attestation) error
+	// Block related methods.
+	Block(ctx context.Context, blockRoot [32]byte) (*eth.BeaconBlock, error)
+	HeadBlock(ctx context.Context) (*eth.BeaconBlock, error)
+	Blocks(ctx context.Context, f *filters.QueryFilter) ([]*eth.BeaconBlock, error)
+	BlockRoots(ctx context.Context, f *filters.QueryFilter) ([][32]byte, error)
+	HasBlock(ctx context.Context, blockRoot [32]byte) bool
+	DeleteBlock(ctx context.Context, blockRoot [32]byte) error
+	DeleteBlocks(ctx context.Context, blockRoots [][32]byte) error
+	SaveBlock(ctx context.Context, block *eth.BeaconBlock) error
+	SaveBlocks(ctx context.Context, blocks []*eth.BeaconBlock) error
+	SaveHeadBlockRoot(ctx context.Context, blockRoot [32]byte) error
+	SaveGenesisBlockRoot(ctx context.Context, blockRoot [32]byte) error
+	IsFinalizedBlock(ctx context.Context, blockRoot [32]byte) bool
+	// Validator related methods.
+	ValidatorIndex(ctx context.Context, publicKey [48]byte) (uint64, bool, error)
+	HasValidatorIndex(ctx context.Context, publicKey [48]byte) bool
+	DeleteValidatorIndex(ctx context.Context, publicKey [48]byte) error
+	SaveValidatorIndex(ctx context.Context, publicKey [48]byte, validatorIdx uint64) error
+	// State related methods.
+	State(ctx context.Context, blockRoot [32]byte) (*ethereum_beacon_p2p_v1.BeaconState, error)
+	HeadState(ctx context.Context) (*ethereum_beacon_p2p_v1.BeaconState, error)
+	GenesisState(ctx context.Context) (*ethereum_beacon_p2p_v1.BeaconState, error)
+	SaveState(ctx context.Context, state *ethereum_beacon_p2p_v1.BeaconState, blockRoot [32]byte) error
+	DeleteState(ctx context.Context, blockRoot [32]byte) error
+	DeleteStates(ctx context.Context, blockRoots [][32]byte) error
+	// Slashing operations.
+	ProposerSlashing(ctx context.Context, slashingRoot [32]byte) (*eth.ProposerSlashing, error)
+	AttesterSlashing(ctx context.Context, slashingRoot [32]byte) (*eth.AttesterSlashing, error)
+	SaveProposerSlashing(ctx context.Context, slashing *eth.ProposerSlashing) error
+	SaveAttesterSlashing(ctx context.Context, slashing *eth.AttesterSlashing) error
+	HasProposerSlashing(ctx context.Context, slashingRoot [32]byte) bool
+	HasAttesterSlashing(ctx context.Context, slashingRoot [32]byte) bool
+	DeleteProposerSlashing(ctx context.Context, slashingRoot [32]byte) error
+	DeleteAttesterSlashing(ctx context.Context, slashingRoot [32]byte) error
+	// Block operations.
+	VoluntaryExit(ctx context.Context, exitRoot [32]byte) (*eth.VoluntaryExit, error)
+	SaveVoluntaryExit(ctx context.Context, exit *eth.VoluntaryExit) error
+	HasVoluntaryExit(ctx context.Context, exitRoot [32]byte) bool
+	DeleteVoluntaryExit(ctx context.Context, exitRoot [32]byte) error
+	// Checkpoint operations.
+	JustifiedCheckpoint(ctx context.Context) (*eth.Checkpoint, error)
+	FinalizedCheckpoint(ctx context.Context) (*eth.Checkpoint, error)
+	SaveJustifiedCheckpoint(ctx context.Context, checkpoint *eth.Checkpoint) error
+	SaveFinalizedCheckpoint(ctx context.Context, checkpoint *eth.Checkpoint) error
+	// Archival data handlers for storing/retrieving historical beacon node information.
