From 79e0674f4078a8e77daf161ef1879d8441775e40 Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 3 Apr 2020 09:27:18 -0700
Subject: [PATCH 01/18] Add client implementation

---
 validator/client/validator.go | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/validator/client/validator.go b/validator/client/validator.go
index 0e8b5e75b720..0d1174490f97 100644
--- a/validator/client/validator.go
+++ b/validator/client/validator.go
@@ -337,6 +337,13 @@ func (v *validator) RolesAt(ctx context.Context, slot uint64) (map[[48]byte][]pb
 				roles = append(roles, pb.ValidatorRole_AGGREGATOR)
 			}
 
+			if _, err := v.validatorClient.SubscribeCommitteeSubnet(ctx, &ethpb.CommitteeSubnetSubscribeRequest{
+				Slot:         slot,
+				CommitteeId:  duty.CommitteeIndex,
+				IsAggregator: aggregator,
+			}); err != nil {
+				return nil, err
+			}
 		}
 		if len(roles) == 0 {
 			roles = append(roles, pb.ValidatorRole_UNKNOWN)

From 17b771b901bac288db6d18b9749426422959021d Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 3 Apr 2020 09:27:44 -0700
Subject: [PATCH 02/18] Update workspace

---
 WORKSPACE | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/WORKSPACE b/WORKSPACE
index fe391cf7900b..23fe21149443 100644
--- a/WORKSPACE
+++ b/WORKSPACE
@@ -1309,7 +1309,7 @@ go_repository(
 
 go_repository(
     name = "com_github_prysmaticlabs_ethereumapis",
-    commit = "90224d88dd65813ba2f35197bb1bb8915b2d0c6b",
+    commit = "3f6a75ac9460621b140270b90057a5a445d66436",
     importpath = "github.com/prysmaticlabs/ethereumapis",
     patch_args = ["-p1"],
     patches = [

From d7cf6901fefa8bfb77fa35f1248a069ec10c5e81 Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 3 Apr 2020 09:27:57 -0700
Subject: [PATCH 03/18] Update server

---
 beacon-chain/cache/committee_ids.go           | 22 ++++++++++--------
 beacon-chain/rpc/validator/assignments.go     |  7 ------
 beacon-chain/rpc/validator/attester.go        | 23 +++++++++----------
 .../sync/initial-sync/blocks_fetcher.go       | 11 ++++-----
 4 files changed, 29 insertions(+), 34 deletions(-)

diff --git a/beacon-chain/cache/committee_ids.go b/beacon-chain/cache/committee_ids.go
index 85672884f166..fa054508556c 100644
--- a/beacon-chain/cache/committee_ids.go
+++ b/beacon-chain/cache/committee_ids.go
@@ -4,6 +4,7 @@ import (
 	"sync"
 
 	lru "github.com/hashicorp/golang-lru"
+	"github.com/prysmaticlabs/prysm/shared/params"
 	"github.com/prysmaticlabs/prysm/shared/sliceutil"
 )
 
@@ -16,27 +17,30 @@ type committeeIDs struct {
 var CommitteeIDs = newCommitteeIDs()
 
 func newCommitteeIDs() *committeeIDs {
-	cache, err := lru.New(8)
+	maxCommitteesPerEpoch := int(params.BeaconConfig().MaxCommitteesPerSlot * params.BeaconConfig().SlotsPerEpoch)
+	cache, err := lru.New(maxCommitteesPerEpoch)
 	if err != nil {
 		panic(err)
 	}
 	return &committeeIDs{cache: cache}
 }
 
-// AddIDs to the cache for attestation committees by epoch.
-func (t *committeeIDs) AddIDs(indices []uint64, epoch uint64) {
+// AddID adds committee ID for subscribing subnet for the attester and/or aggregator of a given slot.
+func (t *committeeIDs) AddID(committeeID uint64, slot uint64) {
 	t.lock.Lock()
 	defer t.lock.Unlock()
-	val, exists := t.cache.Get(epoch)
+
+	committeeIDs := []uint64{committeeID}
+	val, exists := t.cache.Get(slot)
 	if exists {
-		indices = sliceutil.UnionUint64(append(indices, val.([]uint64)...))
+		committeeIDs = sliceutil.UnionUint64(append(val.([]uint64), committeeIDs...))
 	}
-	t.cache.Add(epoch, indices)
+	t.cache.Add(slot, committeeIDs)
 }
 
-// GetIDs from the cache for attestation committees by epoch.
-func (t *committeeIDs) GetIDs(epoch uint64) []uint64 {
-	val, exists := t.cache.Get(epoch)
+// GetIDs gets the committee ID for subscribing subnet for attester and/or aggregator of the slot.
+func (t *committeeIDs) GetIDs(slot uint64) []uint64 {
+	val, exists := t.cache.Get(slot)
 	if !exists {
 		return []uint64{}
 	}
diff --git a/beacon-chain/rpc/validator/assignments.go b/beacon-chain/rpc/validator/assignments.go
index c282e1e3cb0c..ceca4f6b28f7 100644
--- a/beacon-chain/rpc/validator/assignments.go
+++ b/beacon-chain/rpc/validator/assignments.go
@@ -4,10 +4,8 @@ import (
 	"context"
 
 	ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
-	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
 	"github.com/prysmaticlabs/prysm/beacon-chain/core/state"
-	"github.com/prysmaticlabs/prysm/shared/featureconfig"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 )
@@ -87,11 +85,6 @@ func (vs *Server) GetDuties(ctx context.Context, req *ethpb.DutiesRequest) (*eth
 
 	}
 
-	if featureconfig.Get().EnableDynamicCommitteeSubnets {
-		cache.CommitteeIDs.AddIDs(committeeIDs, req.Epoch)
-		cache.CommitteeIDs.AddIDs(nextCommitteeIDs, req.Epoch+1)
-	}
-
 	return &ethpb.DutiesResponse{
 		Duties: validatorAssignments,
 	}, nil
diff --git a/beacon-chain/rpc/validator/attester.go b/beacon-chain/rpc/validator/attester.go
index f813ad395bd1..15f0b8bce442 100644
--- a/beacon-chain/rpc/validator/attester.go
+++ b/beacon-chain/rpc/validator/attester.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"time"
 
+	ptypes "github.com/gogo/protobuf/types"
 	ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
 	"github.com/prysmaticlabs/go-ssz"
 	"github.com/prysmaticlabs/prysm/beacon-chain/cache"
@@ -36,12 +37,6 @@ func (vs *Server) GetAttestationData(ctx context.Context, req *ethpb.Attestation
 		trace.Int64Attribute("committeeIndex", int64(req.CommitteeIndex)),
 	)
 
