roachpb: make range/replica descriptor fields non-nullable

This patch makes all fields in range/replica descriptors non-nullable,
fixing a long-standing TODO.

Additionally, this fixes a set of bugs where code would use regular
comparison operators (e.g. `==`) to compare replica descriptors, which
with nullable pointer fields would compare the memory locations rather
than the values. One practical consequence of this was that the
DistSender would fail to use a new leaseholder with a non-`VOTER` type
(e.g.  `VOTER_INCOMING`), instead continuing to try other replicas
before backing off. However, there are further issues surrounding this
bug and it will be addressed separately in a way that is more amenable
to backporting.

The preparatory work for this was done in ea720e3.

Release note: None

docs/generated/swagger/spec.json

@@ -1322,7 +1322,7 @@
       "x-go-package": "github.com/cockroachdb/cockroach/pkg/server/serverpb"
     },
     "ReplicaDescriptor": {
-      "description": "ReplicaDescriptor describes a replica location by node ID\n(corresponds to a host:port via lookup on gossip network) and store\nID (identifies the device).\nTODO(jeffreyxiao): All nullable fields in ReplicaDescriptor can be made\nnon-nullable if #38302 is guaranteed to be on all nodes (I.E. 20.1).",
+      "description": "ReplicaDescriptor describes a replica location by node ID\n(corresponds to a host:port via lookup on gossip network) and store\nID (identifies the device).",
       "type": "object",
       "properties": {
         "node_id": {

pkg/ccl/kvccl/kvfollowerreadsccl/followerreads_test.go

@@ -660,7 +660,7 @@ func TestFollowerReadsWithStaleDescriptor(t *testing.T) {
 	require.Equal(t, roachpb.StoreID(1), entry.Lease().Replica.StoreID)
 	require.Equal(t, []roachpb.ReplicaDescriptor{
 		{NodeID: 1, StoreID: 1, ReplicaID: 1},
-		{NodeID: 3, StoreID: 3, ReplicaID: 3, Type: roachpb.ReplicaTypeNonVoter()},
+		{NodeID: 3, StoreID: 3, ReplicaID: 3, Type: roachpb.NON_VOTER},
 	}, entry.Desc().Replicas().Descriptors())
 
 	// Make a note of the follower reads metric on n3. We'll check that it was

pkg/cli/debug_recover_loss_of_quorum_test.go

@@ -273,7 +273,6 @@ func createIntentOnRangeDescriptor(
 func TestJsonSerialization(t *testing.T) {
 	defer leaktest.AfterTest(t)()
 
-	rt := roachpb.VOTER_INCOMING
 	nr := loqrecoverypb.NodeReplicaInfo{
 		Replicas: []loqrecoverypb.ReplicaInfo{
 			{
@@ -288,7 +287,7 @@ func TestJsonSerialization(t *testing.T) {
 							NodeID:    1,
 							StoreID:   2,
 							ReplicaID: 3,
-							Type:      &rt,
+							Type:      roachpb.VOTER_INCOMING,
 						},
 					},
 					NextReplicaID: 4,

pkg/kv/kvclient/kvcoord/dist_sender_test.go

@@ -585,7 +585,7 @@ func TestRetryOnNotLeaseHolderError(t *testing.T) {
 
 	recognizedLeaseHolder := testUserRangeDescriptor3Replicas.Replicas().VoterDescriptors()[1]
 	recognizedLeaseHolderIncoming := testUserRangeDescriptor3Replicas.Replicas().VoterDescriptors()[2]
-	recognizedLeaseHolderIncoming.Type = roachpb.ReplicaTypeVoterIncoming()
+	recognizedLeaseHolderIncoming.Type = roachpb.VOTER_INCOMING
 	unrecognizedLeaseHolder := roachpb.ReplicaDescriptor{
 		NodeID:  99,
 		StoreID: 999,
@@ -712,7 +712,7 @@ func TestRetryOnNotLeaseHolderError(t *testing.T) {
 					// initial range descriptor, not the one returned in the NLHE, i.e.
 					// it won't have the non-nil type.
 					expRetryReplica := *tc.expLeaseholder
-					expRetryReplica.Type = nil
+					expRetryReplica.Type = 0
 					require.Equal(t, expRetryReplica, retryReplica)
 				} else {
 					require.Nil(t, rng.Lease())

pkg/kv/kvclient/kvcoord/replica_slice_test.go

@@ -74,8 +74,7 @@ func TestNewReplicaSlice(t *testing.T) {
 	require.Equal(t, 3, rs.Len())
 
