1 files changed, 13 insertions, 30 deletions
diff --git a/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go b/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go
index 03825bbe7..304235566 100644
--- a/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go
+++ b/vendor/google.golang.org/grpc/internal/resolver/dns/dns_resolver.go
@@ -34,7 +34,6 @@ import (
 
 	grpclbstate "google.golang.org/grpc/balancer/grpclb/state"
 	"google.golang.org/grpc/grpclog"
-	"google.golang.org/grpc/internal/backoff"
 	"google.golang.org/grpc/internal/envconfig"
 	"google.golang.org/grpc/internal/grpcrand"
 	"google.golang.org/grpc/resolver"
@@ -47,13 +46,6 @@ var EnableSRVLookups = false
 
 var logger = grpclog.Component("dns")
 
-// Globals to stub out in tests. TODO: Perhaps these two can be combined into a
-// single variable for testing the resolver?
-var (
-	newTimer           = time.NewTimer
-	newTimerDNSResRate = time.NewTimer
-)
-
 func init() {
 	resolver.Register(NewBuilder())
 }
@@ -151,6 +143,7 @@ func (b *dnsBuilder) Build(target resolver.Target, cc resolver.ClientConn, opts
 
 	d.wg.Add(1)
 	go d.watcher()
+	d.ResolveNow(resolver.ResolveNowOptions{})
 	return d, nil
 }
 
@@ -208,38 +201,28 @@ func (d *dnsResolver) Close() {
 
 func (d *dnsResolver) watcher() {
 	defer d.wg.Done()
-	backoffIndex := 1
 	for {
+		select {
+		case <-d.ctx.Done():
+			return
+		case <-d.rn:
+		}
+
 		state, err := d.lookup()
 		if err != nil {
-			// Report error to the underlying grpc.ClientConn.
 			d.cc.ReportError(err)
 		} else {
-			err = d.cc.UpdateState(*state)
+			d.cc.UpdateState(*state)
 		}
 
-		var timer *time.Timer
-		if err == nil {
-			// Success resolving, wait for the next ResolveNow. However, also wait 30 seconds at the very least
-			// to prevent constantly re-resolving.
-			backoffIndex = 1
-			timer = newTimerDNSResRate(minDNSResRate)
-			select {
-			case <-d.ctx.Done():
-				timer.Stop()
-				return
-			case <-d.rn:
-			}
-		} else {
-			// Poll on an error found in DNS Resolver or an error received from ClientConn.
-			timer = newTimer(backoff.DefaultExponential.Backoff(backoffIndex))
-			backoffIndex++
-		}
+		// Sleep to prevent excessive re-resolutions. Incoming resolution requests
+		// will be queued in d.rn.
+		t := time.NewTimer(minDNSResRate)
 		select {
+		case <-t.C:
 		case <-d.ctx.Done():
-			timer.Stop()
+			t.Stop()
 			return
-		case <-timer.C:
 		}
 	}
 }