From 62eb3bf0fbcc03d2047a57ef8c05dc39f8780334 Mon Sep 17 00:00:00 2001
From: cce <51567+cce@users.noreply.github.com>
Date: Thu, 19 Sep 2024 14:35:14 -0400
Subject: [PATCH] CI: promote unused linter (#6120)

---
 .golangci-warnings.yml                        |  1 -
 .golangci.yml                                 | 11 +++++
 daemon/algod/api/client/restClient.go         | 20 --------
 data/transactions/verify/txn.go               |  1 -
 ledger/store/trackerdb/generickv/schema.go    |  2 +-
 .../sqlitedriver/spVerificationAccessor.go    |  4 +-
 network/msgOfInterest.go                      | 27 +++++------
 network/msgOfInterest_test.go                 |  6 +--
 network/p2p/capabilities.go                   |  2 +-
 network/wsNetwork.go                          |  6 +--
 network/wsNetwork_test.go                     |  7 ++-
 network/wsPeer.go                             | 46 +------------------
 network/wsPeer_test.go                        | 37 +++++++++++++--
 node/node_test.go                             |  4 --
 protocol/tags.go                              | 29 ++++++------
 protocol/tags_test.go                         | 45 ++++++++++++++++--
 shared/pingpong/accounts.go                   |  2 +-
 util/metrics/service.go                       |  8 ----
 18 files changed, 130 insertions(+), 128 deletions(-)

diff --git a/.golangci-warnings.yml b/.golangci-warnings.yml
index 6e58b187c8..d813e97e59 100644
--- a/.golangci-warnings.yml
+++ b/.golangci-warnings.yml
@@ -7,7 +7,6 @@ linters:
   enable:
     - gosec
     - partitiontest
-    - unused
 
 linters-settings:
   gosec: # we are mostly only interested in G601
diff --git a/.golangci.yml b/.golangci.yml
index db13e1d65a..bb44c1ee36 100644
--- a/.golangci.yml
+++ b/.golangci.yml
@@ -19,6 +19,7 @@ linters:
     - staticcheck
     - typecheck
     - paralleltest
+    - unused
 
 severity:
   default-severity: error
@@ -115,6 +116,14 @@ issues:
     - "^superfluous-else: if block ends with"
 
   exclude-rules:
+    - path: cmd/algofix/
+      linters: unused
+    - path: cmd/algocfg/
+      linters: unused
+    - path: cmd/catchpointdump/
+      linters: unused
+    - path: tools/
+      linters: unused
     - path: _test\.go
       linters:
         - errcheck
@@ -129,6 +138,7 @@ issues:
         # - revive
         # - staticcheck
         - typecheck
+        - unused
     - path: _test\.go
       linters:
         - staticcheck
@@ -206,3 +216,4 @@ issues:
         - govet
         - ineffassign
         - misspell
+        - unused
diff --git a/daemon/algod/api/client/restClient.go b/daemon/algod/api/client/restClient.go
index a3dc4b769e..c349d3ecbf 100644
--- a/daemon/algod/api/client/restClient.go
+++ b/daemon/algod/api/client/restClient.go
@@ -347,26 +347,6 @@ type pendingTransactionsByAddrParams struct {
 	Max uint64 `url:"max"`
 }
 
-type transactionsByAddrParams struct {
-	FirstRound uint64 `url:"firstRound"`
-	LastRound  uint64 `url:"lastRound"`
-	Max        uint64 `url:"max"`
-}
-
-type assetsParams struct {
-	AssetIdx uint64 `url:"assetIdx"`
-	Max      uint64 `url:"max"`
-}
-
-type appsParams struct {
-	AppIdx uint64 `url:"appIdx"`
-	Max    uint64 `url:"max"`
-}
-
-type rawblockParams struct {
-	Raw uint64 `url:"raw"`
-}
-
 type rawFormat struct {
 	Format string `url:"format"`
 }
diff --git a/data/transactions/verify/txn.go b/data/transactions/verify/txn.go
index a345c679af..d0f38bca90 100644
--- a/data/transactions/verify/txn.go
+++ b/data/transactions/verify/txn.go
@@ -81,7 +81,6 @@ type GroupContext struct {
 }
 
