Fix UpdatesTest.UpdateBalancersDeadUpdate expectation

test/cpp/end2end/grpclb_end2end_test.cc

@@ -353,11 +353,6 @@ class GrpclbEnd2endTest : public ::testing::Test {
           "balancer", server_host_, balancers_.back().get()));
     }
     ResetStub();
-    std::vector<AddressData> addresses;
-    for (size_t i = 0; i < balancer_servers_.size(); ++i) {
-      addresses.emplace_back(AddressData{balancer_servers_[i].port_, true, ""});
-    }
-    SetNextResolution(addresses);
   }
 
   void TearDown() override {
@@ -370,6 +365,14 @@ class GrpclbEnd2endTest : public ::testing::Test {
     grpc_fake_resolver_response_generator_unref(response_generator_);
   }
 
+  void SetNextResolutionAllBalancers() {
+    std::vector<AddressData> addresses;
+    for (size_t i = 0; i < balancer_servers_.size(); ++i) {
+      addresses.emplace_back(AddressData{balancer_servers_[i].port_, true, ""});
+    }
+    SetNextResolution(addresses);
+  }
+
   void ResetStub(int fallback_timeout = 0) {
     ChannelArguments args;
     args.SetGrpclbFallbackTimeout(fallback_timeout);
@@ -581,6 +584,7 @@ class SingleBalancerTest : public GrpclbEnd2endTest {
 };
 
 TEST_F(SingleBalancerTest, Vanilla) {
+  SetNextResolutionAllBalancers();
   const size_t kNumRpcsPerAddress = 100;
   ScheduleResponseForBalancer(
       0, BalancerServiceImpl::BuildResponseForBackends(GetBackendPorts(), {}),
@@ -608,6 +612,7 @@ TEST_F(SingleBalancerTest, Vanilla) {
 }
 
 TEST_F(SingleBalancerTest, InitiallyEmptyServerlist) {
+  SetNextResolutionAllBalancers();
   const int kServerlistDelayMs = 500 * grpc_test_slowdown_factor();
   const int kCallDeadlineMs = 1000 * grpc_test_slowdown_factor();
 
@@ -645,6 +650,7 @@ TEST_F(SingleBalancerTest, InitiallyEmptyServerlist) {
 }
 
 TEST_F(SingleBalancerTest, Fallback) {
+  SetNextResolutionAllBalancers();
   const int kFallbackTimeoutMs = 200 * grpc_test_slowdown_factor();
   const int kServerlistDelayMs = 500 * grpc_test_slowdown_factor();
   const size_t kNumBackendInResolution = backends_.size() / 2;
@@ -711,6 +717,7 @@ TEST_F(SingleBalancerTest, Fallback) {
 }
 
 TEST_F(SingleBalancerTest, FallbackUpdate) {
+  SetNextResolutionAllBalancers();
   const int kFallbackTimeoutMs = 200 * grpc_test_slowdown_factor();
   const int kServerlistDelayMs = 500 * grpc_test_slowdown_factor();
   const size_t kNumBackendInResolution = backends_.size() / 3;
@@ -818,6 +825,7 @@ TEST_F(SingleBalancerTest, FallbackUpdate) {
 }
 
 TEST_F(SingleBalancerTest, BackendsRestart) {
+  SetNextResolutionAllBalancers();
   const size_t kNumRpcsPerAddress = 100;
   ScheduleResponseForBalancer(
       0, BalancerServiceImpl::BuildResponseForBackends(GetBackendPorts(), {}),
@@ -857,6 +865,7 @@ class UpdatesTest : public GrpclbEnd2endTest {
 };
 
 TEST_F(UpdatesTest, UpdateBalancers) {
+  SetNextResolutionAllBalancers();
   const std::vector<int> first_backend{GetBackendPorts()[0]};
   const std::vector<int> second_backend{GetBackendPorts()[1]};
   ScheduleResponseForBalancer(
@@ -919,6 +928,7 @@ TEST_F(UpdatesTest, UpdateBalancers) {
 // verify that the LB channel inside grpclb keeps the initial connection (which
 // by definition is also present in the update).
 TEST_F(UpdatesTest, UpdateBalancersRepeated) {
+  SetNextResolutionAllBalancers();
   const std::vector<int> first_backend{GetBackendPorts()[0]};
   const std::vector<int> second_backend{GetBackendPorts()[0]};
 