-	// If attestation committee subnets are enabled, we track the committee
-	// index into a cache.
-	if featureconfig.Get().EnableDynamicCommitteeSubnets {
-		cache.CommitteeIDs.AddIDs([]uint64{req.CommitteeIndex}, helpers.SlotToEpoch(req.Slot))
-	}
-
 	if vs.SyncChecker.Syncing() {
 		return nil, status.Errorf(codes.Unavailable, "Syncing to latest head, not ready to respond")
 	}
@@ -159,12 +154,6 @@ func (vs *Server) ProposeAttestation(ctx context.Context, att *ethpb.Attestation
 		return nil, status.Error(codes.InvalidArgument, "Incorrect attestation signature")
 	}
 
-	// If attestation committee subnets are enabled, we track the committee
-	// index into a cache.
-	if featureconfig.Get().EnableDynamicCommitteeSubnets {
-		cache.CommitteeIDs.AddIDs([]uint64{att.Data.CommitteeIndex}, helpers.SlotToEpoch(att.Data.Slot))
-	}
-
 	root, err := ssz.HashTreeRoot(att.Data)
 	if err != nil {
 		return nil, status.Errorf(codes.Internal, "Could not tree hash attestation: %v", err)
@@ -235,3 +224,13 @@ func (vs *Server) waitToOneThird(ctx context.Context, slot uint64) {
 		}
 	}
 }
+
+// SubscribeCommitteeSubnet subscribes to the committee ID subnet given subscribe request.
+func (vs *Server) SubscribeCommitteeSubnet(ctx context.Context, req *ethpb.CommitteeSubnetSubscribeRequest) (*ptypes.Empty, error) {
+	if req.IsAggregator {
+		cache.CommitteeIDs.AddID(req.CommitteeId, req.Slot)
+	} else {
+		// What should we do here as an attester?
+	}
+	return &ptypes.Empty{}, nil
+}
diff --git a/beacon-chain/sync/initial-sync/blocks_fetcher.go b/beacon-chain/sync/initial-sync/blocks_fetcher.go
index 752fc6ce921f..c373bc62fc5b 100644
--- a/beacon-chain/sync/initial-sync/blocks_fetcher.go
+++ b/beacon-chain/sync/initial-sync/blocks_fetcher.go
@@ -82,7 +82,7 @@ func newBlocksFetcher(ctx context.Context, cfg *blocksFetcherConfig) *blocksFetc
 	rateLimiter := leakybucket.NewCollector(
 		allowedBlocksPerSecond, /* rate */
 		allowedBlocksPerSecond, /* capacity */
-		false                   /* deleteEmptyBuckets */)
+		false /* deleteEmptyBuckets */)
 
 	return &blocksFetcher{
 		ctx:            ctx,
@@ -466,7 +466,7 @@ func (f *blocksFetcher) selectPeers(peers []peer.ID) []peer.ID {
 // nonSkippedSlotAfter checks slots after the given one in an attempt to find non-empty future slot.
 func (f *blocksFetcher) nonSkippedSlotAfter(ctx context.Context, slot uint64) (uint64, error) {
 	headEpoch := helpers.SlotToEpoch(f.headFetcher.HeadSlot())
-	root, epoch, peers := f.p2p.Peers().BestFinalized(params.BeaconConfig().MaxPeersToSync, headEpoch)
+	_, epoch, peers := f.p2p.Peers().BestFinalized(params.BeaconConfig().MaxPeersToSync, headEpoch)
 	if len(peers) == 0 {
 		return 0, errNoPeersAvailable
 	}
@@ -481,10 +481,9 @@ func (f *blocksFetcher) nonSkippedSlotAfter(ctx context.Context, slot uint64) (u
 
 	for slot <= helpers.StartSlot(epoch+1) {
 		req := &p2ppb.BeaconBlocksByRangeRequest{
-			HeadBlockRoot: root,
-			StartSlot:     slot + 1,
-			Count:         blockBatchSize,
-			Step:          1,
+			StartSlot: slot + 1,
+			Count:     blockBatchSize,
+			Step:      1,
 		}
 
 		blocks, err := f.requestBlocks(ctx, req, nextPID())

From d7615ea99e30075cf7af18fa572fdbc2ca7c0abd Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 3 Apr 2020 09:35:39 -0700
Subject: [PATCH 04/18] Update service

---
 .../beacon_node_validator_service_mock.go     | 22 +++++++++++++++++++
 1 file changed, 22 insertions(+)

diff --git a/validator/internal/beacon_node_validator_service_mock.go b/validator/internal/beacon_node_validator_service_mock.go
index 554384c440dd..28b3cfe8c053 100644
--- a/validator/internal/beacon_node_validator_service_mock.go
+++ b/validator/internal/beacon_node_validator_service_mock.go
@@ -10,7 +10,9 @@ import (
 
 	ptypes "github.com/gogo/protobuf/types"
 	gomock "github.com/golang/mock/gomock"
+	eth "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
 	ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
+	"github.com/prysmaticlabs/prysm/bazel-prysm/external/com_github_golang_protobuf/ptypes/empty"
 	grpc "google.golang.org/grpc"
 	metadata "google.golang.org/grpc/metadata"
 )
@@ -967,3 +969,23 @@ func (mr *MockBeaconNodeValidator_WaitForChainStartServerMockRecorder) RecvMsg(m
 	mr.mock.ctrl.T.Helper()
 	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "RecvMsg", reflect.TypeOf((*MockBeaconNodeValidator_WaitForChainStartServer)(nil).RecvMsg), m)
 }
+
+// SubscribeCommitteeSubnet mocks base method
+func (m *MockBeaconNodeValidatorClient) SubscribeCommitteeSubnet(arg0 context.Context, arg1 *eth.CommitteeSubnetSubscribeRequest, arg2 ...grpc.CallOption) (*empty.Empty, error) {
+	m.ctrl.T.Helper()
+	varargs := []interface{}{arg0, arg1}
+	for _, a := range arg2 {
+		varargs = append(varargs, a)
+	}
+	ret := m.ctrl.Call(m, "SubscribeCommitteeSubnet", varargs...)
+	ret0, _ := ret[0].(*empty.Empty)
+	ret1, _ := ret[1].(error)
+	return ret0, ret1
+}
+
+// SubscribeCommitteeSubnet indicates an expected call of SubscribeCommitteeSubnet
+func (mr *MockBeaconNodeValidatorClientMockRecorder) SubscribeCommitteeSubnet(arg0, arg1 interface{}, arg2 ...interface{}) *gomock.Call {
+	mr.mock.ctrl.T.Helper()
+	varargs := append([]interface{}{arg0, arg1}, arg2...)
+	return mr.mock.ctrl.RecordCallWithMethodType(mr.mock, "SubscribeCommitteeSubnet", reflect.TypeOf((*MockBeaconNodeValidatorClient)(nil).SubscribeCommitteeSubnet), varargs...)
+}

