TheArchive/tailscale
1
0
Fork 0
mirror of https://github.com/tailscale/tailscale.git synced 2025-01-05 23:07:44 +00:00
Code Issues Packages Projects Releases Wiki Activity

derp: add some guardrails for derpReason metrics getting out of sync

Browse Source 
The derp metrics got out of sync in 74eb99aed17539 (2023-03).

They were fixed in 0380cbc90d6 (2024-05).

This adds some further guardrails (atop the previous fix) to make sure
they don't get out of sync again.

Updates #12288

Change-Id: I809061a81f8ff92f45054d0253bc13871fc71634
Signed-off-by: Brad Fitzpatrick <bradfitz@tailscale.com>
This commit is contained in:
Brad Fitzpatrick 2024-05-31 08:06:14 -07:00 committed by Brad Fitzpatrick
parent 7e357e1636
commit f227083539
2 changed files with 27 additions and 11 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

33
derp/derp_server.go
View File

@ -330,21 +330,35 @@ func NewServer(privateKey key.NodePrivate, logf logger.Logf) *Server {
s.packetsRecvDisco = s.packetsRecvByKind.Get("disco")
s.packetsRecvOther = s.packetsRecvByKind.Get("other")
s.packetsDroppedReasonCounters = []*expvar.Int{
dropReasonUnknownDest: s.packetsDroppedReason.Get("unknown_dest"),
dropReasonUnknownDestOnFwd: s.packetsDroppedReason.Get("unknown_dest_on_fwd"),
dropReasonGoneDisconnected: s.packetsDroppedReason.Get("gone_disconnected"),
dropReasonQueueHead: s.packetsDroppedReason.Get("queue_head"),
dropReasonQueueTail: s.packetsDroppedReason.Get("queue_tail"),
dropReasonWriteError: s.packetsDroppedReason.Get("write_error"),
dropReasonDupClient: s.packetsDroppedReason.Get("dup_client"),
}
s.packetsDroppedReasonCounters = s.genPacketsDroppedReasonCounters()
s.packetsDroppedTypeDisco = s.packetsDroppedType.Get("disco")
s.packetsDroppedTypeOther = s.packetsDroppedType.Get("other")
return s
}
func (s *Server) genPacketsDroppedReasonCounters() []*expvar.Int {
getMetric := s.packetsDroppedReason.Get
ret := []*expvar.Int{
dropReasonUnknownDest: getMetric("unknown_dest"),
dropReasonUnknownDestOnFwd: getMetric("unknown_dest_on_fwd"),
dropReasonGoneDisconnected: getMetric("gone_disconnected"),
dropReasonQueueHead: getMetric("queue_head"),
dropReasonQueueTail: getMetric("queue_tail"),
dropReasonWriteError: getMetric("write_error"),
dropReasonDupClient: getMetric("dup_client"),
}
if len(ret) != int(numDropReasons) {
panic("dropReason metrics out of sync")
}
for i := range numDropReasons {
if ret[i] == nil {
panic("dropReason metrics out of sync")
}
}
return ret
}
// SetMesh sets the pre-shared key that regional DERP servers used to mesh
// amongst themselves.
//
@ -1049,6 +1063,7 @@ func (c *sclient) debugLogf(format string, v ...any) {
dropReasonQueueTail // destination queue is full, dropped packet at queue tail
dropReasonWriteError // OS write() failed
dropReasonDupClient // the public key is connected 2+ times (active/active, fighting)
numDropReasons // unused; keep last
)
func (s *Server) recordDrop(packetBytes []byte, srcKey, dstKey key.NodePublic, reason dropReason) {

5
derp/dropreason_string.go
View File

@ -18,11 +18,12 @@ func _() {
_ = x[dropReasonQueueTail-4]
_ = x[dropReasonWriteError-5]
_ = x[dropReasonDupClient-6]
_ = x[numDropReasons-7]
}
const _dropReason_name = "UnknownDestUnknownDestOnFwdGoneDisconnectedQueueHeadQueueTailWriteErrorDupClient"
const _dropReason_name = "UnknownDestUnknownDestOnFwdGoneDisconnectedQueueHeadQueueTailWriteErrorDupClientnumDropReasons"
var _dropReason_index = [...]uint8{0, 11, 27, 43, 52, 61, 71, 80}
var _dropReason_index = [...]uint8{0, 11, 27, 43, 52, 61, 71, 80, 94}
func (i dropReason) String() string {
if i < 0 || i >= dropReason(len(_dropReason_index)-1) {