 var errTxGroupInvalidFee = errors.New("txgroup fee requirement overflow")
-var errTxGroupInsuffientLsigBudget = errors.New("txgroup lsig expectations exceed available budget")
 var errTxnSigHasNoSig = errors.New("signedtxn has no sig")
 var errTxnSigNotWellFormed = errors.New("signedtxn should only have one of Sig or Msig or LogicSig")
 var errRekeyingNotSupported = errors.New("nonempty AuthAddr but rekeying is not supported")
diff --git a/ledger/store/trackerdb/generickv/schema.go b/ledger/store/trackerdb/generickv/schema.go
index 47168a1288..cabbd8f13d 100644
--- a/ledger/store/trackerdb/generickv/schema.go
+++ b/ledger/store/trackerdb/generickv/schema.go
@@ -133,7 +133,7 @@ func creatableKey(cidx basics.CreatableIndex) [11]byte {
 	return key
 }
 
-func creatableMaxRangePrefix(maxIdx basics.CreatableIndex) ([3]byte, [11]byte) {
+func creatableMaxRangePrefix(maxIdx basics.CreatableIndex) ([3]byte, [11]byte) { //nolint:unused // TODO
 	var low [prefixLength + separatorLength]byte
 
 	copy(low[0:], kvPrefixCreatorIndex)
diff --git a/ledger/store/trackerdb/sqlitedriver/spVerificationAccessor.go b/ledger/store/trackerdb/sqlitedriver/spVerificationAccessor.go
index b5eb3f0cc3..d9b1814c8a 100644
--- a/ledger/store/trackerdb/sqlitedriver/spVerificationAccessor.go
+++ b/ledger/store/trackerdb/sqlitedriver/spVerificationAccessor.go
@@ -35,7 +35,7 @@ type stateProofVerificationWriter struct {
 	e db.Executable
 }
 
-type stateProofVerificationReaderWriter struct {
+type stateProofVerificationReaderWriter struct { //nolint:unused // TODO
 	stateProofVerificationReader
 	stateProofVerificationWriter
 }
@@ -48,7 +48,7 @@ func makeStateProofVerificationWriter(e db.Executable) *stateProofVerificationWr
 	return &stateProofVerificationWriter{e: e}
 }
 
-func makeStateProofVerificationReaderWriter(q db.Queryable, e db.Executable) *stateProofVerificationReaderWriter {
+func makeStateProofVerificationReaderWriter(q db.Queryable, e db.Executable) *stateProofVerificationReaderWriter { //nolint:unused // TODO
 	return &stateProofVerificationReaderWriter{
 		stateProofVerificationReader{q: q},
 		stateProofVerificationWriter{e: e},
diff --git a/network/msgOfInterest.go b/network/msgOfInterest.go
index 727405c8a8..be1c7d735e 100644
--- a/network/msgOfInterest.go
+++ b/network/msgOfInterest.go
@@ -50,6 +50,9 @@ func unmarshallMessageOfInterest(data []byte) (map[protocol.Tag]bool, error) {
 		if len(tag) != protocol.TagLength {
 			return nil, errInvalidMessageOfInterestInvalidTag
 		}
+		if _, ok := protocol.DeprecatedTagMap[protocol.Tag(tag)]; ok {
+			continue
+		}
 		if _, ok := protocol.TagMap[protocol.Tag(tag)]; !ok {
 			return nil, errInvalidMessageOfInterestInvalidTag
 		}
@@ -58,23 +61,18 @@ func unmarshallMessageOfInterest(data []byte) (map[protocol.Tag]bool, error) {
 	return msgTagsMap, nil
 }
 