 	// Check that learners are not included.
-	typLearner := roachpb.LEARNER
-	rd.InternalReplicas[2].Type = &typLearner
+	rd.InternalReplicas[2].Type = roachpb.LEARNER
 	rs, err = NewReplicaSlice(ctx, ns, rd, nil, OnlyPotentialLeaseholders)
 	require.NoError(t, err)
 	require.Equal(t, 2, rs.Len())
@@ -84,8 +83,7 @@ func TestNewReplicaSlice(t *testing.T) {
 	require.Equal(t, 2, rs.Len())
 
 	// Check that non-voters are included iff we ask for them to be.
-	typNonVoter := roachpb.NON_VOTER
-	rd.InternalReplicas[2].Type = &typNonVoter
+	rd.InternalReplicas[2].Type = roachpb.NON_VOTER
 	rs, err = NewReplicaSlice(ctx, ns, rd, nil, AllExtantReplicas)
 	require.NoError(t, err)
 	require.Equal(t, 3, rs.Len())

pkg/kv/kvclient/kvcoord/split_test.go

@@ -290,7 +290,7 @@ func TestRangeSplitsStickyBit(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if desc.GetStickyBit().IsEmpty() {
+	if desc.StickyBit.IsEmpty() {
 		t.Fatal("Sticky bit not set after splitting")
 	}
 
@@ -309,7 +309,7 @@ func TestRangeSplitsStickyBit(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if desc.GetStickyBit().IsEmpty() {
+	if desc.StickyBit.IsEmpty() {
 		t.Fatal("Sticky bit not set after splitting")
 	}
 }

pkg/kv/kvclient/kvcoord/transport_test.go

@@ -33,7 +33,7 @@ func TestTransportMoveToFront(t *testing.T) {
 	rd2 := roachpb.ReplicaDescriptor{NodeID: 2, StoreID: 2, ReplicaID: 2}
 	rd3 := roachpb.ReplicaDescriptor{NodeID: 3, StoreID: 3, ReplicaID: 3}
 	rd3Incoming := roachpb.ReplicaDescriptor{NodeID: 3, StoreID: 3, ReplicaID: 3,
-		Type: roachpb.ReplicaTypeVoterIncoming()}
+		Type: roachpb.VOTER_INCOMING}
 	gt := grpcTransport{replicas: []roachpb.ReplicaDescriptor{rd1, rd2, rd3}}
 
