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cmd/derper, derp: add some more varz and consistency check handler

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I'm trying to hunt down a slow drift in numbers not agreeing.
This commit is contained in:
Brad Fitzpatrick 2020-06-23 13:59:48 -07:00
parent c2682553ff
commit b87396b5d9
2 changed files with 57 additions and 2 deletions
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10
cmd/derper/derper.go
View File

@ -204,6 +204,15 @@ func main() {
func debugHandler(s *derp.Server) http.Handler {
return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
if r.RequestURI == "/debug/check" {
err := s.ConsistencyCheck()
if err != nil {
http.Error(w, err.Error(), 500)
} else {
io.WriteString(w, "derp.Server ConsistencyCheck okay")
}
return
}
f := func(format string, args ...interface{}) { fmt.Fprintf(w, format, args...) }
f(`<html><body>
<h1>DERP debug</h1>
@ -218,6 +227,7 @@ func debugHandler(s *derp.Server) http.Handler {
<li><a href="/debug/pprof/">/debug/pprof/</a></li>
<li><a href="/debug/pprof/goroutine?debug=1">/debug/pprof/goroutine</a> (collapsed)</li>
<li><a href="/debug/pprof/goroutine?debug=2">/debug/pprof/goroutine</a> (full)</li>
<li><a href="/debug/check">/debug/check</a> internal consistency check</li>
<ul>
</html>
`)

49
derp/derp_server.go
View File

@ -20,6 +20,7 @@
"os"
"runtime"
"strconv"
"strings"
"sync"
"time"
@ -72,6 +73,7 @@ type Server struct {
homeMovesOut expvar.Int // established clients announce home server moves out
multiForwarderCreated expvar.Int
multiForwarderDeleted expvar.Int
removePktForwardOther expvar.Int
mu sync.Mutex
closed bool
@ -81,8 +83,9 @@ type Server struct {
watchers map[*sclient]bool // mesh peer -> true
// clientsMesh tracks all clients in the cluster, both locally
// and to mesh peers. If the value is nil, that means the
// peer is only remote (and thus in the clients Map). If the
// value is non-nil, it's only remote.
// peer is only local (and thus in the clients Map, but not
// remote). If the value is non-nil, it's remote (+ maybe also
// local).
clientsMesh map[key.Public]PacketForwarder
// sentTo tracks which peers have sent to which other peers,
// and at which connection number. This isn't on sclient
@ -1067,6 +1070,7 @@ func (s *Server) RemovePacketForwarder(dst key.Public, fwd PacketForwarder) {
return
}
if v != fwd {
s.removePktForwardOther.Add(1)
// Delete of an entry that wasn't in the
// map. Harmless, so ignore.
// (This might happen if a user is moving around
@ -1131,6 +1135,7 @@ func (s *Server) ExpVar() expvar.Var {
m.Set("gauge_current_connnections", &s.curClients)
m.Set("gauge_current_home_connnections", &s.curHomeClients)
m.Set("gauge_clients_total", expvar.Func(func() interface{} { return len(s.clientsMesh) }))
m.Set("gauge_clients_local", expvar.Func(func() interface{} { return len(s.clients) }))
m.Set("gauge_clients_remote", expvar.Func(func() interface{} { return len(s.clientsMesh) - len(s.clients) }))
m.Set("accepts", &s.accepts)
m.Set("clients_replaced", &s.clientsReplaced)
@ -1148,5 +1153,45 @@ func (s *Server) ExpVar() expvar.Var {
m.Set("packets_forwarded_in", &s.packetsForwardedIn)
m.Set("multiforwarder_created", &s.multiForwarderCreated)
m.Set("multiforwarder_deleted", &s.multiForwarderDeleted)
m.Set("packet_forwarder_delete_other_value", &s.removePktForwardOther)
return m
}
func (s *Server) ConsistencyCheck() error {
s.mu.Lock()
defer s.mu.Unlock()
var errs []string
var nilMeshNotInClient int
for k, f := range s.clientsMesh {
if f == nil {
if _, ok := s.clients[k]; !ok {
nilMeshNotInClient++
}
}
}
if nilMeshNotInClient != 0 {
errs = append(errs, fmt.Sprintf("%d s.clientsMesh keys not in s.clients", nilMeshNotInClient))
}
var clientNotInMesh int
for k := range s.clients {
if _, ok := s.clientsMesh[k]; !ok {
clientNotInMesh++
}
}
if clientNotInMesh != 0 {
errs = append(errs, fmt.Sprintf("%d s.clients keys not in s.clientsMesh", clientNotInMesh))
}
if s.curClients.Value() != int64(len(s.clients)) {
errs = append(errs, fmt.Sprintf("expvar connections = %d != clients map says of %d",
s.curClients.Value(),
len(s.clients)))
}
if len(errs) == 0 {
return nil
}
return errors.New(strings.Join(errs, ", "))
}