-// MarshallMessageOfInterest generate a message of interest message body for a given set of message tags.
-func MarshallMessageOfInterest(messageTags []protocol.Tag) []byte {
-	// create a long string with all these messages.
-	tags := ""
+// marshallMessageOfInterest generates a message of interest message body for a given set of message tags.
+func marshallMessageOfInterest(messageTags []protocol.Tag) []byte {
+	m := make(map[protocol.Tag]bool)
 	for _, tag := range messageTags {
-		tags += topicsEncodingSeparator + string(tag)
-	}
-	if len(tags) > 0 {
-		tags = tags[len(topicsEncodingSeparator):]
+		m[tag] = true
 	}
-	topics := Topics{Topic{key: "tags", data: []byte(tags)}}
-	return topics.MarshallTopics()
+	return marshallMessageOfInterestMap(m)
 }
 
-// MarshallMessageOfInterestMap generates a message of interest message body
+// marshallMessageOfInterestMap generates a message of interest message body
 // for the message tags that map to "true" in the map argument.
-func MarshallMessageOfInterestMap(tagmap map[protocol.Tag]bool) []byte {
+func marshallMessageOfInterestMap(tagmap map[protocol.Tag]bool) []byte {
 	tags := ""
 	for tag, flag := range tagmap {
 		if flag {
@@ -95,5 +93,8 @@ func MessageOfInterestMaxSize() int {
 	for _, tag := range protocol.TagList {
 		allTags[tag] = true
 	}
-	return len(MarshallMessageOfInterest(protocol.TagList))
+	for tag := range protocol.DeprecatedTagMap {
+		allTags[tag] = true
+	}
+	return len(marshallMessageOfInterestMap(allTags))
 }
diff --git a/network/msgOfInterest_test.go b/network/msgOfInterest_test.go
index ef13c6c0cc..b8e2c85249 100644
--- a/network/msgOfInterest_test.go
+++ b/network/msgOfInterest_test.go
@@ -51,20 +51,20 @@ func TestUnmarshallMessageOfInterestErrors(t *testing.T) {
 func TestMarshallMessageOfInterest(t *testing.T) {
 	partitiontest.PartitionTest(t)
 
-	bytes := MarshallMessageOfInterest([]protocol.Tag{protocol.AgreementVoteTag})
+	bytes := marshallMessageOfInterest([]protocol.Tag{protocol.AgreementVoteTag})
 	tags, err := unmarshallMessageOfInterest(bytes)
 	require.NoError(t, err)
 	require.Equal(t, tags[protocol.AgreementVoteTag], true)
 	require.Equal(t, 1, len(tags))
 
-	bytes = MarshallMessageOfInterest([]protocol.Tag{protocol.AgreementVoteTag, protocol.NetPrioResponseTag})
+	bytes = marshallMessageOfInterest([]protocol.Tag{protocol.AgreementVoteTag, protocol.NetPrioResponseTag})
 	tags, err = unmarshallMessageOfInterest(bytes)
 	require.NoError(t, err)
 	require.Equal(t, tags[protocol.AgreementVoteTag], true)
 	require.Equal(t, tags[protocol.NetPrioResponseTag], true)
 	require.Equal(t, 2, len(tags))
 
-	bytes = MarshallMessageOfInterest([]protocol.Tag{protocol.AgreementVoteTag, protocol.AgreementVoteTag})
+	bytes = marshallMessageOfInterest([]protocol.Tag{protocol.AgreementVoteTag, protocol.AgreementVoteTag})
 	tags, err = unmarshallMessageOfInterest(bytes)
 	require.NoError(t, err)
 	require.Equal(t, tags[protocol.AgreementVoteTag], true)
diff --git a/network/p2p/capabilities.go b/network/p2p/capabilities.go
index 7a418767d1..6b79ad7d3e 100644
--- a/network/p2p/capabilities.go
+++ b/network/p2p/capabilities.go
@@ -79,7 +79,7 @@ func (c *CapabilitiesDiscovery) Host() host.Host {
 }
 
