test/core/transport/chttp2/too_many_pings_test.cc

   1 /*
   2  *
   3  * Copyright 2020 gRPC authors.
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *     http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  *
  17  */
  18
  19 #include <grpc/support/port_platform.h>
  20
  21 #include <gmock/gmock.h>
  22 #include <stdlib.h>
  23 #include <string.h>
  24 #include <functional>
  25 #include <set>
  26 #include <thread>
  27
  28 #include "absl/strings/str_cat.h"
  29
  30 #include <grpc/grpc.h>
  31 #include <grpc/grpc_security.h>
  32 #include <grpc/impl/codegen/grpc_types.h>
  33 #include <grpc/slice.h>
  34 #include <grpc/support/alloc.h>
  35 #include <grpc/support/log.h>
  36 #include <grpc/support/string_util.h>
  37 #include <grpc/support/time.h>
  38
  39 #include <grpcpp/impl/codegen/service_type.h>
  40 #include <grpcpp/server_builder.h>
  41
  42 #include "src/core/ext/filters/client_channel/resolver/fake/fake_resolver.h"
  43 #include "src/core/lib/gpr/useful.h"
  44 #include "src/core/lib/gprpp/host_port.h"
  45 #include "src/core/lib/gprpp/thd.h"
  46 #include "src/core/lib/iomgr/error.h"
  47 #include "src/core/lib/iomgr/parse_address.h"
  48 #include "src/core/lib/security/credentials/alts/alts_credentials.h"
  49 #include "src/core/lib/security/credentials/credentials.h"
  50 #include "src/core/lib/security/security_connector/alts/alts_security_connector.h"
  51 #include "src/core/lib/slice/slice_string_helpers.h"
  52 #include "src/core/lib/surface/channel.h"
  53
  54 #include "test/core/util/memory_counters.h"
  55 #include "test/core/util/port.h"
  56 #include "test/core/util/test_config.h"
  57
  58 #include "test/core/end2end/cq_verifier.h"
  59
  60 namespace {
  61
  62 void* tag(int i) { return (void*)static_cast<intptr_t>(i); }
  63
  64 // Perform a simple RPC where the server cancels the request with
  65 // grpc_call_cancel_with_status
  66 grpc_status_code PerformCall(grpc_channel* channel, grpc_server* server,
  67                              grpc_completion_queue* cq) {
  68   grpc_call* c;
  69   grpc_call* s;
  70   cq_verifier* cqv = cq_verifier_create(cq);
  71   grpc_op ops[6];
  72   grpc_op* op;
  73   grpc_metadata_array trailing_metadata_recv;
  74   grpc_metadata_array request_metadata_recv;
  75   grpc_call_details call_details;
  76   grpc_status_code status;
  77   grpc_call_error error;
  78   grpc_slice details;
  79   gpr_timespec deadline = grpc_timeout_seconds_to_deadline(5);
  80   // Start a call
  81   c = grpc_channel_create_call(channel, nullptr, GRPC_PROPAGATE_DEFAULTS, cq,
  82                                grpc_slice_from_static_string("/foo"), nullptr,
  83                                deadline, nullptr);
  84   GPR_ASSERT(c);
  85   grpc_metadata_array_init(&trailing_metadata_recv);
  86   grpc_metadata_array_init(&request_metadata_recv);
  87   grpc_call_details_init(&call_details);
  88   memset(ops, 0, sizeof(ops));
  89   op = ops;
  90   op->op = GRPC_OP_SEND_INITIAL_METADATA;
  91   op->data.send_initial_metadata.count = 0;
  92   op->flags = 0;
  93   op->reserved = nullptr;
  94   op++;
  95   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
  96   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
  97   op->data.recv_status_on_client.status = &status;
  98   op->data.recv_status_on_client.status_details = &details;
  99   op->flags = 0;
 100   op->reserved = nullptr;
 101   op++;
 102   error = grpc_call_start_batch(c, ops, static_cast<size_t>(op - ops), tag(1),
 103                                 nullptr);
 104   GPR_ASSERT(GRPC_CALL_OK == error);
 105   // Request a call on the server
 106   error = grpc_server_request_call(server, &s, &call_details,
 107                                    &request_metadata_recv, cq, cq, tag(101));
 108   GPR_ASSERT(GRPC_CALL_OK == error);
 109   CQ_EXPECT_COMPLETION(cqv, tag(101), 1);
 110   cq_verify(cqv);
 111   grpc_call_cancel_with_status(s, GRPC_STATUS_PERMISSION_DENIED, "test status",
 112                                nullptr);
 113   CQ_EXPECT_COMPLETION(cqv, tag(1), 1);
 114   cq_verify(cqv);
 115   // cleanup
 116   grpc_slice_unref(details);
 117   grpc_metadata_array_destroy(&trailing_metadata_recv);
 118   grpc_metadata_array_destroy(&request_metadata_recv);
 119   grpc_call_details_destroy(&call_details);
 120   grpc_call_unref(c);
 121   grpc_call_unref(s);
 122   cq_verifier_destroy(cqv);
 123   return status;
 124 }
 125
 126 // Test that sending a lot of RPCs that are cancelled by the server doesn't
 127 // result in too many pings due to the pings sent by BDP.