From 10ca5c8eda72335299c35aa815dca1e6134dadce Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 3 Apr 2020 09:38:22 -0700
Subject: [PATCH 05/18] Gaz

---
 ...thub_prysmaticlabs_ethereumapis-tags.patch | 22 ++++++++++---------
 validator/internal/BUILD.bazel                |  1 +
 2 files changed, 13 insertions(+), 10 deletions(-)

diff --git a/third_party/com_github_prysmaticlabs_ethereumapis-tags.patch b/third_party/com_github_prysmaticlabs_ethereumapis-tags.patch
index 854a3fd74082..47c06b1940ed 100644
--- a/third_party/com_github_prysmaticlabs_ethereumapis-tags.patch
+++ b/third_party/com_github_prysmaticlabs_ethereumapis-tags.patch
@@ -447,7 +447,7 @@ index 8ee263b..60607de 100644
  
      // The epoch for which this set of validator assignments is valid.
 diff --git a/eth/v1alpha1/validator.proto b/eth/v1alpha1/validator.proto
-index 068a04c..80f73b8 100644
+index 3455de7..f4fab59 100644
 --- a/eth/v1alpha1/validator.proto
 +++ b/eth/v1alpha1/validator.proto
 @@ -15,6 +15,7 @@ syntax = "proto3";
@@ -458,7 +458,7 @@ index 068a04c..80f73b8 100644
  import "google/api/annotations.proto";
  import "google/protobuf/empty.proto";
  import "eth/v1alpha1/beacon_block.proto";
-@@ -197,7 +198,7 @@ message DomainResponse {
+@@ -208,7 +209,7 @@ message DomainResponse {
  
  message ValidatorActivationRequest {
      // A list of 48 byte validator public keys.
@@ -467,7 +467,7 @@ index 068a04c..80f73b8 100644
  }
  
  message ValidatorActivationResponse {
-@@ -223,7 +224,7 @@ message ChainStartResponse {
+@@ -234,7 +235,7 @@ message ChainStartResponse {
  
  message ValidatorIndexRequest {
      // A 48 byte validator public key.
@@ -476,7 +476,7 @@ index 068a04c..80f73b8 100644
  }
  
  message ValidatorIndexResponse {
-@@ -233,7 +234,7 @@ message ValidatorIndexResponse {
+@@ -244,7 +245,7 @@ message ValidatorIndexResponse {
  
  message ValidatorStatusRequest {
      // A 48 byte validator public key.
@@ -485,7 +485,7 @@ index 068a04c..80f73b8 100644
  }
  
  enum ValidatorStatus {
-@@ -271,7 +272,7 @@ message DutiesRequest {
+@@ -282,7 +283,7 @@ message DutiesRequest {
      uint64 epoch = 1;
  
      // Array of byte encoded BLS public keys.
@@ -494,7 +494,7 @@ index 068a04c..80f73b8 100644
  }
  
  message DutiesResponse {
-@@ -290,7 +291,7 @@ message DutiesResponse {
+@@ -301,7 +302,7 @@ message DutiesResponse {
          uint64 proposer_slot = 4;
  
          // 48 byte BLS public key for the validator who's assigned to perform a duty.
@@ -503,7 +503,7 @@ index 068a04c..80f73b8 100644
  
          // The current status of the validator assigned to perform the duty.
          ValidatorStatus status = 6;
-@@ -305,15 +306,16 @@ message BlockRequest {
+@@ -316,15 +317,16 @@ message BlockRequest {
      uint64 slot = 1;
  
      // Validator's 32 byte randao reveal secret of the current epoch.
@@ -523,7 +523,7 @@ index 068a04c..80f73b8 100644
  }
  
  message AttestationDataRequest {
-@@ -326,7 +328,7 @@ message AttestationDataRequest {
+@@ -337,7 +339,7 @@ message AttestationDataRequest {
  
  message AttestResponse {
      // The root of the attestation data successfully submitted to the beacon node.
@@ -532,7 +532,7 @@ index 068a04c..80f73b8 100644
  }
  
  message AggregateSelectionRequest {
-@@ -335,10 +337,10 @@ message AggregateSelectionRequest {
+@@ -346,10 +348,10 @@ message AggregateSelectionRequest {
      // Committee index of the validator at the given slot.
      uint64 committee_index = 2;
      // 48 byte public key of the validator.
@@ -545,7 +545,7 @@ index 068a04c..80f73b8 100644
  }
  
  message AggregateSelectionResponse {
-@@ -353,16 +355,16 @@ message SignedAggregateSubmitRequest {
+@@ -364,7 +366,7 @@ message SignedAggregateSubmitRequest {
  
  message SignedAggregateSubmitResponse {
      // The 32 byte hash tree root of the aggregated attestation data.
@@ -553,6 +553,8 @@ index 068a04c..80f73b8 100644
 +    bytes attestation_data_root = 1  [(gogoproto.moretags) = "ssz-size:\"32\""];
  }
  
+ message CommitteeSubnetSubscribeRequest {
+@@ -381,10 +383,10 @@ message CommitteeSubnetSubscribeRequest {
  // An Ethereum 2.0 validator.
  message Validator {
      // 48 byte BLS public key used for the validator's activities.
diff --git a/validator/internal/BUILD.bazel b/validator/internal/BUILD.bazel
index 52ab303ee136..452656cb98b1 100644
--- a/validator/internal/BUILD.bazel
+++ b/validator/internal/BUILD.bazel
@@ -13,6 +13,7 @@ go_library(
         "@com_github_gogo_protobuf//types:go_default_library",
         "@com_github_golang_mock//gomock:go_default_library",
         "@com_github_prysmaticlabs_ethereumapis//eth/v1alpha1:go_default_library",
+        "@com_github_prysmaticlabs_prysm//bazel-prysm/external/com_github_golang_protobuf/ptypes/empty:go_default_library",
         "@org_golang_google_grpc//:go_default_library",
         "@org_golang_google_grpc//metadata:go_default_library",
     ],

From 5950ab6a9bd4fd9970ff81fcf73a9af553e40bd0 Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 3 Apr 2020 09:55:58 -0700
Subject: [PATCH 06/18] Mocks

