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Don't double report metrics on error (#2719)

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* Don't double report metrics on error

When there is an error use a different function to report the metrics,
in case the plugin chain handled the request the metrics are already
reported.

Fixes: #2717

Signed-off-by: Miek Gieben <miek@miek.nl>

* Compile again

Signed-off-by: Miek Gieben <miek@miek.nl>
This commit is contained in:
Miek Gieben 2019-03-25 19:04:03 +00:00 • committed by GitHub
parent 9a8c301a42
commit 93f635023a
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GPG key ID: 4AEE18F83AFDEB23
2 changed files with 18 additions and 8 deletions
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18
core/dnsserver/server.go
View file

@ -205,7 +205,7 @@ func (s *Server) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg)
// The default dns.Mux checks the question section size, but we have our // The default dns.Mux checks the question section size, but we have our
// own mux here. Check if we have a question section. If not drop them here. // own mux here. Check if we have a question section. If not drop them here.
if r == nil || len(r.Question) == 0 { if r == nil || len(r.Question) == 0 {
errorFunc(s.Addr, w, r, dns.RcodeServerFailure) errorAndMetricsFunc(s.Addr, w, r, dns.RcodeServerFailure)
return return
} }
@ -215,13 +215,13 @@ func (s *Server) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg)
// need to make sure that we stay alive up here // need to make sure that we stay alive up here
if rec := recover(); rec != nil { if rec := recover(); rec != nil {
vars.Panic.Inc() vars.Panic.Inc()
errorFunc(s.Addr, w, r, dns.RcodeServerFailure) errorAndMetricsFunc(s.Addr, w, r, dns.RcodeServerFailure)
} }
}() }()
} }
if !s.classChaos && r.Question[0].Qclass != dns.ClassINET { if !s.classChaos && r.Question[0].Qclass != dns.ClassINET {
errorFunc(s.Addr, w, r, dns.RcodeRefused) errorAndMetricsFunc(s.Addr, w, r, dns.RcodeRefused)
return return
} }
@ -301,7 +301,7 @@ func (s *Server) ServeDNS(ctx context.Context, w dns.ResponseWriter, r *dns.Msg)
} }
// Still here? Error out with REFUSED. // Still here? Error out with REFUSED.
errorFunc(s.Addr, w, r, dns.RcodeRefused) errorAndMetricsFunc(s.Addr, w, r, dns.RcodeRefused)
} }
// OnStartupComplete lists the sites served by this server // OnStartupComplete lists the sites served by this server
@ -333,7 +333,16 @@ func errorFunc(server string, w dns.ResponseWriter, r *dns.Msg, rc int) {
answer := new(dns.Msg) answer := new(dns.Msg)
answer.SetRcode(r, rc) answer.SetRcode(r, rc)
state.SizeAndDo(answer)
w.WriteMsg(answer)
}
func errorAndMetricsFunc(server string, w dns.ResponseWriter, r *dns.Msg, rc int) {
state := request.Request{W: w, Req: r}
answer := new(dns.Msg)
answer.SetRcode(r, rc)
state.SizeAndDo(answer) state.SizeAndDo(answer)
vars.Report(server, state, vars.Dropped, rcode.ToString(rc), answer.Len(), time.Now()) vars.Report(server, state, vars.Dropped, rcode.ToString(rc), answer.Len(), time.Now())
@ -344,7 +353,6 @@ func errorFunc(server string, w dns.ResponseWriter, r *dns.Msg, rc int) {
const ( const (
tcp = 0 tcp = 0
udp = 1 udp = 1
maxreentries = 10
) )
// Key is the context key for the current server added to the context. // Key is the context key for the current server added to the context.

4
plugin/metrics/vars/report.go
View file

@ -8,7 +8,9 @@ import (
"github.com/miekg/dns" "github.com/miekg/dns"
) )
// Report reports the metrics data associated with request. // Report reports the metrics data associated with request. This function is exported because it is also
// called from core/dnsserver to report requests hitting the server that should not be handled and are thus
// not sent down the plugin chain.
func Report(server string, req request.Request, zone, rcode string, size int, start time.Time) { func Report(server string, req request.Request, zone, rcode string, size int, start time.Time) {
// Proto and Family. // Proto and Family.
net := req.Proto() net := req.Proto()