 128 TEST(TooManyPings, TestLotsOfServerCancelledRpcsDoesntGiveTooManyPings) {
 129   grpc_completion_queue* cq = grpc_completion_queue_create_for_next(nullptr);
 130   // create the server
 131   grpc_server* server = grpc_server_create(nullptr, nullptr);
 132   std::string server_address =
 133       grpc_core::JoinHostPort("localhost", grpc_pick_unused_port_or_die());
 134   grpc_server_register_completion_queue(server, cq, nullptr);
 135   GPR_ASSERT(
 136       grpc_server_add_insecure_http2_port(server, server_address.c_str()));
 137   grpc_server_start(server);
 138   // create the channel (bdp pings are enabled by default)
 139   grpc_channel* channel = grpc_insecure_channel_create(
 140       server_address.c_str(), nullptr /* channel args */, nullptr);
 141   std::map<grpc_status_code, int> statuses_and_counts;
 142   const int kNumTotalRpcs = 1e5;
 143   // perform an RPC
 144   gpr_log(GPR_INFO,
 145           "Performing %d total RPCs and expecting them all to receive status "
 146           "PERMISSION_DENIED (%d)",
 147           kNumTotalRpcs, GRPC_STATUS_PERMISSION_DENIED);
 148   for (int i = 0; i < kNumTotalRpcs; i++) {
 149     grpc_status_code status = PerformCall(channel, server, cq);
 150     statuses_and_counts[status] += 1;
 151   }
 152   int num_not_cancelled = 0;
 153   for (auto itr = statuses_and_counts.begin(); itr != statuses_and_counts.end();
 154        itr++) {
 155     if (itr->first != GRPC_STATUS_PERMISSION_DENIED) {
 156       num_not_cancelled += itr->second;
 157     }
 158     gpr_log(GPR_INFO, "%d / %d RPCs received status code: %d", itr->second,
 159             kNumTotalRpcs, itr->first);
 160   }
 161   if (num_not_cancelled > 0) {
 162     gpr_log(GPR_ERROR,
 163             "Expected all RPCs to receive status PERMISSION_DENIED (%d) but %d "
 164             "received other status codes",
 165             GRPC_STATUS_PERMISSION_DENIED, num_not_cancelled);
 166     FAIL();
 167   }
 168   // shutdown and destroy the client and server
 169   grpc_channel_destroy(channel);
 170   grpc_server_shutdown_and_notify(server, cq, nullptr);
 171   grpc_completion_queue_shutdown(cq);
 172   while (grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME),
 173                                     nullptr)
 174              .type != GRPC_QUEUE_SHUTDOWN) {
 175   }
 176   grpc_server_destroy(server);
 177   grpc_completion_queue_destroy(cq);
 178 }
 179
 180 // Perform a simple RPC where the client makes a request, and both the client
 181 // and server continue reading so that gRPC can send and receive keepalive
 182 // pings.