---
 validator/internal/BUILD.bazel                           | 1 -
 validator/internal/beacon_node_validator_service_mock.go | 5 ++---
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/validator/internal/BUILD.bazel b/validator/internal/BUILD.bazel
index 452656cb98b1..52ab303ee136 100644
--- a/validator/internal/BUILD.bazel
+++ b/validator/internal/BUILD.bazel
@@ -13,7 +13,6 @@ go_library(
         "@com_github_gogo_protobuf//types:go_default_library",
         "@com_github_golang_mock//gomock:go_default_library",
         "@com_github_prysmaticlabs_ethereumapis//eth/v1alpha1:go_default_library",
-        "@com_github_prysmaticlabs_prysm//bazel-prysm/external/com_github_golang_protobuf/ptypes/empty:go_default_library",
         "@org_golang_google_grpc//:go_default_library",
         "@org_golang_google_grpc//metadata:go_default_library",
     ],
diff --git a/validator/internal/beacon_node_validator_service_mock.go b/validator/internal/beacon_node_validator_service_mock.go
index 28b3cfe8c053..1be712ad60a4 100644
--- a/validator/internal/beacon_node_validator_service_mock.go
+++ b/validator/internal/beacon_node_validator_service_mock.go
@@ -12,7 +12,6 @@ import (
 	gomock "github.com/golang/mock/gomock"
 	eth "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
 	ethpb "github.com/prysmaticlabs/ethereumapis/eth/v1alpha1"
-	"github.com/prysmaticlabs/prysm/bazel-prysm/external/com_github_golang_protobuf/ptypes/empty"
 	grpc "google.golang.org/grpc"
 	metadata "google.golang.org/grpc/metadata"
 )
@@ -971,14 +970,14 @@ func (mr *MockBeaconNodeValidator_WaitForChainStartServerMockRecorder) RecvMsg(m
 }
 
 // SubscribeCommitteeSubnet mocks base method
-func (m *MockBeaconNodeValidatorClient) SubscribeCommitteeSubnet(arg0 context.Context, arg1 *eth.CommitteeSubnetSubscribeRequest, arg2 ...grpc.CallOption) (*empty.Empty, error) {
+func (m *MockBeaconNodeValidatorClient) SubscribeCommitteeSubnet(arg0 context.Context, arg1 *eth.CommitteeSubnetSubscribeRequest, arg2 ...grpc.CallOption) (*ptypes.Empty, error) {
 	m.ctrl.T.Helper()
 	varargs := []interface{}{arg0, arg1}
 	for _, a := range arg2 {
 		varargs = append(varargs, a)
 	}
 	ret := m.ctrl.Call(m, "SubscribeCommitteeSubnet", varargs...)
-	ret0, _ := ret[0].(*empty.Empty)
+	ret0, _ := ret[0].(*ptypes.Empty)
 	ret1, _ := ret[1].(error)
 	return ret0, ret1
 }

From cd7a23627d2dddda8712e7802063d22063a61671 Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 3 Apr 2020 10:07:21 -0700
Subject: [PATCH 07/18] Fixed validator tests

---
 validator/client/validator_test.go | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/validator/client/validator_test.go b/validator/client/validator_test.go
index 81f4a290416b..dae939574cd2 100644
--- a/validator/client/validator_test.go
+++ b/validator/client/validator_test.go
@@ -604,11 +604,22 @@ func TestRolesAt_OK(t *testing.T) {
 		gomock.Any(), // ctx
 		gomock.Any(), // epoch
 	).Return(&ethpb.DomainResponse{}, nil /*err*/)
+
 	m.validatorClient.EXPECT().DomainData(
 		gomock.Any(), // ctx
 		gomock.Any(), // epoch
 	).Return(&ethpb.DomainResponse{}, nil /*err*/)
 
+	m.validatorClient.EXPECT().SubscribeCommitteeSubnet(
+		gomock.Any(), // ctx
+		gomock.Any(), // epoch
+	).Return(nil, nil /*err*/)
+
+	m.validatorClient.EXPECT().SubscribeCommitteeSubnet(
+		gomock.Any(), // ctx
+		gomock.Any(), // epoch
+	).Return(nil, nil /*err*/)
+
 	roleMap, err := v.RolesAt(context.Background(), 1)
 	if err != nil {
 		t.Fatal(err)
@@ -671,6 +682,11 @@ func TestRolesAt_DoesNotAssignProposer_Slot0(t *testing.T) {
 		gomock.Any(), // epoch
 	).Return(&ethpb.DomainResponse{}, nil /*err*/)
 
+	m.validatorClient.EXPECT().SubscribeCommitteeSubnet(
+		gomock.Any(), // ctx
+		gomock.Any(), // epoch
+	).Return(nil, nil /*err*/)
+
 	roleMap, err := v.RolesAt(context.Background(), 0)
 	if err != nil {
 		t.Fatal(err)

From d8f76901c3d25222a99fefd4f97bfa794bbe56fb Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 3 Apr 2020 10:16:00 -0700
Subject: [PATCH 08/18] Add round tirp tests

---
 beacon-chain/cache/BUILD.bazel           |  1 +
 beacon-chain/cache/committee_ids.go      |  2 +-
 beacon-chain/cache/committee_ids_test.go | 33 ++++++++++++++++++++++++
 beacon-chain/rpc/validator/attester.go   |  4 +--
 4 files changed, 37 insertions(+), 3 deletions(-)
 create mode 100644 beacon-chain/cache/committee_ids_test.go

diff --git a/beacon-chain/cache/BUILD.bazel b/beacon-chain/cache/BUILD.bazel
index 9b508498b301..87454c83b8c5 100644
--- a/beacon-chain/cache/BUILD.bazel
+++ b/beacon-chain/cache/BUILD.bazel
@@ -41,6 +41,7 @@ go_test(
         "attestation_data_test.go",
         "checkpoint_state_test.go",
         "committee_fuzz_test.go",
+        "committee_ids_test.go",
         "committee_test.go",
         "eth1_data_test.go",
         "feature_flag_test.go",
diff --git a/beacon-chain/cache/committee_ids.go b/beacon-chain/cache/committee_ids.go
index fa054508556c..5277247b0f63 100644
--- a/beacon-chain/cache/committee_ids.go
+++ b/beacon-chain/cache/committee_ids.go
@@ -26,7 +26,7 @@ func newCommitteeIDs() *committeeIDs {
 }
 
