do not try to recover sender errors that are client errors

http_mgmt.go

@@ -136,7 +136,7 @@ func (em *entityManager) Execute(ctx context.Context, method string, entityPath
 	if err != nil {
 		log.For(ctx).Error(err)
 	}
-	
+
 	if res != nil {
 		applyResponseInfo(span, res)
 	}

hub_test.go

@@ -258,6 +258,7 @@ func (suite *eventHubSuite) TestSasToken() {
 func (suite *eventHubSuite) TestPartitioned() {
 	tests := map[string]func(context.Context, *testing.T, *Hub, string){
 		"TestSend":                testBasicSend,
+		"TestSendTooBig":          testSendTooBig,
 		"TestSendAndReceive":      testBasicSendAndReceive,
 		"TestBatchSendAndReceive": testBatchSendAndReceive,
 	}
@@ -281,7 +282,15 @@ func (suite *eventHubSuite) TestPartitioned() {
 
 func testBasicSend(ctx context.Context, t *testing.T, client *Hub, _ string) {
 	err := client.Send(ctx, NewEventFromString("Hello!"))
-	assert.Nil(t, err)
+	assert.NoError(t, err)
+}
+
+func testSendTooBig(ctx context.Context, t *testing.T, client *Hub, _ string) {
+	data := make([]byte, 256*1024)
+	_, _ = rand.Read(data)
+	event := NewEvent(data)
+	err := client.Send(ctx, event)
+	assert.Error(t, err)
 }
 
 func testBatchSendAndReceive(ctx context.Context, t *testing.T, client *Hub, partitionID string) {

sender.go

@@ -25,6 +25,7 @@ package eventhub
 import (
 	"context"
 	"fmt"
+	"math/rand"
 	"time"
 
 	"github.com/Azure/azure-amqp-common-go"
@@ -138,6 +139,7 @@ func (s *sender) trySend(ctx context.Context, evt eventer) error {
 			return ctx.Err()
 		default:
 			// try to recover the connection
+			count := 0
 			_, retryErr := common.Retry(10, 5*time.Second, func() (interface{}, error) {
 				sp, ctx := s.startProducerSpanFromContext(ctx, "eh.sender.trySend.tryRecover")
 				defer sp.Finish()
@@ -150,24 +152,31 @@ func (s *sender) trySend(ctx context.Context, evt eventer) error {
 						amqpErr.Condition == "com.microsoft:timeout" {
 
 						log.For(ctx).Debug(amqpErr.Error())
-						time.Sleep(2 * time.Second) // delay send for a moment due to server busy
-						return nil, common.Retryable(amqpErr.Error())
-					}
-				}
+						time.Sleep(time.Duration(2*rand.Intn(1000)/1000) * time.Second) // delay send for a moment due to server busy
 
-				err := s.Recover(ctx)
-				select {
-				case <-ctx.Done():
-					// context is done, so return
-					return nil, ctx.Err()
-				default:
-					if err != nil {
-						log.For(ctx).Error(err)
-						return nil, common.Retryable(err.Error())
+						if count >= 1 {
+							// we've been here before, try to recover the connection
+							err := s.Recover(ctx)
+							select {
+							case <-ctx.Done():
+								// context is done, so return
+								return nil, ctx.Err()
+							default:
+								if err != nil {
+									log.For(ctx).Error(err)
+									return nil, common.Retryable(err.Error())
+								}
+								log.For(ctx).Debug("recovered the connection")
+								return nil, nil
+							}
+						}
+
+						count++
+						// connection should still be good
+						return nil, nil
 					}
-					log.For(ctx).Debug("recovered the connection")
-					return nil, nil
 				}
+				return nil, err
 			})
 
 			if retryErr != nil {