+	ArchivedActiveValidatorChanges(ctx context.Context, epoch uint64) (*ethereum_beacon_p2p_v1.ArchivedActiveSetChanges, error)
+	SaveArchivedActiveValidatorChanges(ctx context.Context, epoch uint64, changes *ethereum_beacon_p2p_v1.ArchivedActiveSetChanges) error
+	ArchivedCommitteeInfo(ctx context.Context, epoch uint64) (*ethereum_beacon_p2p_v1.ArchivedCommitteeInfo, error)
+	SaveArchivedCommitteeInfo(ctx context.Context, epoch uint64, info *ethereum_beacon_p2p_v1.ArchivedCommitteeInfo) error
+	ArchivedBalances(ctx context.Context, epoch uint64) ([]uint64, error)
+	SaveArchivedBalances(ctx context.Context, epoch uint64, balances []uint64) error
+	ArchivedValidatorParticipation(ctx context.Context, epoch uint64) (*eth.ValidatorParticipation, error)
+	SaveArchivedValidatorParticipation(ctx context.Context, epoch uint64, part *eth.ValidatorParticipation) error
+	// Deposit contract related handlers.
+	DepositContractAddress(ctx context.Context) ([]byte, error)
+	SaveDepositContractAddress(ctx context.Context, addr common.Address) error
+}
--- a/beacon-chain/db/kafka/BUILD.bazel
+++ b/beacon-chain/db/kafka/BUILD.bazel
@ -0,0 +1,26 @@
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "go_default_library",
+    srcs = [
+        "export_wrapper.go",
+        "passthrough.go",
+    ],
+    importpath = "github.com/prysmaticlabs/prysm/beacon-chain/db/kafka",
+    visibility = ["//beacon-chain/db:__pkg__"],
+    deps = [
+        "//beacon-chain/db/filters:go_default_library",
+        "//beacon-chain/db/iface:go_default_library",
+        "//proto/beacon/p2p/v1:go_default_library",
+        "//shared/featureconfig:go_default_library",
+        "//shared/traceutil:go_default_library",
+        "@com_github_ethereum_go_ethereum//common:go_default_library",
+        "@com_github_golang_protobuf//jsonpb:go_default_library_gen",
+        "@com_github_golang_protobuf//proto:go_default_library",
+        "@com_github_prysmaticlabs_ethereumapis//eth/v1alpha1:go_default_library",
+        "@com_github_prysmaticlabs_go_ssz//:go_default_library",
+        "@com_github_sirupsen_logrus//:go_default_library",
+        "@in_gopkg_confluentinc_confluent_kafka_go_v1//kafka:go_default_library",
+        "@io_opencensus_go//trace:go_default_library",
+    ],
+)
--- a/beacon-chain/db/kafka/export_wrapper.go
+++ b/beacon-chain/db/kafka/export_wrapper.go
@ -0,0 +1,124 @@
+package kafka
+
+import (
+	"bytes"
+	"context"
+
+	"github.com/golang/protobuf/jsonpb"
+	"github.com/golang/protobuf/proto"
+	"github.com/prysmaticlabs/go-ssz"
+	"github.com/prysmaticlabs/prysm/beacon-chain/db/iface"
+	eth "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
+	"github.com/prysmaticlabs/prysm/shared/featureconfig"
+	"github.com/prysmaticlabs/prysm/shared/traceutil"
+	"github.com/sirupsen/logrus"
+	"go.opencensus.io/trace"
+	"gopkg.in/confluentinc/confluent-kafka-go.v1/kafka"
+)
+
+var _ = iface.Database(&Exporter{})
+var log = logrus.WithField("prefix", "exporter")
+var marshaler = &jsonpb.Marshaler{}
+
+// Exporter wraps a database interface and exports certain objects to kafka topics.
+type Exporter struct {
+	db iface.Database
+	p  *kafka.Producer
+}
+
+// Wrap the db with kafka exporter. If the feature flag is not enabled, this service does not wrap
+// the database, but returns the underlying database pointer itself.