 // AddID adds committee ID for subscribing subnet for the attester and/or aggregator of a given slot.
-func (t *committeeIDs) AddID(committeeID uint64, slot uint64) {
+func (t *committeeIDs) AddID(slot uint64, committeeID uint64) {
 	t.lock.Lock()
 	defer t.lock.Unlock()
 
diff --git a/beacon-chain/cache/committee_ids_test.go b/beacon-chain/cache/committee_ids_test.go
new file mode 100644
index 000000000000..9d47da162761
--- /dev/null
+++ b/beacon-chain/cache/committee_ids_test.go
@@ -0,0 +1,33 @@
+package cache
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestCommitteeIDCache_RoundTrip(t *testing.T) {
+	c := newCommitteeIDs()
+	slot := uint64(100)
+	committeeIDs := c.GetIDs(slot)
+	if len(committeeIDs) != 0 {
+		t.Errorf("Empty cache returned an object: %v", committeeIDs)
+	}
+
+	c.AddID(slot, 1)
+	res := c.GetIDs(slot)
+	if !reflect.DeepEqual(res, []uint64{1}) {
+		t.Error("Expected equal value to return from cache")
+	}
+
+	c.AddID(slot, 2)
+	res = c.GetIDs(slot)
+	if !reflect.DeepEqual(res, []uint64{1, 2}) {
+		t.Error("Expected equal value to return from cache")
+	}
+
+	c.AddID(slot, 3)
+	res = c.GetIDs(slot)
+	if !reflect.DeepEqual(res, []uint64{1, 2, 3}) {
+		t.Error("Expected equal value to return from cache")
+	}
+}
diff --git a/beacon-chain/rpc/validator/attester.go b/beacon-chain/rpc/validator/attester.go
index 15f0b8bce442..5bf432fd6590 100644
--- a/beacon-chain/rpc/validator/attester.go
+++ b/beacon-chain/rpc/validator/attester.go
@@ -228,9 +228,9 @@ func (vs *Server) waitToOneThird(ctx context.Context, slot uint64) {
 // SubscribeCommitteeSubnet subscribes to the committee ID subnet given subscribe request.
 func (vs *Server) SubscribeCommitteeSubnet(ctx context.Context, req *ethpb.CommitteeSubnetSubscribeRequest) (*ptypes.Empty, error) {
 	if req.IsAggregator {
-		cache.CommitteeIDs.AddID(req.CommitteeId, req.Slot)
+		cache.CommitteeIDs.AddID(req.Slot, req.CommitteeId)
 	} else {
-		// What should we do here as an attester?
+		// What should be done for an attester?
 	}
 	return &ptypes.Empty{}, nil
 }

From 5a996dbf0bea06e4c19050c3da6169cb9b083464 Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 3 Apr 2020 10:31:40 -0700
Subject: [PATCH 09/18] Fixed subnet test

---
 beacon-chain/p2p/subnets_test.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/beacon-chain/p2p/subnets_test.go b/beacon-chain/p2p/subnets_test.go
index a8a34270c0dd..9ab6e17d365b 100644
--- a/beacon-chain/p2p/subnets_test.go
+++ b/beacon-chain/p2p/subnets_test.go
@@ -109,7 +109,7 @@ func TestStartDiscV5_DiscoverPeersWithSubnets(t *testing.T) {
 
 	// Update ENR of a peer.
 	testService := &Service{dv5Listener: listeners[0]}
-	cache.CommitteeIDs.AddIDs([]uint64{10}, 0)
+	cache.CommitteeIDs.AddID(0, 10)
 	testService.RefreshENR(0)
 	time.Sleep(2 * time.Second)
 

From e9d1ee1d10861907f5d2dd55d42f36721e275576 Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 3 Apr 2020 15:25:41 -0700
Subject: [PATCH 10/18] Comment

---
 beacon-chain/rpc/validator/attester.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/beacon-chain/rpc/validator/attester.go b/beacon-chain/rpc/validator/attester.go
index 38134d4d61e9..42b862f3f855 100644
--- a/beacon-chain/rpc/validator/attester.go
+++ b/beacon-chain/rpc/validator/attester.go
@@ -228,9 +228,9 @@ func (vs *Server) waitToOneThird(ctx context.Context, slot uint64) {
 // SubscribeCommitteeSubnet subscribes to the committee ID subnet given subscribe request.
 func (vs *Server) SubscribeCommitteeSubnet(ctx context.Context, req *ethpb.CommitteeSubnetSubscribeRequest) (*ptypes.Empty, error) {
 	if req.IsAggregator {
-		cache.CommitteeIDs.AddID(req.Slot, req.CommitteeId)
+		// What should a node cache for an aggregator?
 	} else {
-		// What should be done for an attester?
+		cache.CommitteeIDs.AddID(req.Slot, req.CommitteeId)
 	}
 	return &ptypes.Empty{}, nil
 }

From de6b1ce5361440198ff77f4d25b4488a55d57583 Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 3 Apr 2020 21:47:36 -0700
Subject: [PATCH 11/18] Update committee cache

---
 beacon-chain/cache/committee_ids.go      | 66 ++++++++++++++++++------
 beacon-chain/cache/committee_ids_test.go | 37 ++++++++++---
 2 files changed, 80 insertions(+), 23 deletions(-)

diff --git a/beacon-chain/cache/committee_ids.go b/beacon-chain/cache/committee_ids.go
index 5277247b0f63..bdde07c7295f 100644
--- a/beacon-chain/cache/committee_ids.go
+++ b/beacon-chain/cache/committee_ids.go
@@ -9,38 +9,72 @@ import (
 )
 
 type committeeIDs struct {
-	cache *lru.Cache
-	lock  sync.RWMutex
+	attester       *lru.Cache
+	attesterLock   sync.RWMutex
+	aggregator     *lru.Cache
+	aggregatorLock sync.RWMutex
 }
 
-// CommitteeIDs for attestations.
+// CommitteeIDs for attester and aggregator.
 var CommitteeIDs = newCommitteeIDs()
 
 func newCommitteeIDs() *committeeIDs {
 	maxCommitteesPerEpoch := int(params.BeaconConfig().MaxCommitteesPerSlot * params.BeaconConfig().SlotsPerEpoch)
-	cache, err := lru.New(maxCommitteesPerEpoch)
+	attesterCache, err := lru.New(maxCommitteesPerEpoch)
 	if err != nil {
 		panic(err)
 	}
-	return &committeeIDs{cache: cache}
+	aggregatorCache, err := lru.New(maxCommitteesPerEpoch)
+	if err != nil {
+		panic(err)
+	}
+	return &committeeIDs{attester: attesterCache, aggregator: aggregatorCache}
+}
+
+// AddAttesterCommiteeID adds committee ID for subscribing subnet for the attester of a given slot.
+func (c *committeeIDs) AddAttesterCommiteeID(slot uint64, committeeID uint64) {
+	c.attesterLock.Lock()
+	defer c.attesterLock.Unlock()
+
+	ids := []uint64{committeeID}
+	val, exists := c.attester.Get(slot)
+	if exists {
+		ids = sliceutil.UnionUint64(append(val.([]uint64), ids...))
+	}
+	c.attester.Add(slot, ids)
 }
 