 	verifyOrder := func(replicas []roachpb.ReplicaDescriptor) {

pkg/kv/kvserver/allocator/allocatorimpl/allocator_test.go

@@ -5678,7 +5678,7 @@ func TestAllocatorComputeAction(t *testing.T) {
 						StoreID:   4,
 						NodeID:    4,
 						ReplicaID: 4,
-						Type:      roachpb.ReplicaTypeNonVoter(),
+						Type:      roachpb.NON_VOTER,
 					},
 				},
 			},
@@ -5754,7 +5754,7 @@ func TestAllocatorComputeAction(t *testing.T) {
 						StoreID:   4,
 						NodeID:    4,
 						ReplicaID: 4,
-						Type:      roachpb.ReplicaTypeNonVoter(),
+						Type:      roachpb.NON_VOTER,
 					},
 				},
 			},
@@ -6032,13 +6032,13 @@ func TestAllocatorComputeAction(t *testing.T) {
 						StoreID:   4,
 						NodeID:    4,
 						ReplicaID: 4,
-						Type:      roachpb.ReplicaTypeNonVoter(),
+						Type:      roachpb.NON_VOTER,
 					},
 					{
 						StoreID:   6,
 						NodeID:    6,
 						ReplicaID: 6,
-						Type:      roachpb.ReplicaTypeNonVoter(),
+						Type:      roachpb.NON_VOTER,
 					},
 				},
 			},
@@ -6090,7 +6090,7 @@ func TestAllocatorComputeAction(t *testing.T) {
 						StoreID:   6,
 						NodeID:    6,
 						ReplicaID: 6,
-						Type:      roachpb.ReplicaTypeNonVoter(),
+						Type:      roachpb.NON_VOTER,
 					},
 				},
 			},
@@ -6113,13 +6113,13 @@ func TestAllocatorComputeAction(t *testing.T) {
 						StoreID:   2,
 						NodeID:    2,
 						ReplicaID: 2,
-						Type:      roachpb.ReplicaTypeNonVoter(),
+						Type:      roachpb.NON_VOTER,
 					},
 					{
 						StoreID:   6,
 						NodeID:    6,
 						ReplicaID: 6,
-						Type:      roachpb.ReplicaTypeNonVoter(),
+						Type:      roachpb.NON_VOTER,
 					},
 				},
 			},
@@ -6143,13 +6143,13 @@ func TestAllocatorComputeAction(t *testing.T) {
 						StoreID:   2,
 						NodeID:    2,
 						ReplicaID: 2,
-						Type:      roachpb.ReplicaTypeNonVoter(),
+						Type:      roachpb.NON_VOTER,
 					},
 					{
 						StoreID:   3,
 						NodeID:    3,
 						ReplicaID: 3,
-						Type:      roachpb.ReplicaTypeNonVoter(),
+						Type:      roachpb.NON_VOTER,
 					},
 				},
 			},
@@ -6646,19 +6646,19 @@ func TestAllocatorComputeActionDecommission(t *testing.T) {
 						StoreID:   4,
 						NodeID:    4,
 						ReplicaID: 4,
-						Type:      roachpb.ReplicaTypeNonVoter(),
+						Type:      roachpb.NON_VOTER,
 					},
 					{
 						StoreID:   6,
 						NodeID:    6,
 						ReplicaID: 6,
-						Type:      roachpb.ReplicaTypeNonVoter(),
+						Type:      roachpb.NON_VOTER,
 					},
 					{
 						StoreID:   7,
 						NodeID:    7,
 						ReplicaID: 7,
-						Type:      roachpb.ReplicaTypeNonVoter(),
+						Type:      roachpb.NON_VOTER,
 					},
 				},
 			},
@@ -6683,13 +6683,13 @@ func TestAllocatorComputeActionDecommission(t *testing.T) {
 						StoreID:   4,
 						NodeID:    4,
 						ReplicaID: 4,
-						Type:      roachpb.ReplicaTypeNonVoter(),
+						Type:      roachpb.NON_VOTER,
 					},
 					{
 						StoreID:   6,
 						NodeID:    6,
 						ReplicaID: 6,
-						Type:      roachpb.ReplicaTypeNonVoter(),
+						Type:      roachpb.NON_VOTER,
 					},
 				},
 			},
@@ -6719,7 +6719,6 @@ func TestAllocatorRemoveLearner(t *testing.T) {
 	defer log.Scope(t).Close(t)
 
 	conf := roachpb.SpanConfig{NumReplicas: 3}
-	learnerType := roachpb.LEARNER
 	rangeWithLearnerDesc := roachpb.RangeDescriptor{
 		InternalReplicas: []roachpb.ReplicaDescriptor{
 			{
@@ -6731,7 +6730,7 @@ func TestAllocatorRemoveLearner(t *testing.T) {
 				StoreID:   2,
 				NodeID:    2,
 				ReplicaID: 2,
-				Type:      &learnerType,
+				Type:      roachpb.LEARNER,
 			},
 		},
 	}