+func Wrap(db iface.Database) (iface.Database, error) {
+	if featureconfig.Get().KafkaBootstrapServers == "" {
+		return db, nil
+	}
+
+	p, err := kafka.NewProducer(&kafka.ConfigMap{"bootstrap.servers": featureconfig.Get().KafkaBootstrapServers})
+	if err != nil {
+		return nil, err
+	}
+
+	return &Exporter{db: db, p: p}, nil
+}
+
+func (e Exporter) publish(ctx context.Context, topic string, msg proto.Message) error {
+	ctx, span := trace.StartSpan(ctx, "kafka.publish")
+	defer span.End()
+
+	buf := bytes.NewBuffer(nil)
+	if err := marshaler.Marshal(buf, msg); err != nil {
+		traceutil.AnnotateError(span, err)
+		return err
+	}
+
+	key, err := ssz.HashTreeRoot(msg)
+	if err != nil {
+		traceutil.AnnotateError(span, err)
+		return err
+	}
+
+	if err := e.p.Produce(&kafka.Message{
+		TopicPartition: kafka.TopicPartition{
+			Topic: &topic,
+		},
+		Value: buf.Bytes(),
+		Key:   key[:],
+	}, nil); err != nil {
+		traceutil.AnnotateError(span, err)
+		return err
+	}
+	return nil
+}
+
+// Close closes kafka producer and underlying db.
+func (e Exporter) Close() error {
+	e.p.Close()
+	return e.db.Close()
+}
+
+// SaveAttestation publishes to the kafka topic for attestations.
+func (e Exporter) SaveAttestation(ctx context.Context, att *eth.Attestation) error {
+	go func() {
+		if err := e.publish(ctx, "beacon_attestation", att); err != nil {
+			log.WithError(err).Error("Failed to publish attestation")
+		}
+	}()
+
+	return e.db.SaveAttestation(ctx, att)
+}
+
+// SaveAttestations publishes to the kafka topic for beacon attestations.
+func (e Exporter) SaveAttestations(ctx context.Context, atts []*eth.Attestation) error {
+	go func() {
+		for _, att := range atts {
+			if err := e.publish(ctx, "beacon_attestation", att); err != nil {
+				log.WithError(err).Error("Failed to publish attestation")
+			}
+		}
+	}()
+	return e.db.SaveAttestations(ctx, atts)
+}
+
+// SaveBlock publishes to the kafka topic for beacon blocks.
+func (e Exporter) SaveBlock(ctx context.Context, block *eth.BeaconBlock) error {
+	go func() {
+		if err := e.publish(ctx, "beacon_block", block); err != nil {
+			log.WithError(err).Error("Failed to publish block")
+		}
+	}()
+
+	return e.db.SaveBlock(ctx, block)
+}
+
+// SaveBlocks publishes to the kafka topic for beacon blocks.
+func (e Exporter) SaveBlocks(ctx context.Context, blocks []*eth.BeaconBlock) error {
+	go func() {
+		for _, block := range blocks {
+			if err := e.publish(ctx, "beacon_block", block); err != nil {
+				log.WithError(err).Error("Failed to publish block")
+			}
+		}
+	}()
+
+	return e.db.SaveBlocks(ctx, blocks)
+}
--- a/beacon-chain/db/kafka/passthrough.go
+++ b/beacon-chain/db/kafka/passthrough.go
@ -0,0 +1,280 @@
+package kafka
+
+import (
+	"context"
+
+	"github.com/ethereum/go-ethereum/common"
+	"github.com/prysmaticlabs/prysm/beacon-chain/db/filters"
+	ethereum_beacon_p2p_v1 "github.com/prysmaticlabs/prysm/proto/beacon/p2p/v1"
+	eth "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
+)
+
+// DatabasePath -- passthrough.
+func (e Exporter) DatabasePath() string {
+	return e.db.DatabasePath()
+}
+
+// ClearDB -- passthrough.
+func (e Exporter) ClearDB() error {
+	return e.db.ClearDB()
+}
+
+// Backup -- passthrough.
+func (e Exporter) Backup(ctx context.Context) error {
+	return e.db.Backup(ctx)
+}
+
+// AttestationsByDataRoot -- passthrough.
+func (e Exporter) AttestationsByDataRoot(ctx context.Context, attDataRoot [32]byte) ([]*eth.Attestation, error) {
+	return e.db.AttestationsByDataRoot(ctx, attDataRoot)
+}
+
+// Attestations -- passthrough.
+func (e Exporter) Attestations(ctx context.Context, f *filters.QueryFilter) ([]*eth.Attestation, error) {
+	return e.db.Attestations(ctx, f)
+}
+
+// HasAttestation -- passthrough.
+func (e Exporter) HasAttestation(ctx context.Context, attDataRoot [32]byte) bool {
+	return e.db.HasAttestation(ctx, attDataRoot)
+}
+
+// DeleteAttestation -- passthrough.