-// AddID adds committee ID for subscribing subnet for the attester and/or aggregator of a given slot.
-func (t *committeeIDs) AddID(slot uint64, committeeID uint64) {
-	t.lock.Lock()
-	defer t.lock.Unlock()
+// GetAttesterCommitteeIDs gets the committee ID for subscribing subnet for attester of the slot.
+func (c *committeeIDs) GetAttesterCommitteeIDs(slot uint64) []uint64 {
+	c.attesterLock.Lock()
+	defer c.attesterLock.Unlock()
 
-	committeeIDs := []uint64{committeeID}
-	val, exists := t.cache.Get(slot)
+	val, exists := c.attester.Get(slot)
+	if !exists {
+		return []uint64{}
+	}
+	return val.([]uint64)
+}
+
+// AddAggregatorCommiteeID adds committee ID for subscribing subnet for the aggregator of a given slot.
+func (c *committeeIDs) AddAggregatorCommiteeID(slot uint64, committeeID uint64) {
+	c.aggregatorLock.Lock()
+	defer c.aggregatorLock.Unlock()
+
+	ids := []uint64{committeeID}
+	val, exists := c.aggregator.Get(slot)
 	if exists {
-		committeeIDs = sliceutil.UnionUint64(append(val.([]uint64), committeeIDs...))
+		ids = sliceutil.UnionUint64(append(val.([]uint64), ids...))
 	}
-	t.cache.Add(slot, committeeIDs)
+	c.aggregator.Add(slot, ids)
 }
 
-// GetIDs gets the committee ID for subscribing subnet for attester and/or aggregator of the slot.
-func (t *committeeIDs) GetIDs(slot uint64) []uint64 {
-	val, exists := t.cache.Get(slot)
+// GetAggregatorCommitteeIDs gets the committee ID for subscribing subnet for aggregator of the slot.
+func (c *committeeIDs) GetAggregatorCommitteeIDs(slot uint64) []uint64 {
+	c.aggregatorLock.Lock()
+	defer c.aggregatorLock.Unlock()
+
+	val, exists := c.aggregator.Get(slot)
 	if !exists {
 		return []uint64{}
 	}
diff --git a/beacon-chain/cache/committee_ids_test.go b/beacon-chain/cache/committee_ids_test.go
index 9d47da162761..3ae97533a825 100644
--- a/beacon-chain/cache/committee_ids_test.go
+++ b/beacon-chain/cache/committee_ids_test.go
@@ -8,26 +8,49 @@ import (
 func TestCommitteeIDCache_RoundTrip(t *testing.T) {
 	c := newCommitteeIDs()
 	slot := uint64(100)
-	committeeIDs := c.GetIDs(slot)
+	committeeIDs := c.GetAggregatorCommitteeIDs(slot)
 	if len(committeeIDs) != 0 {
 		t.Errorf("Empty cache returned an object: %v", committeeIDs)
 	}
 
-	c.AddID(slot, 1)
-	res := c.GetIDs(slot)
+	c.AddAggregatorCommiteeID(slot, 1)
+	res := c.GetAggregatorCommitteeIDs(slot)
 	if !reflect.DeepEqual(res, []uint64{1}) {
 		t.Error("Expected equal value to return from cache")
 	}
 
-	c.AddID(slot, 2)
-	res = c.GetIDs(slot)
+	c.AddAggregatorCommiteeID(slot, 2)
+	res = c.GetAggregatorCommitteeIDs(slot)
 	if !reflect.DeepEqual(res, []uint64{1, 2}) {
 		t.Error("Expected equal value to return from cache")
 	}
 
-	c.AddID(slot, 3)
-	res = c.GetIDs(slot)
+	c.AddAggregatorCommiteeID(slot, 3)
+	res = c.GetAggregatorCommitteeIDs(slot)
 	if !reflect.DeepEqual(res, []uint64{1, 2, 3}) {
 		t.Error("Expected equal value to return from cache")
 	}
+
+	committeeIDs = c.GetAttesterCommitteeIDs(slot)
+	if len(committeeIDs) != 0 {
+		t.Errorf("Empty cache returned an object: %v", committeeIDs)
+	}
+
+	c.AddAttesterCommiteeID(slot, 11)
+	res = c.GetAttesterCommitteeIDs(slot)
+	if !reflect.DeepEqual(res, []uint64{11}) {
+		t.Error("Expected equal value to return from cache")
+	}
+
+	c.AddAttesterCommiteeID(slot, 22)
+	res = c.GetAttesterCommitteeIDs(slot)
+	if !reflect.DeepEqual(res, []uint64{11, 22}) {
+		t.Error("Expected equal value to return from cache")
+	}
+
+	c.AddAttesterCommiteeID(slot, 33)
+	res = c.GetAttesterCommitteeIDs(slot)
+	if !reflect.DeepEqual(res, []uint64{11, 22, 33}) {
+		t.Error("Expected equal value to return from cache")
+	}
 }

From 38f9b68ce9213498d01b6c6aa26b237768224e16 Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 3 Apr 2020 21:49:06 -0700
Subject: [PATCH 12/18] Comment

---
 beacon-chain/cache/committee_ids.go | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/beacon-chain/cache/committee_ids.go b/beacon-chain/cache/committee_ids.go
index bdde07c7295f..447f600817c8 100644
--- a/beacon-chain/cache/committee_ids.go
+++ b/beacon-chain/cache/committee_ids.go
@@ -19,12 +19,14 @@ type committeeIDs struct {
 var CommitteeIDs = newCommitteeIDs()
 
 func newCommitteeIDs() *committeeIDs {
-	maxCommitteesPerEpoch := int(params.BeaconConfig().MaxCommitteesPerSlot * params.BeaconConfig().SlotsPerEpoch)
-	attesterCache, err := lru.New(maxCommitteesPerEpoch)
+	// Given a node can calculate committee assignments of current epoch and next epoch.
+	// Max size is set to 2 epoch length.
+	cacheSize := int(params.BeaconConfig().MaxCommitteesPerSlot * params.BeaconConfig().SlotsPerEpoch * 2)
+	attesterCache, err := lru.New(cacheSize)
 	if err != nil {
 		panic(err)
 	}
-	aggregatorCache, err := lru.New(maxCommitteesPerEpoch)
+	aggregatorCache, err := lru.New(cacheSize)
 	if err != nil {
 		panic(err)
 	}

From cb1a4c6f0f5974d49e266ac17e99ce32575de20e Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 3 Apr 2020 21:50:35 -0700
Subject: [PATCH 13/18] Update RPC

---
 beacon-chain/rpc/validator/attester.go | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/beacon-chain/rpc/validator/attester.go b/beacon-chain/rpc/validator/attester.go
index 42b862f3f855..e9b7438622c3 100644
--- a/beacon-chain/rpc/validator/attester.go
+++ b/beacon-chain/rpc/validator/attester.go
@@ -227,10 +227,10 @@ func (vs *Server) waitToOneThird(ctx context.Context, slot uint64) {
 
