Merge pull request #23798 from apolcyn/raise_timeout

Raise deadline of CancelDuringAresQuery.TestHitDeadlineAndDestroyChannelDuringAresResolutionWithQueryTimeoutIsGraceful

test/cpp/naming/cancel_ares_query_test.cc

@@ -287,10 +287,17 @@ void TestCancelDuringActiveQuery(
           query_timeout_setting);
   grpc_channel_args* client_args = nullptr;
   grpc_status_code expected_status_code = GRPC_STATUS_OK;
+  gpr_timespec rpc_deadline;
   if (query_timeout_setting == NONE) {
+    // The RPC deadline should go off well before the DNS resolution
+    // timeout fires.
     expected_status_code = GRPC_STATUS_DEADLINE_EXCEEDED;
+    // use default DNS resolution timeout (which is over one minute).
     client_args = nullptr;
+    rpc_deadline = grpc_timeout_milliseconds_to_deadline(100);
   } else if (query_timeout_setting == SHORT) {
+    // The DNS resolution timeout should fire well before the
+    // RPC's deadline expires.
     expected_status_code = GRPC_STATUS_UNAVAILABLE;
     grpc_arg arg;
     arg.type = GRPC_ARG_INTEGER;
@@ -298,13 +305,21 @@ void TestCancelDuringActiveQuery(
     arg.value.integer =
         1;  // Set this shorter than the call deadline so that it goes off.
     client_args = grpc_channel_args_copy_and_add(nullptr, &arg, 1);
+    // Set the deadline high enough such that if we hit this and get
+    // a deadline exceeded status code, then we are confident that there's
+    // a bug causing cancellation of DNS resolutions to not happen in a timely
+    // manner.
+    rpc_deadline = grpc_timeout_seconds_to_deadline(10);
   } else if (query_timeout_setting == ZERO) {
+    // The RPC deadline should go off well before the DNS resolution
+    // timeout fires.
     expected_status_code = GRPC_STATUS_DEADLINE_EXCEEDED;
     grpc_arg arg;
     arg.type = GRPC_ARG_INTEGER;
     arg.key = const_cast<char*>(GRPC_ARG_DNS_ARES_QUERY_TIMEOUT_MS);
     arg.value.integer = 0;  // Set this to zero to disable query timeouts.
     client_args = grpc_channel_args_copy_and_add(nullptr, &arg, 1);
+    rpc_deadline = grpc_timeout_milliseconds_to_deadline(100);
   } else {
     abort();
   }
@@ -312,10 +327,9 @@ void TestCancelDuringActiveQuery(
       grpc_insecure_channel_create(client_target.c_str(), client_args, nullptr);
   grpc_completion_queue* cq = grpc_completion_queue_create_for_next(nullptr);
   cq_verifier* cqv = cq_verifier_create(cq);
-  gpr_timespec deadline = grpc_timeout_milliseconds_to_deadline(100);
   grpc_call* call = grpc_channel_create_call(
       client, nullptr, GRPC_PROPAGATE_DEFAULTS, cq,
-      grpc_slice_from_static_string("/foo"), nullptr, deadline, nullptr);
+      grpc_slice_from_static_string("/foo"), nullptr, rpc_deadline, nullptr);
   GPR_ASSERT(call);
   grpc_metadata_array initial_metadata_recv;
   grpc_metadata_array trailing_metadata_recv;