+func (e Exporter) DeleteAttestation(ctx context.Context, attDataRoot [32]byte) error {
+	return e.db.DeleteAttestation(ctx, attDataRoot)
+}
+
+// DeleteAttestations -- passthrough.
+func (e Exporter) DeleteAttestations(ctx context.Context, attDataRoots [][32]byte) error {
+	return e.db.DeleteAttestations(ctx, attDataRoots)
+}
+
+// Block -- passthrough.
+func (e Exporter) Block(ctx context.Context, blockRoot [32]byte) (*eth.BeaconBlock, error) {
+	return e.db.Block(ctx, blockRoot)
+}
+
+// HeadBlock -- passthrough.
+func (e Exporter) HeadBlock(ctx context.Context) (*eth.BeaconBlock, error) {
+	return e.db.HeadBlock(ctx)
+}
+
+// Blocks -- passthrough.
+func (e Exporter) Blocks(ctx context.Context, f *filters.QueryFilter) ([]*eth.BeaconBlock, error) {
+	return e.db.Blocks(ctx, f)
+}
+
+// BlockRoots -- passthrough.
+func (e Exporter) BlockRoots(ctx context.Context, f *filters.QueryFilter) ([][32]byte, error) {
+	return e.db.BlockRoots(ctx, f)
+}
+
+// HasBlock -- passthrough.
+func (e Exporter) HasBlock(ctx context.Context, blockRoot [32]byte) bool {
+	return e.db.HasBlock(ctx, blockRoot)
+}
+
+// DeleteBlock -- passthrough.
+func (e Exporter) DeleteBlock(ctx context.Context, blockRoot [32]byte) error {
+	return e.db.DeleteBlock(ctx, blockRoot)
+}
+
+// DeleteBlocks -- passthrough.
+func (e Exporter) DeleteBlocks(ctx context.Context, blockRoots [][32]byte) error {
+	return e.db.DeleteBlocks(ctx, blockRoots)
+}
+
+// ValidatorIndex -- passthrough.
+func (e Exporter) ValidatorIndex(ctx context.Context, publicKey [48]byte) (uint64, bool, error) {
+	return e.db.ValidatorIndex(ctx, publicKey)
+}
+
+// HasValidatorIndex -- passthrough.
+func (e Exporter) HasValidatorIndex(ctx context.Context, publicKey [48]byte) bool {
+	return e.db.HasValidatorIndex(ctx, publicKey)
+}
+
+// DeleteValidatorIndex -- passthrough.
+func (e Exporter) DeleteValidatorIndex(ctx context.Context, publicKey [48]byte) error {
+	return e.db.DeleteValidatorIndex(ctx, publicKey)
+}
+
+// State -- passthrough.
+func (e Exporter) State(ctx context.Context, blockRoot [32]byte) (*ethereum_beacon_p2p_v1.BeaconState, error) {
+	return e.db.State(ctx, blockRoot)
+}
+
+// HeadState -- passthrough.
+func (e Exporter) HeadState(ctx context.Context) (*ethereum_beacon_p2p_v1.BeaconState, error) {
+	return e.db.HeadState(ctx)
+}
+
+// GenesisState -- passthrough.
+func (e Exporter) GenesisState(ctx context.Context) (*ethereum_beacon_p2p_v1.BeaconState, error) {
+	return e.db.GenesisState(ctx)
+}
+
+// ProposerSlashing -- passthrough.
+func (e Exporter) ProposerSlashing(ctx context.Context, slashingRoot [32]byte) (*eth.ProposerSlashing, error) {
+	return e.db.ProposerSlashing(ctx, slashingRoot)
+}
+
+// AttesterSlashing -- passthrough.
+func (e Exporter) AttesterSlashing(ctx context.Context, slashingRoot [32]byte) (*eth.AttesterSlashing, error) {
+	return e.db.AttesterSlashing(ctx, slashingRoot)
+}
+
+// HasProposerSlashing -- passthrough.
+func (e Exporter) HasProposerSlashing(ctx context.Context, slashingRoot [32]byte) bool {
+	return e.db.HasProposerSlashing(ctx, slashingRoot)
+}
+
+// HasAttesterSlashing -- passthrough.
