Don't invalid region when first round cause by deadlineErr when using…

… config timeout tikv#1177

Signed-off-by: crazycs520 <[email protected]>

internal/locate/region_request.go

@@ -785,6 +785,12 @@ func (state *accessFollower) next(bo *retry.Backoffer, selector *replicaSelector
 				}
 				return nil, stateChanged{}
 			}
+			for _, r := range selector.replicas {
+				if r.deadlineErrUsingConfTimeout {
+					// when meet deadline exceeded error, do fast retry without invalidate region cache.
+					return nil, nil
+				}
+			}
 			metrics.TiKVReplicaSelectorFailureCounter.WithLabelValues("exhausted").Inc()
 			selector.invalidateRegion()
 			return nil, nil

internal/locate/replica_selector_test.go

@@ -184,6 +184,28 @@ func TestReplicaReadAccessPathByCase(t *testing.T) {
 	}
 	s.True(s.runCaseAndCompare(ca))
 
+	// Don't invalid region in accessFollower, since leader meets deadlineExceededErr.
+	ca = replicaSelectorAccessPathCase{
+		reqType:   tikvrpc.CmdGet,
+		readType:  kv.ReplicaReadMixed,
+		staleRead: false,
+		timeout:   time.Second,
+		label:     nil,
+		accessErr: []RegionErrorType{ServerIsBusyErr, ServerIsBusyErr, DeadLineExceededErr},
+		expect: &accessPathResult{
+			accessPath: []string{
+				"{addr: store1, replica-read: true, stale-read: false}",
+				"{addr: store2, replica-read: true, stale-read: false}",
+				"{addr: store3, replica-read: true, stale-read: false}"},
+			respErr:         "",
+			respRegionError: fakeEpochNotMatch,
+			backoffCnt:      0,
+			backoffDetail:   []string{},
+			regionIsValid:   true,
+		},
+	}
+	s.True(s.runCaseAndCompare(ca))
+
 	// Don't invalid region in tryFollowers, since leader meets deadlineExceededErr.
 	ca = replicaSelectorAccessPathCase{
 		reqType:   tikvrpc.CmdGet,