raft: remove remnants of MsgStorageApply

Epic: none
Release note: none

Author: pav-kv

pkg/kv/kvserver/replica_raft.go

@@ -1402,8 +1402,6 @@ func splitLocalStorageMsgs(
 				panic("two MsgStorageAppend")
 			}
 			msgStorageAppend = msgs[i]
-		case raftpb.MsgStorageApply:
-			// ignore
 		default:
 			// Local storage messages will always be at the end of the messages slice,
 			// so we can terminate iteration as soon as we reach any other message
@@ -1881,12 +1879,6 @@ func (r *Replica) sendRaftMessages(
 			// Instead, we handle messages to LocalAppendThread inline on the raft
 			// scheduler goroutine, so this code path is unused.
 			panic("unsupported, currently processed inline on raft scheduler goroutine")
-		case raft.LocalApplyThread:
-			// To local apply thread.
-			// NOTE: we don't currently split apply work off into an async goroutine.
-			// Instead, we handle messages to LocalAppendThread inline on the raft
-			// scheduler goroutine, so this code path is unused.
-			panic("unsupported, currently processed inline on raft scheduler goroutine")
 		case raftpb.PeerID(r.ReplicaID()):
 			// To local raft state machine, from local storage append and apply work.
 			// NOTE: For async Raft log appends, these messages come from calls to

pkg/raft/raft.go

@@ -48,10 +48,6 @@ const (
 	// log entries and snapshots to stable storage. The identifier is used as a
 	// target for MsgStorageAppend messages.
 	LocalAppendThread pb.PeerID = math.MaxUint64
-	// LocalApplyThread is a reference to a local thread that applies committed
-	// log entries to the local state machine. The identifier is used as a
-	// target for MsgStorageApply messages.
-	LocalApplyThread pb.PeerID = math.MaxUint64 - 1
 )
 
 // Possible values for CampaignType

pkg/raft/raftpb/raft.proto

@@ -58,8 +58,6 @@ enum MessageType {
   MsgPreVoteResp       = 18;
   MsgStorageAppend     = 19;
   MsgStorageAppendResp = 20;
-  MsgStorageApply      = 21;
-  MsgStorageApplyResp  = 22;
   MsgForgetLeader      = 23;
   MsgFortifyLeader     = 24;
   MsgFortifyLeaderResp = 25;
@@ -68,7 +66,7 @@ enum MessageType {
   // isResponseMsg arrays in raft/util.go and update the corresponding tests in
   // raft/util_test.go.
 
-  reserved 12, 15, 16;
+  reserved 12, 15, 16, 21, 22;
 }
 
 message Message {
@@ -108,7 +106,7 @@ message Message {
   optional bytes       context     = 12 [(gogoproto.nullable) = true];
   // responses are populated by a raft node to instruct storage threads on how
   // to respond and who to respond to when the work associated with a message
-  // is complete. Populated for MsgStorageAppend and MsgStorageApply messages.
+  // is complete. Populated for MsgStorageAppend only.
   repeated Message     responses   = 14 [(gogoproto.nullable) = false];
 
   // match is the log index up to which the follower's log must persistently

pkg/raft/util.go

@@ -33,8 +33,6 @@ var isLocalMsg = [...]bool{
 	pb.MsgSnapStatus:        true,
 	pb.MsgStorageAppend:     true,
 	pb.MsgStorageAppendResp: true,
-	pb.MsgStorageApply:      true,
-	pb.MsgStorageApplyResp:  true,
 }
 
 var isResponseMsg = [...]bool{
@@ -44,7 +42,6 @@ var isResponseMsg = [...]bool{
 	pb.MsgUnreachable:       true,
 	pb.MsgPreVoteResp:       true,
 	pb.MsgStorageAppendResp: true,
-	pb.MsgStorageApplyResp:  true,
 	pb.MsgFortifyLeaderResp: true,
 }
 
@@ -97,7 +94,7 @@ func IsMsgIndicatingLeader(msgt pb.MessageType) bool {
 }
 
 func IsLocalMsgTarget(id pb.PeerID) bool {
-	return id == LocalAppendThread || id == LocalApplyThread
+	return id == LocalAppendThread
 }
 
 // senderHasMsgTerm returns true if the message type is one that should have
@@ -250,8 +247,6 @@ func describeTarget(id pb.PeerID) string {
 		return "None"
 	case LocalAppendThread:
 		return "AppendThread"
-	case LocalApplyThread:
-		return "ApplyThread"
 	default:
 		return fmt.Sprintf("%x", id)
 	}

pkg/raft/util_test.go

@@ -93,8 +93,6 @@ func TestIsLocalMsg(t *testing.T) {
 		{pb.MsgPreVoteResp, false},
 		{pb.MsgStorageAppend, true},
 		{pb.MsgStorageAppendResp, true},
-		{pb.MsgStorageApply, true},
-		{pb.MsgStorageApplyResp, true},
 		{pb.MsgForgetLeader, false},
 		{pb.MsgFortifyLeader, false},
 		{pb.MsgFortifyLeaderResp, false},
@@ -131,8 +129,6 @@ func TestIsResponseMsg(t *testing.T) {
 		{pb.MsgPreVoteResp, true},
 		{pb.MsgStorageAppend, false},
 		{pb.MsgStorageAppendResp, true},
-		{pb.MsgStorageApply, false},
-		{pb.MsgStorageApplyResp, true},
 		{pb.MsgForgetLeader, false},
 		{pb.MsgFortifyLeader, false},
 		{pb.MsgFortifyLeaderResp, true},
@@ -170,8 +166,6 @@ func TestMsgFromLeader(t *testing.T) {
 		{pb.MsgPreVoteResp, false},
 		{pb.MsgStorageAppend, false},
 		{pb.MsgStorageAppendResp, false},
-		{pb.MsgStorageApply, false},
-		{pb.MsgStorageApplyResp, false},
 		{pb.MsgForgetLeader, false},
 		{pb.MsgFortifyLeader, true},
 		{pb.MsgFortifyLeaderResp, false},
@@ -213,8 +207,6 @@ func TestMsgIndicatingLeader(t *testing.T) {
 		{pb.MsgPreVoteResp, false},
 		{pb.MsgStorageAppend, false},
 		{pb.MsgStorageAppendResp, false},
-		{pb.MsgStorageApply, false},
-		{pb.MsgStorageApplyResp, false},
 		{pb.MsgForgetLeader, false},
 		{pb.MsgFortifyLeader, true},
 		{pb.MsgFortifyLeaderResp, false},