+func (e Exporter) HasAttesterSlashing(ctx context.Context, slashingRoot [32]byte) bool {
+	return e.db.HasAttesterSlashing(ctx, slashingRoot)
+}
+
+// DeleteProposerSlashing -- passthrough.
+func (e Exporter) DeleteProposerSlashing(ctx context.Context, slashingRoot [32]byte) error {
+	return e.db.DeleteProposerSlashing(ctx, slashingRoot)
+}
+
+// DeleteAttesterSlashing -- passthrough.
+func (e Exporter) DeleteAttesterSlashing(ctx context.Context, slashingRoot [32]byte) error {
+	return e.db.DeleteAttesterSlashing(ctx, slashingRoot)
+}
+
+// VoluntaryExit -- passthrough.
+func (e Exporter) VoluntaryExit(ctx context.Context, exitRoot [32]byte) (*eth.VoluntaryExit, error) {
+	return e.db.VoluntaryExit(ctx, exitRoot)
+}
+
+// HasVoluntaryExit -- passthrough.
+func (e Exporter) HasVoluntaryExit(ctx context.Context, exitRoot [32]byte) bool {
+	return e.db.HasVoluntaryExit(ctx, exitRoot)
+}
+
+// DeleteVoluntaryExit -- passthrough.
+func (e Exporter) DeleteVoluntaryExit(ctx context.Context, exitRoot [32]byte) error {
+	return e.db.DeleteVoluntaryExit(ctx, exitRoot)
+}
+
+// JustifiedCheckpoint -- passthrough.
+func (e Exporter) JustifiedCheckpoint(ctx context.Context) (*eth.Checkpoint, error) {
+	return e.db.JustifiedCheckpoint(ctx)
+}
+
+// FinalizedCheckpoint -- passthrough.
+func (e Exporter) FinalizedCheckpoint(ctx context.Context) (*eth.Checkpoint, error) {
+	return e.db.FinalizedCheckpoint(ctx)
+}
+
+// ArchivedActiveValidatorChanges -- passthrough.
+func (e Exporter) ArchivedActiveValidatorChanges(ctx context.Context, epoch uint64) (*ethereum_beacon_p2p_v1.ArchivedActiveSetChanges, error) {
+	return e.db.ArchivedActiveValidatorChanges(ctx, epoch)
+}
+
+// ArchivedCommitteeInfo -- passthrough.
+func (e Exporter) ArchivedCommitteeInfo(ctx context.Context, epoch uint64) (*ethereum_beacon_p2p_v1.ArchivedCommitteeInfo, error) {
+	return e.db.ArchivedCommitteeInfo(ctx, epoch)
+}
+
+// ArchivedBalances -- passthrough.
+func (e Exporter) ArchivedBalances(ctx context.Context, epoch uint64) ([]uint64, error) {
+	return e.db.ArchivedBalances(ctx, epoch)
+}
+
+// ArchivedValidatorParticipation -- passthrough.
+func (e Exporter) ArchivedValidatorParticipation(ctx context.Context, epoch uint64) (*eth.ValidatorParticipation, error) {
+	return e.db.ArchivedValidatorParticipation(ctx, epoch)
+}
+
+// DepositContractAddress -- passthrough.
+func (e Exporter) DepositContractAddress(ctx context.Context) ([]byte, error) {
+	return e.db.DepositContractAddress(ctx)
+}
+
+// SaveHeadBlockRoot -- passthrough.
+func (e Exporter) SaveHeadBlockRoot(ctx context.Context, blockRoot [32]byte) error {
+	return e.db.SaveHeadBlockRoot(ctx, blockRoot)
+}
+
+// SaveGenesisBlockRoot -- passthrough.
+func (e Exporter) SaveGenesisBlockRoot(ctx context.Context, blockRoot [32]byte) error {
+	return e.db.SaveGenesisBlockRoot(ctx, blockRoot)
+}
+
+// SaveValidatorIndex -- passthrough.
+func (e Exporter) SaveValidatorIndex(ctx context.Context, publicKey [48]byte, validatorIdx uint64) error {
+	return e.db.SaveValidatorIndex(ctx, publicKey, validatorIdx)
+}
+
+// SaveState -- passthrough.
+func (e Exporter) SaveState(ctx context.Context, state *ethereum_beacon_p2p_v1.BeaconState, blockRoot [32]byte) error {
+	return e.db.SaveState(ctx, state, blockRoot)
+}
+
+// SaveProposerSlashing -- passthrough.
