mirrors/tailscale
1
0
Fork 0
mirror of https://github.com/tailscale/tailscale.git synced 2026-05-05 12:16:44 +02:00
Code Issues Packages Projects Releases Wiki Activity

control/controlclient: add patchify miss stats

Browse Source 
Add an opt-in metrics.LabelMap tracking why patchifyPeer fails to
convert a PeersChanged entry into a PeersChangedPatch. The stats are
gated behind the TS_DEBUG_PATCHIFY_PEER_MISS envknob so there is zero
overhead in normal operation.

peerChangeDiff now takes an optional onFalse callback that is called
with the field name on every non-patchable return path. When the
envknob is off, nil is passed and replaced with a no-op at the top of
peerChangeDiff.

The resulting metric renders as:

    counter_patchify_miss{why="Hostinfo"} 2
    counter_patchify_miss{why="peer_not_found"} 1170

Updates tailscale/corp#40088

Change-Id: I2d4b9074bf42ec03ab296c0629a54106bafa873e
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick 2026-04-15 14:37:33 +00:00 committed by Brad Fitzpatrick
parent 61c95f409c
commit dbf468740b
3 changed files with 59 additions and 6 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

45
control/controlclient/map.go
View File

@ -835,13 +835,22 @@ func (ms *mapSession) addUserProfile(nm *netmap.NetworkMap, userID tailcfg.UserI
}
var debugPatchifyPeer = envknob.RegisterBool("TS_DEBUG_PATCHIFY_PEER")
var debugPatchifyPeerMiss = envknob.RegisterBool("TS_DEBUG_PATCHIFY_PEER_MISS")
// patchifyMissOnFalse, if non-nil, is called with the field name when
// patchifyPeer fails. It is set by an init func in map_debug.go.
var patchifyMissOnFalse func(string)
// patchifyPeersChanged mutates resp to promote PeersChanged entries to PeersChangedPatch
// when possible.
func (ms *mapSession) patchifyPeersChanged(resp *tailcfg.MapResponse) {
var onFalse func(string)
if debugPatchifyPeerMiss() {
onFalse = patchifyMissOnFalse
}
filtered := resp.PeersChanged[:0]
for _, n := range resp.PeersChanged {
if p, ok := ms.patchifyPeer(n); ok {
if p, ok := ms.patchifyPeer(n, onFalse); ok {
patchifiedPeer.Add(1)
if debugPatchifyPeer() {
patchj, _ := json.Marshal(p)
@ -879,21 +888,27 @@ func getNodeFields() []string {
//
// It returns ok=false if a patch can't be made, (V, ok) on a delta, or (nil,
// true) if all the fields were identical (a zero change).
func (ms *mapSession) patchifyPeer(n *tailcfg.Node) (_ *tailcfg.PeerChange, ok bool) {
func (ms *mapSession) patchifyPeer(n *tailcfg.Node, onFalse func(string)) (_ *tailcfg.PeerChange, ok bool) {
ms.peersMu.RLock()
defer ms.peersMu.RUnlock()
was, ok := ms.peers[n.ID]
if !ok {
if onFalse != nil {
onFalse("peer_not_found")
}
return nil, false
}
return peerChangeDiff(was, n)
return peerChangeDiff(was, n, onFalse)
}
// peerChangeDiff returns the difference from 'was' to 'n', if possible.
//
// It returns (nil, true) if the fields were identical.
func peerChangeDiff(was tailcfg.NodeView, n *tailcfg.Node) (_ *tailcfg.PeerChange, ok bool) {
func peerChangeDiff(was tailcfg.NodeView, n *tailcfg.Node, onFalse func(string)) (_ *tailcfg.PeerChange, ok bool) {
if onFalse == nil {
onFalse = func(string) {}
}
var ret *tailcfg.PeerChange
pc := func() *tailcfg.PeerChange {
if ret == nil {
@ -917,22 +932,27 @@ func peerChangeDiff(was tailcfg.NodeView, n *tailcfg.Node) (_ *tailcfg.PeerChang
// And it was never sent by any known control server.
case "ID":
if was.ID() != n.ID {
onFalse(field)
return nil, false
}
case "StableID":
if was.StableID() != n.StableID {
onFalse(field)
return nil, false
}
case "Name":
if was.Name() != n.Name {
onFalse(field)
return nil, false
}
case "User":
if was.User() != n.User {
onFalse(field)
return nil, false
}
case "Sharer":
if was.Sharer() != n.Sharer {
onFalse(field)
return nil, false
}
case "Key":
@ -949,6 +969,7 @@ func peerChangeDiff(was tailcfg.NodeView, n *tailcfg.Node) (_ *tailcfg.PeerChang
}
case "Machine":
if was.Machine() != n.Machine {
onFalse(field)
return nil, false
}
case "DiscoKey":
@ -957,10 +978,12 @@ func peerChangeDiff(was tailcfg.NodeView, n *tailcfg.Node) (_ *tailcfg.PeerChang
}
case "Addresses":
if !views.SliceEqual(was.Addresses(), views.SliceOf(n.Addresses)) {
onFalse(field)
return nil, false
}
case "AllowedIPs":
if !views.SliceEqual(was.AllowedIPs(), views.SliceOf(n.AllowedIPs)) {
onFalse(field)
return nil, false
}
case "Endpoints":
@ -980,13 +1003,16 @@ func peerChangeDiff(was tailcfg.NodeView, n *tailcfg.Node) (_ *tailcfg.PeerChang
continue
}
if !was.Hostinfo().Valid() || !n.Hostinfo.Valid() {
onFalse(field)
return nil, false
}
if !was.Hostinfo().Equal(n.Hostinfo) {
onFalse(field)
return nil, false
}
case "Created":
if !was.Created().Equal(n.Created) {
onFalse(field)
return nil, false
}
case "Cap":
@ -1014,10 +1040,12 @@ func peerChangeDiff(was tailcfg.NodeView, n *tailcfg.Node) (_ *tailcfg.PeerChang
}
case "Tags":
if !views.SliceEqual(was.Tags(), views.SliceOf(n.Tags)) {
onFalse(field)
return nil, false
}
case "PrimaryRoutes":
if !views.SliceEqual(was.PrimaryRoutes(), views.SliceOf(n.PrimaryRoutes)) {
onFalse(field)
return nil, false
}
case "Online":
@ -1030,22 +1058,27 @@ func peerChangeDiff(was tailcfg.NodeView, n *tailcfg.Node) (_ *tailcfg.PeerChang
}
case "MachineAuthorized":
if was.MachineAuthorized() != n.MachineAuthorized {
onFalse(field)
return nil, false
}
case "UnsignedPeerAPIOnly":
if was.UnsignedPeerAPIOnly() != n.UnsignedPeerAPIOnly {
onFalse(field)
return nil, false
}
case "IsWireGuardOnly":
if was.IsWireGuardOnly() != n.IsWireGuardOnly {
onFalse(field)
return nil, false
}
case "IsJailed":
if was.IsJailed() != n.IsJailed {
onFalse(field)
return nil, false
}
case "Expired":
if was.Expired() != n.Expired {
onFalse(field)
return nil, false
}
case "SelfNodeV4MasqAddrForThisPeer":
@ -1054,6 +1087,7 @@ func peerChangeDiff(was tailcfg.NodeView, n *tailcfg.Node) (_ *tailcfg.PeerChang
continue
}
if va, ok := va.GetOk(); !ok || vb == nil || va != *vb {
onFalse(field)
return nil, false
}
case "SelfNodeV6MasqAddrForThisPeer":
@ -1062,17 +1096,20 @@ func peerChangeDiff(was tailcfg.NodeView, n *tailcfg.Node) (_ *tailcfg.PeerChang
continue
}
if va, ok := va.GetOk(); !ok || vb == nil || va != *vb {
onFalse(field)
return nil, false
}
case "ExitNodeDNSResolvers":
va, vb := was.ExitNodeDNSResolvers(), views.SliceOfViews(n.ExitNodeDNSResolvers)
if va.Len() != vb.Len() {
onFalse(field)
return nil, false
}
for i := range va.Len() {
if !va.At(i).Equal(vb.At(i)) {
onFalse(field)
return nil, false
}
}