 // SubscribeCommitteeSubnet subscribes to the committee ID subnet given subscribe request.
 func (vs *Server) SubscribeCommitteeSubnet(ctx context.Context, req *ethpb.CommitteeSubnetSubscribeRequest) (*ptypes.Empty, error) {
+	cache.CommitteeIDs.AddAttesterCommiteeID(req.Slot, req.CommitteeId)
 	if req.IsAggregator {
-		// What should a node cache for an aggregator?
-	} else {
-		cache.CommitteeIDs.AddID(req.Slot, req.CommitteeId)
+		cache.CommitteeIDs.AddAggregatorCommiteeID(req.Slot, req.CommitteeId)
 	}
+
 	return &ptypes.Empty{}, nil
 }

From 3190aa3930590a276602f37b45048e163aa4bb72 Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 3 Apr 2020 21:56:06 -0700
Subject: [PATCH 14/18] Fixed test

---
 beacon-chain/cache/committee_ids.go                       | 8 ++++----
 beacon-chain/p2p/service.go                               | 4 ++--
 beacon-chain/p2p/subnets_test.go                          | 2 +-
 beacon-chain/rpc/validator/attester.go                    | 1 +
 .../sync/subscriber_committee_index_beacon_attestation.go | 4 ++--
 5 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/beacon-chain/cache/committee_ids.go b/beacon-chain/cache/committee_ids.go
index 447f600817c8..4a6a00eb6897 100644
--- a/beacon-chain/cache/committee_ids.go
+++ b/beacon-chain/cache/committee_ids.go
@@ -48,8 +48,8 @@ func (c *committeeIDs) AddAttesterCommiteeID(slot uint64, committeeID uint64) {
 
 // GetAttesterCommitteeIDs gets the committee ID for subscribing subnet for attester of the slot.
 func (c *committeeIDs) GetAttesterCommitteeIDs(slot uint64) []uint64 {
-	c.attesterLock.Lock()
-	defer c.attesterLock.Unlock()
+	c.attesterLock.RLock()
+	defer c.attesterLock.RUnlock()
 
 	val, exists := c.attester.Get(slot)
 	if !exists {
@@ -73,8 +73,8 @@ func (c *committeeIDs) AddAggregatorCommiteeID(slot uint64, committeeID uint64)
 
 // GetAggregatorCommitteeIDs gets the committee ID for subscribing subnet for aggregator of the slot.
 func (c *committeeIDs) GetAggregatorCommitteeIDs(slot uint64) []uint64 {
-	c.aggregatorLock.Lock()
-	defer c.aggregatorLock.Unlock()
+	c.aggregatorLock.RLock()
+	defer c.aggregatorLock.RUnlock()
 
 	val, exists := c.aggregator.Get(slot)
 	if !exists {
diff --git a/beacon-chain/p2p/service.go b/beacon-chain/p2p/service.go
index 189cf196f5a9..c9f905f62c9b 100644
--- a/beacon-chain/p2p/service.go
+++ b/beacon-chain/p2p/service.go
@@ -348,13 +348,13 @@ func (s *Service) MetadataSeq() uint64 {
 // RefreshENR uses an epoch to refresh the enr entry for our node
 // with the tracked committee id's for the epoch, allowing our node
 // to be dynamically discoverable by others given our tracked committee id's.
-func (s *Service) RefreshENR(epoch uint64) {
+func (s *Service) RefreshENR(slot uint64) {
 	// return early if discv5 isnt running
 	if s.dv5Listener == nil {
 		return
 	}
 	bitV := bitfield.NewBitvector64()
-	committees := cache.CommitteeIDs.GetIDs(epoch)
+	committees := cache.CommitteeIDs.GetAttesterCommitteeIDs(slot)
 	for _, idx := range committees {
 		bitV.SetBitAt(idx, true)
 	}
diff --git a/beacon-chain/p2p/subnets_test.go b/beacon-chain/p2p/subnets_test.go
index 9ab6e17d365b..a28259dad605 100644
--- a/beacon-chain/p2p/subnets_test.go
+++ b/beacon-chain/p2p/subnets_test.go
@@ -109,7 +109,7 @@ func TestStartDiscV5_DiscoverPeersWithSubnets(t *testing.T) {
 
 	// Update ENR of a peer.
 	testService := &Service{dv5Listener: listeners[0]}
-	cache.CommitteeIDs.AddID(0, 10)
+	cache.CommitteeIDs.AddAttesterCommiteeID(0, 10)
 	testService.RefreshENR(0)
 	time.Sleep(2 * time.Second)
 
diff --git a/beacon-chain/rpc/validator/attester.go b/beacon-chain/rpc/validator/attester.go
index e9b7438622c3..184143fa757f 100644
--- a/beacon-chain/rpc/validator/attester.go
+++ b/beacon-chain/rpc/validator/attester.go
@@ -228,6 +228,7 @@ func (vs *Server) waitToOneThird(ctx context.Context, slot uint64) {
 // SubscribeCommitteeSubnet subscribes to the committee ID subnet given subscribe request.
 func (vs *Server) SubscribeCommitteeSubnet(ctx context.Context, req *ethpb.CommitteeSubnetSubscribeRequest) (*ptypes.Empty, error) {
 	cache.CommitteeIDs.AddAttesterCommiteeID(req.Slot, req.CommitteeId)
+
 	if req.IsAggregator {
 		cache.CommitteeIDs.AddAggregatorCommiteeID(req.Slot, req.CommitteeId)
 	}
diff --git a/beacon-chain/sync/subscriber_committee_index_beacon_attestation.go b/beacon-chain/sync/subscriber_committee_index_beacon_attestation.go
index a95c91711fd9..d5dad5bf853d 100644
--- a/beacon-chain/sync/subscriber_committee_index_beacon_attestation.go
+++ b/beacon-chain/sync/subscriber_committee_index_beacon_attestation.go
@@ -51,6 +51,6 @@ func (r *Service) committeesCount() int {
 
 func (r *Service) committeeIndices() []uint64 {
 	currentEpoch := helpers.SlotToEpoch(r.chain.HeadSlot())
-	return sliceutil.UnionUint64(cache.CommitteeIDs.GetIDs(currentEpoch),
-		cache.CommitteeIDs.GetIDs(currentEpoch+1))
+	return sliceutil.UnionUint64(cache.CommitteeIDs.GetAttesterCommitteeIDs(currentEpoch),
+		cache.CommitteeIDs.GetAttesterCommitteeIDs(currentEpoch+1))
 }

From 81da6d995f6d87ac9c2cf6b259839207e2ce209f Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 3 Apr 2020 22:14:34 -0700
Subject: [PATCH 15/18] Nishant's comment