+func (e Exporter) SaveProposerSlashing(ctx context.Context, slashing *eth.ProposerSlashing) error {
+	return e.db.SaveProposerSlashing(ctx, slashing)
+}
+
+// SaveAttesterSlashing -- passthrough.
+func (e Exporter) SaveAttesterSlashing(ctx context.Context, slashing *eth.AttesterSlashing) error {
+	return e.db.SaveAttesterSlashing(ctx, slashing)
+}
+
+// SaveVoluntaryExit -- passthrough.
+func (e Exporter) SaveVoluntaryExit(ctx context.Context, exit *eth.VoluntaryExit) error {
+	return e.db.SaveVoluntaryExit(ctx, exit)
+}
+
+// SaveJustifiedCheckpoint -- passthrough.
+func (e Exporter) SaveJustifiedCheckpoint(ctx context.Context, checkpoint *eth.Checkpoint) error {
+	return e.db.SaveJustifiedCheckpoint(ctx, checkpoint)
+}
+
+// SaveFinalizedCheckpoint -- passthrough.
+func (e Exporter) SaveFinalizedCheckpoint(ctx context.Context, checkpoint *eth.Checkpoint) error {
+	return e.db.SaveFinalizedCheckpoint(ctx, checkpoint)
+}
+
+// SaveArchivedActiveValidatorChanges -- passthrough.
+func (e Exporter) SaveArchivedActiveValidatorChanges(ctx context.Context, epoch uint64, changes *ethereum_beacon_p2p_v1.ArchivedActiveSetChanges) error {
+	return e.db.SaveArchivedActiveValidatorChanges(ctx, epoch, changes)
+}
+
+// SaveArchivedCommitteeInfo -- passthrough.
+func (e Exporter) SaveArchivedCommitteeInfo(ctx context.Context, epoch uint64, info *ethereum_beacon_p2p_v1.ArchivedCommitteeInfo) error {
+	return e.db.SaveArchivedCommitteeInfo(ctx, epoch, info)
+}
+
+// SaveArchivedBalances -- passthrough.
+func (e Exporter) SaveArchivedBalances(ctx context.Context, epoch uint64, balances []uint64) error {
+	return e.db.SaveArchivedBalances(ctx, epoch, balances)
+}
+
+// SaveArchivedValidatorParticipation -- passthrough.
+func (e Exporter) SaveArchivedValidatorParticipation(ctx context.Context, epoch uint64, part *eth.ValidatorParticipation) error {
+	return e.db.SaveArchivedValidatorParticipation(ctx, epoch, part)
+}
+
+// SaveDepositContractAddress -- passthrough.
+func (e Exporter) SaveDepositContractAddress(ctx context.Context, addr common.Address) error {
+	return e.db.SaveDepositContractAddress(ctx, addr)
+}
+
+// DeleteState -- passthrough.
+func (e Exporter) DeleteState(ctx context.Context, blockRoot [32]byte) error {
+	return e.db.DeleteState(ctx, blockRoot)
+}
+
+// DeleteStates -- passthrough.
+func (e Exporter) DeleteStates(ctx context.Context, blockRoots [][32]byte) error {
+	return e.db.DeleteStates(ctx, blockRoots)
+}
+
+// IsFinalizedBlock -- passthrough.
+func (e Exporter) IsFinalizedBlock(ctx context.Context, blockRoot [32]byte) bool {
+	return e.db.IsFinalizedBlock(ctx, blockRoot)
+}
--- a/beacon-chain/db/kv/BUILD.bazel
+++ b/beacon-chain/db/kv/BUILD.bazel
@ -26,6 +26,7 @@ go_library(
    deps = [
        "//beacon-chain/core/helpers:go_default_library",
        "//beacon-chain/db/filters:go_default_library",
+        "//beacon-chain/db/iface:go_default_library",
        "//proto/beacon/db:go_default_library",
        "//proto/beacon/p2p/v1:go_default_library",
        "//shared/bytesutil:go_default_library",
--- a/beacon-chain/db/kv/kv.go
+++ b/beacon-chain/db/kv/kv.go
@ -11,8 +11,11 @@ import (
 	"github.com/mdlayher/prombolt"
 	"github.com/pkg/errors"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prysmaticlabs/prysm/beacon-chain/db/iface"
 )

+var _ = iface.Database(&Store{})
+
 const (
 	// VotesCacheSize with 1M validators will be 8MB.