16
control/controlclient/map_debug.go Normal file
View File

@ -0,0 +1,16 @@
// Copyright (c) Tailscale Inc & contributors
// SPDX-License-Identifier: BSD-3-Clause
//go:build !ts_omit_debug
package controlclient
import "tailscale.com/metrics"
var patchifyMissStats = metrics.NewLabelMap("counter_patchify_miss", "why")
func init() {
patchifyMissOnFalse = func(field string) {
patchifyMissStats.Add(field, 1)
}
}

4
control/controlclient/map_test.go
View File

@ -1231,7 +1231,7 @@ func TestPeerChangeDiff(t *testing.T) {
}
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
pc, ok := peerChangeDiff(tt.a.View(), tt.b)
pc, ok := peerChangeDiff(tt.a.View(), tt.b, nil)
if tt.wantEqual {
if !ok || pc != nil {
t.Errorf("got (%p, %v); want (nil, true); pc=%v", pc, ok, logger.AsJSON(pc))
@ -1252,7 +1252,7 @@ func TestPeerChangeDiffAllocs(t *testing.T) {
a := &tailcfg.Node{ID: 1}
b := &tailcfg.Node{ID: 1}
n := testing.AllocsPerRun(10000, func() {
diff, ok := peerChangeDiff(a.View(), b)
diff, ok := peerChangeDiff(a.View(), b, nil)
if !ok || diff != nil {
t.Fatalf("unexpected result: (%s, %v)", logger.AsJSON(diff), ok)
}