---
 beacon-chain/p2p/service.go                                 | 4 +++-
 .../sync/subscriber_committee_index_beacon_attestation.go   | 6 +++---
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/beacon-chain/p2p/service.go b/beacon-chain/p2p/service.go
index c9f905f62c9b..d9a60f2ce793 100644
--- a/beacon-chain/p2p/service.go
+++ b/beacon-chain/p2p/service.go
@@ -34,6 +34,7 @@ import (
 	"github.com/prysmaticlabs/prysm/shared"
 	"github.com/prysmaticlabs/prysm/shared/params"
 	"github.com/prysmaticlabs/prysm/shared/runutil"
+	"github.com/prysmaticlabs/prysm/shared/sliceutil"
 	"github.com/sirupsen/logrus"
 )
 
@@ -354,7 +355,8 @@ func (s *Service) RefreshENR(slot uint64) {
 		return
 	}
 	bitV := bitfield.NewBitvector64()
-	committees := cache.CommitteeIDs.GetAttesterCommitteeIDs(slot)
+	committees := sliceutil.UnionUint64(cache.CommitteeIDs.GetAttesterCommitteeIDs(slot),
+		cache.CommitteeIDs.GetAggregatorCommitteeIDs(slot))
 	for _, idx := range committees {
 		bitV.SetBitAt(idx, true)
 	}
diff --git a/beacon-chain/sync/subscriber_committee_index_beacon_attestation.go b/beacon-chain/sync/subscriber_committee_index_beacon_attestation.go
index d5dad5bf853d..eb5b3e4ae1ad 100644
--- a/beacon-chain/sync/subscriber_committee_index_beacon_attestation.go
+++ b/beacon-chain/sync/subscriber_committee_index_beacon_attestation.go
@@ -50,7 +50,7 @@ func (r *Service) committeesCount() int {
 }
 
 func (r *Service) committeeIndices() []uint64 {
-	currentEpoch := helpers.SlotToEpoch(r.chain.HeadSlot())
-	return sliceutil.UnionUint64(cache.CommitteeIDs.GetAttesterCommitteeIDs(currentEpoch),
-		cache.CommitteeIDs.GetAttesterCommitteeIDs(currentEpoch+1))
+	currentSlot := r.chain.CurrentSlot()
+	return sliceutil.UnionUint64(cache.CommitteeIDs.GetAttesterCommitteeIDs(currentSlot),
+		cache.CommitteeIDs.GetAggregatorCommitteeIDs(currentSlot))
 }

From a8e07844eaa4f25b646f734d44fcf5ab477cca13 Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Fri, 3 Apr 2020 22:24:04 -0700
Subject: [PATCH 16/18] Gaz

---
 beacon-chain/p2p/BUILD.bazel | 1 +
 1 file changed, 1 insertion(+)

diff --git a/beacon-chain/p2p/BUILD.bazel b/beacon-chain/p2p/BUILD.bazel
index 166513e9b002..23f9ace13559 100644
--- a/beacon-chain/p2p/BUILD.bazel
+++ b/beacon-chain/p2p/BUILD.bazel
@@ -43,6 +43,7 @@ go_library(
         "//shared/iputils:go_default_library",
         "//shared/params:go_default_library",
         "//shared/runutil:go_default_library",
+        "//shared/sliceutil:go_default_library",
         "//shared/traceutil:go_default_library",
         "@com_github_btcsuite_btcd//btcec:go_default_library",
         "@com_github_dgraph_io_ristretto//:go_default_library",

From 62f98178f7aa0e1d075ce9ecabf9a0e0072e5bc8 Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Sat, 4 Apr 2020 07:35:37 -0700
Subject: [PATCH 17/18] Refresh ENR is for epoch

---
 beacon-chain/p2p/service.go | 10 +++++++---
 1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/beacon-chain/p2p/service.go b/beacon-chain/p2p/service.go
index d9a60f2ce793..1e4634e66f06 100644
--- a/beacon-chain/p2p/service.go
+++ b/beacon-chain/p2p/service.go
@@ -349,14 +349,18 @@ func (s *Service) MetadataSeq() uint64 {
 // RefreshENR uses an epoch to refresh the enr entry for our node
 // with the tracked committee id's for the epoch, allowing our node
 // to be dynamically discoverable by others given our tracked committee id's.
-func (s *Service) RefreshENR(slot uint64) {
+func (s *Service) RefreshENR(epoch uint64) {
 	// return early if discv5 isnt running
 	if s.dv5Listener == nil {
 		return
 	}
 	bitV := bitfield.NewBitvector64()
-	committees := sliceutil.UnionUint64(cache.CommitteeIDs.GetAttesterCommitteeIDs(slot),
-		cache.CommitteeIDs.GetAggregatorCommitteeIDs(slot))
+
+	var committees []uint64
+	epochStartSlot := helpers.StartSlot(epoch)
+	for i := epochStartSlot; i < epochStartSlot+2*params.BeaconConfig().SlotsPerEpoch; i++ {
+		committees = sliceutil.UnionUint64(cache.CommitteeIDs.GetAttesterCommitteeIDs(i), cache.CommitteeIDs.GetAggregatorCommitteeIDs(i))
+	}
 	for _, idx := range committees {
 		bitV.SetBitAt(idx, true)
 	}

From 9155e7824b85baa1bff6d968b11c0e038faaa094 Mon Sep 17 00:00:00 2001
From: terence tsao <terence@prysmaticlabs.com>
Date: Sat, 4 Apr 2020 07:38:34 -0700
Subject: [PATCH 18/18] Needs to be append

---
 beacon-chain/p2p/service.go | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/beacon-chain/p2p/service.go b/beacon-chain/p2p/service.go
index 1e4634e66f06..3e457d5c315c 100644
--- a/beacon-chain/p2p/service.go
+++ b/beacon-chain/p2p/service.go
@@ -359,7 +359,8 @@ func (s *Service) RefreshENR(epoch uint64) {
 	var committees []uint64
 	epochStartSlot := helpers.StartSlot(epoch)
 	for i := epochStartSlot; i < epochStartSlot+2*params.BeaconConfig().SlotsPerEpoch; i++ {
-		committees = sliceutil.UnionUint64(cache.CommitteeIDs.GetAttesterCommitteeIDs(i), cache.CommitteeIDs.GetAggregatorCommitteeIDs(i))
+		committees = append(committees, sliceutil.UnionUint64(cache.CommitteeIDs.GetAttesterCommitteeIDs(i),
+			cache.CommitteeIDs.GetAggregatorCommitteeIDs(i))...)
 	}
 	for _, idx := range committees {
 		bitV.SetBitAt(idx, true)