 // addPeer adds a given peer.AddrInfo to the Host's Peerstore, and the DHT's routing table
-func (c *CapabilitiesDiscovery) addPeer(p peer.AddrInfo) (bool, error) {
+func (c *CapabilitiesDiscovery) addPeer(p peer.AddrInfo) (bool, error) { //nolint:unused // TODO
 	c.Host().Peerstore().AddAddrs(p.ID, p.Addrs, libpeerstore.AddressTTL)
 	return c.dht.RoutingTable().TryAddPeer(p.ID, true, true)
 }
diff --git a/network/wsNetwork.go b/network/wsNetwork.go
index 5ab45e0406..1c5774aa6e 100644
--- a/network/wsNetwork.go
+++ b/network/wsNetwork.go
@@ -658,7 +658,7 @@ func (wn *WebsocketNetwork) Start() error {
 	defer wn.messagesOfInterestMu.Unlock()
 	wn.messagesOfInterestEncoded = true
 	if wn.messagesOfInterest != nil {
-		wn.messagesOfInterestEnc = MarshallMessageOfInterestMap(wn.messagesOfInterest)
+		wn.messagesOfInterestEnc = marshallMessageOfInterestMap(wn.messagesOfInterest)
 	}
 
 	if wn.config.IsGossipServer() || wn.config.ForceRelayMessages {
@@ -818,7 +818,7 @@ func (wn *WebsocketNetwork) RegisterHandlers(dispatch []TaggedMessageHandler) {
 // ClearHandlers deregisters all the existing message handlers.
 func (wn *WebsocketNetwork) ClearHandlers() {
 	// exclude the internal handlers. These would get cleared out when Stop is called.
-	wn.handler.ClearHandlers([]Tag{protocol.PingTag, protocol.PingReplyTag, protocol.NetPrioResponseTag})
+	wn.handler.ClearHandlers([]Tag{protocol.NetPrioResponseTag})
 }
 
 // RegisterValidatorHandlers registers the set of given message handlers.
@@ -2468,7 +2468,7 @@ func (wn *WebsocketNetwork) DeregisterMessageInterest(t protocol.Tag) {
 
 func (wn *WebsocketNetwork) updateMessagesOfInterestEnc() {
 	// must run inside wn.messagesOfInterestMu.Lock
-	wn.messagesOfInterestEnc = MarshallMessageOfInterestMap(wn.messagesOfInterest)
+	wn.messagesOfInterestEnc = marshallMessageOfInterestMap(wn.messagesOfInterest)
 	wn.messagesOfInterestEncoded = true
 	wn.messagesOfInterestGeneration.Add(1)
 	var peers []*wsPeer
diff --git a/network/wsNetwork_test.go b/network/wsNetwork_test.go
index 91983dfa20..1a355e5250 100644
--- a/network/wsNetwork_test.go
+++ b/network/wsNetwork_test.go
@@ -2904,7 +2904,7 @@ func TestWebsocketNetworkMessageOfInterest(t *testing.T) {
 	partitiontest.PartitionTest(t)
 	var (
 		ft1 = protocol.Tag("AV")
-		ft2 = protocol.Tag("pj")
+		ft2 = protocol.Tag("UE")
 		ft3 = protocol.Tag("NI")
 		ft4 = protocol.Tag("TX")
 
@@ -2924,9 +2924,8 @@ func TestWebsocketNetworkMessageOfInterest(t *testing.T) {
 	t.Logf("netA %s", addrA)
 	netB.phonebook.ReplacePeerList([]string{addrA}, "default", phonebook.PhoneBookEntryRelayRole)
 
-	// have netB asking netA to send it ft2, deregister ping handler to make sure that we aren't exceeding the maximum MOI messagesize
+	// have netB asking netA to send it ft2.
 	// Max MOI size is calculated by encoding all of the valid tags, since we are using a custom tag here we must deregister one in the default set.
-	netB.DeregisterMessageInterest(protocol.PingTag)
 	netB.registerMessageInterest(ft2)
 
 	netB.Start()
@@ -3845,7 +3844,7 @@ func (t mockHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		return
 	}
 