 183 grpc_status_code PerformWaitingCall(grpc_channel* channel, grpc_server* server,
 184                                     grpc_completion_queue* cq) {
 185   grpc_call* c;
 186   grpc_call* s;
 187   cq_verifier* cqv = cq_verifier_create(cq);
 188   grpc_op ops[6];
 189   grpc_op* op;
 190   grpc_metadata_array trailing_metadata_recv;
 191   grpc_metadata_array request_metadata_recv;
 192   grpc_call_details call_details;
 193   grpc_status_code status;
 194   grpc_call_error error;
 195   grpc_slice details;
 196   gpr_timespec deadline = grpc_timeout_seconds_to_deadline(15);
 197   // Start a call
 198   c = grpc_channel_create_call(channel, nullptr, GRPC_PROPAGATE_DEFAULTS, cq,
 199                                grpc_slice_from_static_string("/foo"), nullptr,
 200                                deadline, nullptr);
 201   GPR_ASSERT(c);
 202   grpc_metadata_array_init(&trailing_metadata_recv);
 203   grpc_metadata_array_init(&request_metadata_recv);
 204   grpc_call_details_init(&call_details);
 205   memset(ops, 0, sizeof(ops));
 206   op = ops;
 207   op->op = GRPC_OP_SEND_INITIAL_METADATA;
 208   op->data.send_initial_metadata.count = 0;
 209   op->flags = 0;
 210   op->reserved = nullptr;
 211   op++;
 212   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
 213   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
 214   op->data.recv_status_on_client.status = &status;
 215   op->data.recv_status_on_client.status_details = &details;
 216   op->flags = 0;
 217   op->reserved = nullptr;
 218   op++;
 219   error = grpc_call_start_batch(c, ops, static_cast<size_t>(op - ops), tag(1),
 220                                 nullptr);
 221   GPR_ASSERT(GRPC_CALL_OK == error);
 222   // Request a call on the server
 223   error = grpc_server_request_call(server, &s, &call_details,
 224                                    &request_metadata_recv, cq, cq, tag(101));
 225   GPR_ASSERT(GRPC_CALL_OK == error);
 226   CQ_EXPECT_COMPLETION(cqv, tag(101), 1);
 227   cq_verify(cqv);
 228   // Since the server is configured to allow only a single ping strike, it would
 229   // take 3 pings to trigger the GOAWAY frame with "too_many_pings" from the
 230   // server. (The second ping from the client would be the first bad ping sent
 231   // too quickly leading to a ping strike and the third ping would lead to the
 232   // GOAWAY.) If the client settings match with the server's settings, there
 233   // won't be a bad ping, and the call will end due to the deadline expiring
 234   // instead.
 235   CQ_EXPECT_COMPLETION(cqv, tag(1), 1);
 236   // The call will end after this
 237   cq_verify(cqv, 60);
 238   // cleanup
 239   grpc_slice_unref(details);
 240   grpc_metadata_array_destroy(&trailing_metadata_recv);
 241   grpc_metadata_array_destroy(&request_metadata_recv);
 242   grpc_call_details_destroy(&call_details);
 243   grpc_call_unref(c);
 244   grpc_call_unref(s);
 245   cq_verifier_destroy(cqv);
 246   return status;
 247 }
 248
 249 // Shuts down and destroys the server.
 250 void ServerShutdownAndDestroy(grpc_server* server, grpc_completion_queue* cq) {
 251   // Shutdown and destroy server
 252   grpc_server_shutdown_and_notify(server, cq, (void*)(1000));
 253   while (grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME),
 254                                     nullptr)
 255              .tag != (void*)(1000)) {
 256   }
 257   grpc_server_destroy(server);
 258 }
 259
 260 void VerifyChannelReady(grpc_channel* channel, grpc_completion_queue* cq) {
 261   grpc_connectivity_state state =
 262       grpc_channel_check_connectivity_state(channel, 1 /* try_to_connect */);
 263   while (state != GRPC_CHANNEL_READY) {
 264     grpc_channel_watch_connectivity_state(
 265         channel, state, grpc_timeout_seconds_to_deadline(5), cq, nullptr);
 266     grpc_completion_queue_next(cq, grpc_timeout_seconds_to_deadline(5),
 267                                nullptr);
 268     state = grpc_channel_check_connectivity_state(channel, 0);
 269   }
 270 }
 271
 272 void VerifyChannelDisconnected(grpc_channel* channel,
 273                                grpc_completion_queue* cq) {
 274   // Verify channel gets disconnected. Use a ping to make sure that clients
 275   // tries sending/receiving bytes if the channel is connected.
 276   grpc_channel_ping(channel, cq, (void*)(2000), nullptr);
 277   grpc_event ev = grpc_completion_queue_next(
 278       cq, grpc_timeout_seconds_to_deadline(5), nullptr);
 279   GPR_ASSERT(ev.type == GRPC_OP_COMPLETE);
 280   GPR_ASSERT(ev.tag == (void*)(2000));
 281   GPR_ASSERT(ev.success == 0);
 282   GPR_ASSERT(grpc_channel_check_connectivity_state(channel, 0) !=
 283              GRPC_CHANNEL_READY);
 284 }
 285
 286 class KeepaliveThrottlingTest : public ::testing::Test {
 287  protected:
 288   // Starts the server and makes sure that the channel is able to get connected.
