sockstats: refactor validation to be opt-in

Followup to #7499 to make validation a separate function (
GetWithValidation vs. Get). This way callers that don't need it don't
pay the cost of a syscall per active TCP socket.

Also clears the conn on close, so that we don't double-count the stats.

Also more consistently uses Go doc comments for the exported API of the
sockstats package.

Updates tailscale/corp#9230
Updates #3363

Signed-off-by: Mihai Parparita <mihai@tailscale.com>
This commit is contained in:
Mihai Parparita 2023-03-09 11:40:07 -08:00 committed by Mihai Parparita
parent ea81bffdeb
commit b64d78d58f
4 changed files with 75 additions and 25 deletions

View File

@ -865,7 +865,7 @@ func (h *peerAPIHandler) handleServeSockStats(w http.ResponseWriter, r *http.Req
w.Header().Set("Content-Type", "text/html; charset=utf-8")
fmt.Fprintln(w, "<!DOCTYPE html><h1>Socket Stats</h1>")
stats := sockstats.Get()
stats, validation := sockstats.GetWithValidation()
if stats == nil {
fmt.Fprintln(w, "No socket stats available")
return
@ -914,12 +914,12 @@ func (h *peerAPIHandler) handleServeSockStats(w http.ResponseWriter, r *http.Req
rxTotalByInterface[iface] += stat.RxBytesByInterface[iface]
}
if stat.ValidationRxBytes > 0 || stat.ValidationTxBytes > 0 {
if validationStat, ok := validation.Stats[label]; ok && (validationStat.RxBytes > 0 || validationStat.TxBytes > 0) {
fmt.Fprintf(w, "<td>Tx=%d (%+d) Rx=%d (%+d)</td>",
stat.ValidationTxBytes,
int64(stat.ValidationTxBytes)-int64(stat.TxBytes),
stat.ValidationRxBytes,
int64(stat.ValidationRxBytes)-int64(stat.RxBytes))
validationStat.TxBytes,
int64(validationStat.TxBytes)-int64(stat.TxBytes),
validationStat.RxBytes,
int64(validationStat.RxBytes)-int64(stat.RxBytes))
} else {
fmt.Fprintln(w, "<td></td>")
}

View File

@ -14,11 +14,25 @@ import (
"tailscale.com/net/interfaces"
)
// SockStats contains statistics for sockets instrumented with the
// WithSockStats() function, along with the interfaces that we have
// per-interface statistics for.
type SockStats struct {
Stats map[Label]SockStat
Interfaces []string
}
// SockStat contains the sent and received bytes for a socket instrumented with
// the WithSockStats() function. The bytes are also broken down by interface,
// though this may be a subset of the total if interfaces were added after the
// instrumented socket was created.
type SockStat struct {
TxBytes uint64
RxBytes uint64
TxBytesByInterface map[string]uint64
RxBytesByInterface map[string]uint64
}
// Label is an identifier for a socket that stats are collected for. A finite
// set of values that may be used to label a socket to encourage grouping and
// to make storage more efficient.
@ -41,25 +55,38 @@ const (
LabelMagicsockConnUDP6 Label = 9 // wgengine/magicsock/magicsock.go
)
type SockStat struct {
TxBytes uint64
RxBytes uint64
TxBytesByInterface map[string]uint64
RxBytesByInterface map[string]uint64
// NOCOMMIT
ValidationTxBytes uint64
ValidationRxBytes uint64
}
// WithSockStats instruments a context so that sockets created with it will
// have their statistics collected.
func WithSockStats(ctx context.Context, label Label) context.Context {
return withSockStats(ctx, label)
}
// Get returns the current socket statistics.
func Get() *SockStats {
return get()
}
// ValidationSockStats contains external validation numbers for sockets
// instrumented with WithSockStats. It may be a subset of the all sockets,
// depending on what externa measurement mechanisms the platform supports.
type ValidationSockStats struct {
Stats map[Label]ValidationSockStat
}
// ValidationSockStat contains the validation bytes for a socket instrumented
// with WithSockStats.
type ValidationSockStat struct {
TxBytes uint64
RxBytes uint64
}
// GetWithValidation is a variant of GetWith that returns both the current stats
// and external validation numbers for the stats. It is more expensive than
// Get and should be used in debug interfaces only.
func GetWithValidation() (*SockStats, *ValidationSockStats) {
return get(), getValidation()
}
// LinkMonitor is the interface for the parts of wgengine/mointor's Mon that we
// need, to avoid the dependency.
type LinkMonitor interface {
@ -67,6 +94,8 @@ type LinkMonitor interface {
RegisterChangeCallback(interfaces.ChangeFunc) (unregister func())
}
// SetLinkMonitor configures the sockstats package to monitor the active
// interface, so that per-interface stats can be collected.
func SetLinkMonitor(lm LinkMonitor) {
setLinkMonitor(lm)
}

View File

@ -17,5 +17,9 @@ func get() *SockStats {
return nil
}
func getValidation() *ValidationSockStats {
return nil
}
func setLinkMonitor(lm LinkMonitor) {
}

View File

@ -96,6 +96,7 @@ func withSockStats(ctx context.Context, label Label) context.Context {
tx, rx := tcpConnStats(c)
counters.validationTxBytes.Add(tx)
counters.validationRxBytes.Add(rx)
counters.validationConn.Store(nil)
}
// Don't bother adding these hooks if we can't get stats that they end up
@ -167,14 +168,6 @@ func get() *SockStats {
RxBytes: counters.rxBytes.Load(),
TxBytesByInterface: make(map[string]uint64),
RxBytesByInterface: make(map[string]uint64),
ValidationTxBytes: counters.validationTxBytes.Load(),
ValidationRxBytes: counters.validationRxBytes.Load(),
}
if c := counters.validationConn.Load(); c != nil && tcpConnStats != nil {
tx, rx := tcpConnStats(*c)
s.ValidationTxBytes += tx
s.ValidationRxBytes += rx
}
for iface, a := range counters.rxBytesByInterface {
ifName := sockStats.knownInterfaces[iface]
@ -190,6 +183,30 @@ func get() *SockStats {
return r
}
func getValidation() *ValidationSockStats {
sockStats.mu.Lock()
defer sockStats.mu.Unlock()
r := &ValidationSockStats{
Stats: make(map[Label]ValidationSockStat),
}
for label, counters := range sockStats.countersByLabel {
s := ValidationSockStat{
TxBytes: counters.validationTxBytes.Load(),
RxBytes: counters.validationRxBytes.Load(),
}
if c := counters.validationConn.Load(); c != nil && tcpConnStats != nil {
tx, rx := tcpConnStats(*c)
s.TxBytes += tx
s.RxBytes += rx
}
r.Stats[label] = s
}
return r
}
func setLinkMonitor(lm LinkMonitor) {
sockStats.mu.Lock()
defer sockStats.mu.Unlock()