-	bytes := MarshallMessageOfInterest([]protocol.Tag{protocol.AgreementVoteTag})
+	bytes := marshallMessageOfInterest([]protocol.Tag{protocol.AgreementVoteTag})
 	msgBytes := append([]byte(protocol.MsgOfInterestTag), bytes...)
 	_, err = wr.Write(msgBytes)
 	if err != nil {
diff --git a/network/wsPeer.go b/network/wsPeer.go
index a6a982af59..2b30a17486 100644
--- a/network/wsPeer.go
+++ b/network/wsPeer.go
@@ -76,8 +76,6 @@ var defaultSendMessageTags = map[protocol.Tag]bool{
 	protocol.MsgDigestSkipTag:     true,
 	protocol.NetPrioResponseTag:   true,
 	protocol.NetIDVerificationTag: true,
-	protocol.PingTag:              true,
-	protocol.PingReplyTag:         true,
 	protocol.ProposalPayloadTag:   true,
 	protocol.TopicMsgRespTag:      true,
 	protocol.MsgOfInterestTag:     true,
@@ -142,7 +140,6 @@ type disconnectReason string
 
 const disconnectReasonNone disconnectReason = ""
 const disconnectBadData disconnectReason = "BadData"
-const disconnectTooSlow disconnectReason = "TooSlow"
 const disconnectReadError disconnectReason = "ReadError"
 const disconnectWriteError disconnectReason = "WriteError"
 const disconnectIdleConn disconnectReason = "IdleConnection"
@@ -226,12 +223,6 @@ type wsPeer struct {
 
 	processed chan struct{}
 
-	pingLock              deadlock.Mutex
-	pingSent              time.Time
-	pingData              []byte
-	pingInFlight          bool
-	lastPingRoundTripTime time.Duration
-
 	// Hint about position in wn.peers.  Definitely valid if the peer
 	// is present in wn.peers.
 	peerIndex int
@@ -684,8 +675,7 @@ func (wp *wsPeer) readLoop() {
 		case protocol.ProposalPayloadTag:
 			wp.ppMessageCount.Add(1)
 		// the remaining valid tags: no special handling here
-		case protocol.NetPrioResponseTag, protocol.PingTag, protocol.PingReplyTag,
-			protocol.StateProofSigTag, protocol.UniEnsBlockReqTag, protocol.VoteBundleTag, protocol.NetIDVerificationTag:
+		case protocol.NetPrioResponseTag, protocol.StateProofSigTag, protocol.UniEnsBlockReqTag, protocol.VoteBundleTag, protocol.NetIDVerificationTag:
 		default: // unrecognized tag
 			unknownProtocolTagMessagesTotal.Inc(nil)
 			wp.unkMessageCount.Add(1)
@@ -951,40 +941,6 @@ func (wp *wsPeer) writeNonBlockMsgs(ctx context.Context, data [][]byte, highPrio
 
 // PingLength is the fixed length of ping message, exported to be used in the node.TestMaxSizesCorrect test
 const PingLength = 8
-const maxPingWait = 60 * time.Second
-
-// sendPing sends a ping block to the peer.
-// return true if either a ping request was enqueued or there is already ping request in flight in the past maxPingWait time.
-func (wp *wsPeer) sendPing() bool {
-	wp.pingLock.Lock()
-	defer wp.pingLock.Unlock()
-	now := time.Now()
-	if wp.pingInFlight && (now.Sub(wp.pingSent) < maxPingWait) {
-		return true
-	}
-
-	tagBytes := []byte(protocol.PingTag)
-	mbytes := make([]byte, len(tagBytes)+PingLength)
-	copy(mbytes, tagBytes)
-	crypto.RandBytes(mbytes[len(tagBytes):])
-	wp.pingData = mbytes[len(tagBytes):]
-	sent := wp.writeNonBlock(context.Background(), mbytes, false, crypto.Digest{}, time.Now())
-
-	if sent {
-		wp.pingInFlight = true
-		wp.pingSent = now
-	}
-	return sent
-}
-
-// get some times out of the peer while observing the ping data lock
-func (wp *wsPeer) pingTimes() (lastPingSent time.Time, lastPingRoundTripTime time.Duration) {
-	wp.pingLock.Lock()
-	defer wp.pingLock.Unlock()
-	lastPingSent = wp.pingSent
-	lastPingRoundTripTime = wp.lastPingRoundTripTime
-	return
-}
 