 	VotesCacheSize = 1 << 23
--- a/shared/featureconfig/config.go
+++ b/shared/featureconfig/config.go
@ -35,6 +35,7 @@ type Flags struct {
 	EnableSnappyDBCompression bool // EnableSnappyDBCompression in the database.
 	EnableCustomStateSSZ      bool   // EnableCustomStateSSZ in the the state transition function.
 	InitSyncCacheState        bool // InitSyncCacheState caches state during initial sync.
+	KafkaBootstrapServers    string // KafkaBootstrapServers to find kafka servers to stream blocks, attestations, etc.

 	// Cache toggles.
 	EnableAttestationCache   bool // EnableAttestationCache; see https://github.com/prysmaticlabs/prysm/issues/3106.
@ -122,6 +123,10 @@ func ConfigureBeaconChain(ctx *cli.Context) {
 		log.Warn("Enabled skip slots cache.")
 		cfg.EnableSkipSlotsCache = true
 	}
+	if ctx.GlobalString(kafkaBootstrapServersFlag.Name) != "" {
+		log.Warn("Enabling experimental kafka streaming.")
+		cfg.KafkaBootstrapServers = ctx.GlobalString(kafkaBootstrapServersFlag.Name)
+	}
 	if ctx.GlobalBool(enableCommitteeCacheFlag.Name) {
 		log.Warn("Enabled committee cache.")
 		cfg.EnableCommitteeCache = true
--- a/shared/featureconfig/flags.go
+++ b/shared/featureconfig/flags.go
@ -73,6 +73,10 @@ var (
 		Name:  "enable-skip-slots-cache",
 		Usage: "Enables the skip slot cache to be used in the event of skipped slots.",
 	}
+	kafkaBootstrapServersFlag = cli.StringFlag{
+		Name:  "kafka-url",
+		Usage: "Stream attestations and blocks to specified kafka servers. This field is used for bootstrap.servers kafka config field.",
+	}
 	enableSnappyDBCompressionFlag = cli.BoolFlag{
 		Name:  "snappy",
 		Usage: "Enables snappy compression in the database.",
@ -157,6 +161,7 @@ var BeaconChainFlags = append(deprecatedFlags, []cli.Flag{
 	initSyncCacheState,
 	NewCacheFlag,
 	SkipBLSVerifyFlag,
+	kafkaBootstrapServersFlag,
 	enableBackupWebhookFlag,
 	enableBLSPubkeyCacheFlag,
 	enableShuffledIndexCache,
--- a/third_party/in_gopkg_confluentinc_confluent_kafka_go_v1.patch
+++ b/third_party/in_gopkg_confluentinc_confluent_kafka_go_v1.patch
@ -0,0 +1,10 @@
+--- a/kafka/BUILD.bazel
+++ b/kafka/BUILD.bazel
+@@ -23,6 +23,7 @@
+         "producer.go",
+         "testhelpers.go",
+     ],
+    cdeps = ["@prysm//third_party/kafka:librdkafka"],
+     cgo = True,
+     importpath = "gopkg.in/confluentinc/confluent-kafka-go.v1/kafka",
+     visibility = ["//visibility:public"],
--- a/third_party/kafka/BUILD.bazel
+++ b/third_party/kafka/BUILD.bazel
@ -0,0 +1,20 @@
+load("@rules_foreign_cc//tools/build_defs:cmake.bzl", "cmake_external")
+
+cmake_external(
+    name = "librdkafka",
+    cache_entries = {
+        "RDKAFKA_BUILD_STATIC": "ON",
+        "WITH_ZSTD": "OFF",
+        "WITH_SSL": "OFF",
+        "WITH_SASL": "OFF",
+        "ENABLE_LZ4_EXT": "OFF",
+        "WITH_LIBDL": "OFF",
+        "WITH_ZLIB": "OFF",
+    },
+    lib_source = "@librdkafka//:all",
+    static_libraries = [
+        "librdkafka++.a",
+        "librdkafka.a",
+    ],
+    visibility = ["//visibility:public"],
+)