@@ -989,6 +999,9 @@ TEST_F(UpdatesTest, UpdateBalancersRepeated) {
 }
 
 TEST_F(UpdatesTest, UpdateBalancersDeadUpdate) {
+  std::vector<AddressData> addresses;
+  addresses.emplace_back(AddressData{balancer_servers_[0].port_, true, ""});
+  SetNextResolution(addresses);
   const std::vector<int> first_backend{GetBackendPorts()[0]};
   const std::vector<int> second_backend{GetBackendPorts()[1]};
 
@@ -1030,7 +1043,7 @@ TEST_F(UpdatesTest, UpdateBalancersDeadUpdate) {
   EXPECT_EQ(0U, balancer_servers_[2].service_->request_count());
   EXPECT_EQ(0U, balancer_servers_[2].service_->response_count());
 
-  std::vector<AddressData> addresses;
+  addresses.clear();
   addresses.emplace_back(AddressData{balancer_servers_[1].port_, true, ""});
   gpr_log(GPR_INFO, "========= ABOUT TO UPDATE 1 ==========");
   SetNextResolution(addresses);
@@ -1055,8 +1068,14 @@ TEST_F(UpdatesTest, UpdateBalancersDeadUpdate) {
   balancers_[2]->NotifyDoneWithServerlists();
   EXPECT_EQ(1U, balancer_servers_[0].service_->request_count());
   EXPECT_EQ(1U, balancer_servers_[0].service_->response_count());
-  EXPECT_EQ(1U, balancer_servers_[1].service_->request_count());
-  EXPECT_EQ(1U, balancer_servers_[1].service_->response_count());
+  // The second balancer, published as part of the first update, may end up
+  // getting two requests (that is, 1 <= #req <= 2) if the LB call retry timer
+  // firing races with the arrival of the update containing the second
+  // balancer.
+  EXPECT_GE(balancer_servers_[1].service_->request_count(), 1U);
+  EXPECT_GE(balancer_servers_[1].service_->response_count(), 1U);
+  EXPECT_LE(balancer_servers_[1].service_->request_count(), 2U);
+  EXPECT_LE(balancer_servers_[1].service_->response_count(), 2U);
   EXPECT_EQ(0U, balancer_servers_[2].service_->request_count());
   EXPECT_EQ(0U, balancer_servers_[2].service_->response_count());
   // Check LB policy name for the channel.
@@ -1064,6 +1083,7 @@ TEST_F(UpdatesTest, UpdateBalancersDeadUpdate) {
 }
 
 TEST_F(SingleBalancerTest, Drop) {
+  SetNextResolutionAllBalancers();
   const size_t kNumRpcsPerAddress = 100;
   const int num_of_drop_by_rate_limiting_addresses = 1;
   const int num_of_drop_by_load_balancing_addresses = 2;
@@ -1107,6 +1127,7 @@ TEST_F(SingleBalancerTest, Drop) {
 }
 
 TEST_F(SingleBalancerTest, DropAllFirst) {
+  SetNextResolutionAllBalancers();
   // All registered addresses are marked as "drop".
   const int num_of_drop_by_rate_limiting_addresses = 1;
   const int num_of_drop_by_load_balancing_addresses = 1;
@@ -1122,6 +1143,7 @@ TEST_F(SingleBalancerTest, DropAllFirst) {
 }
 
 TEST_F(SingleBalancerTest, DropAll) {
+  SetNextResolutionAllBalancers();
   ScheduleResponseForBalancer(
       0, BalancerServiceImpl::BuildResponseForBackends(GetBackendPorts(), {}),
       0);
@@ -1152,6 +1174,7 @@ class SingleBalancerWithClientLoadReportingTest : public GrpclbEnd2endTest {
 };
 
 TEST_F(SingleBalancerWithClientLoadReportingTest, Vanilla) {
+  SetNextResolutionAllBalancers();
   const size_t kNumRpcsPerAddress = 100;
   ScheduleResponseForBalancer(
       0, BalancerServiceImpl::BuildResponseForBackends(GetBackendPorts(), {}),
@@ -1186,6 +1209,7 @@ TEST_F(SingleBalancerWithClientLoadReportingTest, Vanilla) {
 }
 
 TEST_F(SingleBalancerWithClientLoadReportingTest, Drop) {
+  SetNextResolutionAllBalancers();
   const size_t kNumRpcsPerAddress = 3;
   const int num_of_drop_by_rate_limiting_addresses = 2;
   const int num_of_drop_by_load_balancing_addresses = 1;