 // called when the connection had an error or closed remotely
 func (wp *wsPeer) internalClose(reason disconnectReason) {
diff --git a/network/wsPeer_test.go b/network/wsPeer_test.go
index 973c027b16..ff1f9be7bc 100644
--- a/network/wsPeer_test.go
+++ b/network/wsPeer_test.go
@@ -241,21 +241,49 @@ func getProtocolTags(t *testing.T) []string {
 	fset := token.NewFileSet()
 	f, _ := parser.ParseFile(fset, file, nil, parser.ParseComments)
 
+	// get deprecated tags
+	deprecatedTags := make(map[string]bool)
+	for _, d := range f.Decls {
+		genDecl, ok := d.(*ast.GenDecl)
+		if !ok || genDecl.Tok != token.VAR {
+			continue
+		}
+		for _, spec := range genDecl.Specs {
+			if valueSpec, ok := spec.(*ast.ValueSpec); ok && len(valueSpec.Names) > 0 &&
+				valueSpec.Names[0].Name == "DeprecatedTagList" {
+				for _, v := range valueSpec.Values {
+					cl, ok := v.(*ast.CompositeLit)
+					if !ok {
+						continue
+					}
+					for _, elt := range cl.Elts {
+						if ce, ok := elt.(*ast.Ident); ok {
+							deprecatedTags[ce.Name] = true
+						}
+					}
+				}
+			}
+		}
+	}
+
 	// look for const declarations in protocol/tags.go
 	var declaredTags []string
 	// Iterate through the declarations in the file
 	for _, d := range f.Decls {
 		genDecl, ok := d.(*ast.GenDecl)
-		// Check if the declaration is a constant and if not, continue
+		// Check if the declaration is a constant
 		if !ok || genDecl.Tok != token.CONST {
 			continue
 		}
 		// Iterate through the specs (specifications) in the declaration
 		for _, spec := range genDecl.Specs {
 			if valueSpec, ok := spec.(*ast.ValueSpec); ok {
+				if ident, isIdent := valueSpec.Type.(*ast.Ident); !isIdent || ident.Name != "Tag" {
+					continue // skip all but Tag constants
+				}
 				for _, n := range valueSpec.Names {
-					if strings.HasSuffix(n.Name, "MaxSize") || n.Name == "TagLength" {
-						continue
+					if deprecatedTags[n.Name] {
+						continue // skip deprecated tags
 					}
 					declaredTags = append(declaredTags, n.Name)
 				}
@@ -263,7 +291,8 @@ func getProtocolTags(t *testing.T) []string {
 		}
 	}
 	// assert these AST-discovered tags are complete (match the size of protocol.TagList)
-	require.Len(t, declaredTags, len(protocol.TagList))
+	require.Len(t, protocol.TagList, len(declaredTags))
+	require.Len(t, protocol.DeprecatedTagList, len(deprecatedTags))
 	return declaredTags
 }
 
diff --git a/node/node_test.go b/node/node_test.go
index d35ac43d98..387ea58aa8 100644
--- a/node/node_test.go
+++ b/node/node_test.go
@@ -798,10 +798,6 @@ func TestMaxSizesCorrect(t *testing.T) {
 	require.Equal(t, npSize, protocol.NetPrioResponseTag.MaxMessageSize())
 	nsSize := uint64(network.IdentityVerificationMessageSignedMaxSize())
 	require.Equal(t, nsSize, protocol.NetIDVerificationTag.MaxMessageSize())
-	piSize := uint64(network.PingLength)
-	require.Equal(t, piSize, protocol.PingTag.MaxMessageSize())
-	pjSize := uint64(network.PingLength)
-	require.Equal(t, pjSize, protocol.PingReplyTag.MaxMessageSize())
 	ppSize := uint64(agreement.TransmittedPayloadMaxSize())
 	require.Equal(t, ppSize, protocol.ProposalPayloadTag.MaxMessageSize())
 	spSize := uint64(stateproof.SigFromAddrMaxSize())
diff --git a/protocol/tags.go b/protocol/tags.go
index cdae9c6cdc..3a443c05cf 100644
--- a/protocol/tags.go
+++ b/protocol/tags.go
@@ -33,8 +33,8 @@ const (
 	MsgDigestSkipTag     Tag = "MS"
 	NetPrioResponseTag   Tag = "NP"
 	NetIDVerificationTag Tag = "NI"
-	PingTag              Tag = "pi"
-	PingReplyTag         Tag = "pj"
+	PingTag              Tag = "pi" // was removed in 3.2.1
+	PingReplyTag         Tag = "pj" // was removed in 3.2.1
 	ProposalPayloadTag   Tag = "PP"
 	StateProofSigTag     Tag = "SP"
 	TopicMsgRespTag      Tag = "TS"
@@ -65,12 +65,6 @@ const NetPrioResponseTagMaxSize = 850
 // NetIDVerificationTagMaxSize is the maximum size of a NetIDVerificationTag message
 const NetIDVerificationTagMaxSize = 215
 
