Fix error metric on timeout.

go.mod

@@ -7,6 +7,7 @@ require (
 	github.com/davecgh/go-spew v1.1.1
 	github.com/grpc-ecosystem/grpc-gateway/v2 v2.11.3
 	github.com/hashicorp/memberlist v0.5.0
+	github.com/mailgun/errors v0.1.5
 	github.com/mailgun/holster/v4 v4.14.2
 	github.com/miekg/dns v1.1.50
 	github.com/pkg/errors v0.9.1

go.sum

@@ -305,6 +305,8 @@ github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
 github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
+github.com/mailgun/errors v0.1.5 h1:riRpZqfUKTdc8saXvoEg2tYkbRyZESU1KvQ3UxPbdus=
+github.com/mailgun/errors v0.1.5/go.mod h1:lw+Nh4r/aoUTz6uK915FdfZJo3yq60gPiflFHNpK4NQ=
 github.com/mailgun/holster/v4 v4.14.2 h1:wBS+IufPnQM8EBgQtLf7ywuUmmAnaEdRujul/l7xWY4=
 github.com/mailgun/holster/v4 v4.14.2/go.mod h1:0Gc8+xqL3ElCsceOt7ySj1J3j9s3WLBJaV07yeE61y4=
 github.com/mailru/easyjson v0.0.0-20190614124828-94de47d64c63/go.mod h1:C1wdFJiN94OJF2b5HbByQZoLdCWB1Yqtg26g4irojpc=

gubernator.go

@@ -23,8 +23,8 @@ import (
 	"sync"
 	"sync/atomic"
 
+	"github.com/mailgun/errors"
 	"github.com/mailgun/holster/v4/ctxutil"
-	"github.com/mailgun/holster/v4/errors"
 	"github.com/mailgun/holster/v4/setter"
 	"github.com/mailgun/holster/v4/syncutil"
 	"github.com/mailgun/holster/v4/tracing"
@@ -763,14 +763,5 @@ func countError(err error, defaultType string) {
 }
 
 func isDeadlineExceeded(err error) bool {
-	for {
-		if err == nil {
-			return false
-		}
-		if errors.Is(err, context.DeadlineExceeded) {
-			return true
-		}
-
-		err = errors.Unwrap(err)
-	}
+	return errors.As(err, context.DeadlineExceeded)
 }