pkg/kv/kvserver/batcheval/cmd_end_transaction.go

@@ -707,11 +707,7 @@ func RunCommitTrigger(
 	}
 	if sbt := ct.GetStickyBitTrigger(); sbt != nil {
 		newDesc := *rec.Desc()
-		if !sbt.StickyBit.IsEmpty() {
-			newDesc.StickyBit = &sbt.StickyBit
-		} else {
-			newDesc.StickyBit = nil
-		}
+		newDesc.StickyBit = sbt.StickyBit
 		var res result.Result
 		res.Replicated.State = &kvserverpb.ReplicaState{
 			Desc: &newDesc,

pkg/kv/kvserver/batcheval/cmd_lease_test.go

@@ -122,8 +122,8 @@ func TestLeaseCommandLearnerReplica(t *testing.T) {
 	ctx := context.Background()
 	const voterStoreID, learnerStoreID roachpb.StoreID = 1, 2
 	replicas := []roachpb.ReplicaDescriptor{
-		{NodeID: 1, StoreID: voterStoreID, Type: roachpb.ReplicaTypeVoterFull(), ReplicaID: 1},
-		{NodeID: 2, StoreID: learnerStoreID, Type: roachpb.ReplicaTypeLearner(), ReplicaID: 2},
+		{NodeID: 1, StoreID: voterStoreID, Type: roachpb.VOTER_FULL, ReplicaID: 1},
+		{NodeID: 2, StoreID: learnerStoreID, Type: roachpb.LEARNER, ReplicaID: 2},
 	}
 	desc := roachpb.RangeDescriptor{}
 	desc.SetReplicas(roachpb.MakeReplicaSet(replicas))
@@ -183,8 +183,8 @@ func TestLeaseTransferForwardsStartTime(t *testing.T) {
 			defer batch.Close()
 
 			replicas := []roachpb.ReplicaDescriptor{
-				{NodeID: 1, StoreID: 1, Type: roachpb.ReplicaTypeVoterFull(), ReplicaID: 1},
-				{NodeID: 2, StoreID: 2, Type: roachpb.ReplicaTypeVoterFull(), ReplicaID: 2},
+				{NodeID: 1, StoreID: 1, Type: roachpb.VOTER_FULL, ReplicaID: 1},
+				{NodeID: 2, StoreID: 2, Type: roachpb.VOTER_FULL, ReplicaID: 2},
 			}
 			desc := roachpb.RangeDescriptor{}
 			desc.SetReplicas(roachpb.MakeReplicaSet(replicas))
@@ -301,15 +301,15 @@ func TestCheckCanReceiveLease(t *testing.T) {
 		t.Run(tc.leaseholderType.String(), func(t *testing.T) {
 			repDesc := roachpb.ReplicaDescriptor{
 				ReplicaID: 1,
-				Type:      &tc.leaseholderType,
+				Type:      tc.leaseholderType,
 			}
 			rngDesc := roachpb.RangeDescriptor{
 				InternalReplicas: []roachpb.ReplicaDescriptor{repDesc},
 			}
 			if tc.anotherReplicaType != none {
 				anotherDesc := roachpb.ReplicaDescriptor{
 					ReplicaID: 2,
-					Type:      &tc.anotherReplicaType,
+					Type:      tc.anotherReplicaType,
 				}
 				rngDesc.InternalReplicas = append(rngDesc.InternalReplicas, anotherDesc)
 			}

pkg/kv/kvserver/client_split_burst_test.go

@@ -78,7 +78,7 @@ func setupSplitBurstTest(t *testing.T, delay time.Duration) *splitBurstTest {
 			if args.Split == nil || delay == 0 {
 				return 0, nil
 			}
-			if args.Split.RightDesc.GetStickyBit() != magicStickyBit {
+			if args.Split.RightDesc.StickyBit != magicStickyBit {
 				return 0, nil
 			}
 			select {