-// PingTagMaxSize is the maximum size of a PingTag message
-const PingTagMaxSize = 8
-
-// PingReplyTagMaxSize is the maximum size of a PingReplyTag message
-const PingReplyTagMaxSize = 8
-
 // ProposalPayloadTagMaxSize is the maximum size of a ProposalPayloadTag message
 // This value is dominated by the MaxTxnBytesPerBlock
 const ProposalPayloadTagMaxSize = 5250313
@@ -122,10 +116,6 @@ func (tag Tag) MaxMessageSize() uint64 {
 		return NetPrioResponseTagMaxSize
 	case NetIDVerificationTag:
 		return NetIDVerificationTagMaxSize
-	case PingTag:
-		return PingTagMaxSize
-	case PingReplyTag:
-		return PingReplyTagMaxSize
 	case ProposalPayloadTag:
 		return ProposalPayloadTagMaxSize
 	case StateProofSigTag:
@@ -150,8 +140,6 @@ var TagList = []Tag{
 	MsgDigestSkipTag,
 	NetIDVerificationTag,
 	NetPrioResponseTag,
-	PingTag,
-	PingReplyTag,
 	ProposalPayloadTag,
 	StateProofSigTag,
 	TopicMsgRespTag,
@@ -160,12 +148,25 @@ var TagList = []Tag{
 	VoteBundleTag,
 }
 
+// DeprecatedTagList contains tags that are no longer used, but may still show up in MsgOfInterest messages.
+var DeprecatedTagList = []Tag{
+	PingTag,
+	PingReplyTag,
+}
+
 // TagMap is a map of all currently used protocol tags.
 var TagMap map[Tag]struct{}
 
+// DeprecatedTagMap is a map of all deprecated protocol tags.
+var DeprecatedTagMap map[Tag]struct{}
+
 func init() {
 	TagMap = make(map[Tag]struct{})
 	for _, tag := range TagList {
 		TagMap[tag] = struct{}{}
 	}
+	DeprecatedTagMap = make(map[Tag]struct{})
+	for _, tag := range DeprecatedTagList {
+		DeprecatedTagMap[tag] = struct{}{}
+	}
 }
diff --git a/protocol/tags_test.go b/protocol/tags_test.go
index 69c3146cf9..d4440a45cc 100644
--- a/protocol/tags_test.go
+++ b/protocol/tags_test.go
@@ -78,6 +78,37 @@ func getConstValues(t *testing.T, fileName string, typeName string, namesOnly bo
 	return ret
 }
 
+func getDeprecatedTags(t *testing.T) map[string]bool {
+	fset := token.NewFileSet()
+	f, _ := parser.ParseFile(fset, "tags.go", nil, 0)
+
+	deprecatedTags := make(map[string]bool)
+	for _, d := range f.Decls {
+		genDecl, ok := d.(*ast.GenDecl)
+		if !ok || genDecl.Tok != token.VAR {
+			continue
+		}
+		for _, spec := range genDecl.Specs {
+			if valueSpec, ok := spec.(*ast.ValueSpec); ok && len(valueSpec.Names) > 0 &&
+				valueSpec.Names[0].Name == "DeprecatedTagList" {
+				for _, v := range valueSpec.Values {
+					cl, ok := v.(*ast.CompositeLit)
+					if !ok {
+						continue
+					}
+					for _, elt := range cl.Elts {
+						if ce, ok := elt.(*ast.Ident); ok {
+							deprecatedTags[ce.Name] = true
+						}
+					}
+				}
+			}
+		}
+	}
+
+	return deprecatedTags
+}
+
 // TestTagList checks that the TagList global variable contains
 // all the constant Tag variables declared in tags.go.
 func TestTagList(t *testing.T) {
@@ -88,11 +119,16 @@ func TestTagList(t *testing.T) {
 
 	// Verify that TagList is not empty and has the same length as constTags
 	require.NotEmpty(t, TagList)
-	require.Len(t, TagList, len(constTags), "TagList is not complete")
+	require.Len(t, TagList, len(constTags)-len(DeprecatedTagMap), "TagList is not complete")
 	tagListMap := make(map[Tag]bool)
 	for _, tag := range TagList {
 		tagListMap[tag] = true
 	}
+	for tag := range DeprecatedTagMap {
+		// ensure deprecated tags are not in TagList
+		require.False(t, tagListMap[tag])
+		tagListMap[tag] = true
+	}
 	// Iterate through constTags and check that each element exists in tagListMap
 	for _, constTag := range constTags {
 		if tagListMap[Tag(constTag)] {
@@ -168,11 +204,16 @@ func TestMaxSizesTested(t *testing.T) {
 		}
 	}
 
+	deprecatedTags := getDeprecatedTags(t)
 	for _, tag := range constTags {
 		if tag == "TxnTag" {
 			// TxnTag is tested in a looser way in TestMaxSizesCorrect
 			continue
 		}
+		if deprecatedTags[tag] {
+			continue
+		}
+
 		require.Truef(t, tagsFound[tag], "Tag %s does not have a corresponding test in TestMaxSizesCorrect", tag)
 	}
 }
@@ -242,8 +283,6 @@ func TestLockdownTagList(t *testing.T) {
 		MsgDigestSkipTag,
 		NetIDVerificationTag,
 		NetPrioResponseTag,
-		PingTag,
-		PingReplyTag,
 		ProposalPayloadTag,
 		StateProofSigTag,
 		TopicMsgRespTag,
diff --git a/shared/pingpong/accounts.go b/shared/pingpong/accounts.go
index 99eb4b25bc..8ac9c44a87 100644
--- a/shared/pingpong/accounts.go
+++ b/shared/pingpong/accounts.go
@@ -958,7 +958,7 @@ func (pps *WorkerState) appFundFromSourceAccount(appID uint64, client *libgoal.C
 	return nil
 }
 
-func takeTopAccounts(allAccounts map[string]*pingPongAccount, numAccounts uint32, srcAccount string) (accounts map[string]*pingPongAccount) {
+func takeTopAccounts(allAccounts map[string]*pingPongAccount, numAccounts uint32, srcAccount string) (accounts map[string]*pingPongAccount) { //nolint:unused // TODO
 	allAddrs := make([]string, len(allAccounts))
 	var i int
 	for addr := range allAccounts {
diff --git a/util/metrics/service.go b/util/metrics/service.go
index e579fd01a1..c7089470c6 100644
--- a/util/metrics/service.go
+++ b/util/metrics/service.go
@@ -22,7 +22,6 @@ import (
 	"errors"
 	"os"
 	"strconv"
-	"time"
 )
 
 var (
@@ -34,13 +33,6 @@ var (
 	ErrMetricUnableToRegister = errors.New("Unable to register metric")
 )
 
-var (
-	// the duration of which we'll keep a metric in-memory and keep reporting it.
-	// when a metric time expires, it would get removed.
-	// TODO: implement or remove
-	maxMetricRetensionDuration = time.Duration(5) * time.Minute
-)
-
 // MakeMetricService creates a new metrics server at the given endpoint.
 func MakeMetricService(config *ServiceConfig) *MetricService {
 	server := &MetricService{