pkg/kv/kvserver/loqrecovery/recovery_env_test.go

@@ -105,10 +105,10 @@ type descriptorViewWrapper struct {
 // for the purpose of yaml representation and to avoid leaking test
 // specific code into production.
 type replicaDescriptorView struct {
-	NodeID      roachpb.NodeID       `yaml:"NodeID"`
-	StoreID     roachpb.StoreID      `yaml:"StoreID"`
-	ReplicaID   roachpb.ReplicaID    `yaml:"ReplicaID"`
-	ReplicaType *roachpb.ReplicaType `yaml:"ReplicaType,omitempty"`
+	NodeID      roachpb.NodeID      `yaml:"NodeID"`
+	StoreID     roachpb.StoreID     `yaml:"StoreID"`
+	ReplicaID   roachpb.ReplicaID   `yaml:"ReplicaID"`
+	ReplicaType roachpb.ReplicaType `yaml:"ReplicaType,omitempty"`
 }
 
 func (r replicaDescriptorView) asReplicaDescriptor() roachpb.ReplicaDescriptor {
@@ -273,7 +273,6 @@ func buildReplicaDescriptorFromTestData(
 		InternalReplicas: replicas,
 		NextReplicaID:    maxReplicaID + 1,
 		Generation:       replica.Generation,
-		StickyBit:        nil,
 	}
 	lease := roachpb.Lease{
 		Start:           clock.Now().Add(5*time.Minute.Nanoseconds(), 0).UnsafeToClockTimestamp(),

pkg/kv/kvserver/merge_queue.go

@@ -237,7 +237,7 @@ func (mq *mergeQueue) process(
 
 	// Range was manually split and not expired, so skip merging.
 	now := mq.store.Clock().NowAsClockTimestamp()
-	if now.ToTimestamp().Less(rhsDesc.GetStickyBit()) {
+	if now.ToTimestamp().Less(rhsDesc.StickyBit) {
 		log.VEventf(ctx, 2, "skipping merge: ranges were manually split and sticky bit was not expired")
 		// TODO(jeffreyxiao): Consider returning a purgatory error to avoid
 		// repeatedly processing ranges that cannot be merged.
@@ -309,7 +309,7 @@ func (mq *mergeQueue) process(
 	// Defensive sanity check that the ranges involved only have either VOTER_FULL
 	// and NON_VOTER replicas.
 	for i := range leftRepls {
-		if typ := leftRepls[i].GetType(); !(typ == roachpb.VOTER_FULL || typ == roachpb.NON_VOTER) {
+		if typ := leftRepls[i].Type; !(typ == roachpb.VOTER_FULL || typ == roachpb.NON_VOTER) {
 			return false,
 				errors.AssertionFailedf(
 					`cannot merge because lhs is either in a joint state or has learner replicas: %v`,
@@ -370,7 +370,7 @@ func (mq *mergeQueue) process(
 		rightRepls = rhsDesc.Replicas().Descriptors()
 	}
 	for i := range rightRepls {
-		if typ := rightRepls[i].GetType(); !(typ == roachpb.VOTER_FULL || typ == roachpb.NON_VOTER) {
+		if typ := rightRepls[i].Type; !(typ == roachpb.VOTER_FULL || typ == roachpb.NON_VOTER) {
 			log.Infof(ctx, "RHS Type: %s", typ)
 			return false,
 				errors.AssertionFailedf(

pkg/kv/kvserver/raft_snapshot_queue.go

@@ -110,7 +110,7 @@ func (rq *raftSnapshotQueue) processRaftSnapshot(
 	}
 	snapType := kvserverpb.SnapshotRequest_VIA_SNAPSHOT_QUEUE
 
-	if typ := repDesc.GetType(); typ == roachpb.LEARNER || typ == roachpb.NON_VOTER {
+	if typ := repDesc.Type; typ == roachpb.LEARNER || typ == roachpb.NON_VOTER {
 		if fn := repl.store.cfg.TestingKnobs.RaftSnapshotQueueSkipReplica; fn != nil && fn() {
 			return false, nil
 		}