 289   grpc_server* ServerStart(const char* addr, grpc_completion_queue* cq) {
 290     // Set up server channel args to expect pings at an interval of 5 seconds
 291     // and use a single ping strike
 292     grpc_arg server_args[] = {
 293         grpc_channel_arg_integer_create(
 294             const_cast<char*>(
 295                 GRPC_ARG_HTTP2_MIN_RECV_PING_INTERVAL_WITHOUT_DATA_MS),
 296             5 * 1000),
 297         grpc_channel_arg_integer_create(
 298             const_cast<char*>(GRPC_ARG_HTTP2_MAX_PING_STRIKES), 1)};
 299     grpc_channel_args server_channel_args = {GPR_ARRAY_SIZE(server_args),
 300                                              server_args};
 301     // Create server
 302     grpc_server* server = grpc_server_create(&server_channel_args, nullptr);
 303     grpc_server_register_completion_queue(server, cq, nullptr);
 304     GPR_ASSERT(grpc_server_add_insecure_http2_port(server, addr));
 305     grpc_server_start(server);
 306     return server;
 307   }
 308 };
 309
 310 TEST_F(KeepaliveThrottlingTest, KeepaliveThrottlingMultipleChannels) {
 311   grpc_completion_queue* cq = grpc_completion_queue_create_for_next(nullptr);
 312   std::string server_address =
 313       grpc_core::JoinHostPort("127.0.0.1", grpc_pick_unused_port_or_die());
 314   grpc_server* server = ServerStart(server_address.c_str(), cq);
 315   // create two channel with a keepalive ping interval of 1 second.
 316   grpc_arg client_args[] = {
 317       grpc_channel_arg_integer_create(
 318           const_cast<char*>(GRPC_ARG_HTTP2_MAX_PINGS_WITHOUT_DATA), 0),
 319       grpc_channel_arg_integer_create(
 320           const_cast<char*>(GRPC_ARG_KEEPALIVE_TIME_MS), 1 * 1000),
 321       grpc_channel_arg_integer_create(
 322           const_cast<char*>(GRPC_ARG_HTTP2_BDP_PROBE), 0)};
 323   grpc_channel_args client_channel_args = {GPR_ARRAY_SIZE(client_args),
 324                                            client_args};
 325   grpc_channel* channel = grpc_insecure_channel_create(
 326       server_address.c_str(), &client_channel_args, nullptr);
 327   grpc_channel* channel_dup = grpc_insecure_channel_create(
 328       server_address.c_str(), &client_channel_args, nullptr);
 329   int expected_keepalive_time_sec = 1;
 330   // We need 3 GOAWAY frames to throttle the keepalive time from 1 second to 8
 331   // seconds (> 5sec).
 332   for (int i = 0; i < 3; i++) {
 333     gpr_log(GPR_INFO, "Expected keepalive time : %d",
 334             expected_keepalive_time_sec);
 335     EXPECT_EQ(PerformWaitingCall(channel, server, cq), GRPC_STATUS_UNAVAILABLE);
 336     expected_keepalive_time_sec *= 2;
 337   }
 338   gpr_log(
 339       GPR_INFO,
 340       "Client keepalive time %d should now be in sync with the server settings",
 341       expected_keepalive_time_sec);
 342   EXPECT_EQ(PerformWaitingCall(channel, server, cq),
 343             GRPC_STATUS_DEADLINE_EXCEEDED);
 344   // Since the subchannel is shared, the second channel should also have
 345   // keepalive settings in sync with the server.
 346   gpr_log(GPR_INFO, "Now testing second channel sharing the same subchannel");
 347   EXPECT_EQ(PerformWaitingCall(channel_dup, server, cq),
 348             GRPC_STATUS_DEADLINE_EXCEEDED);
 349   // shutdown and destroy the client and server
 350   grpc_channel_destroy(channel);
 351   grpc_channel_destroy(channel_dup);
 352   ServerShutdownAndDestroy(server, cq);
 353   grpc_completion_queue_shutdown(cq);
 354   while (grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME),
 355                                     nullptr)
 356              .type != GRPC_QUEUE_SHUTDOWN) {
 357   }
 358   grpc_completion_queue_destroy(cq);
 359 }
 360
 361 grpc_core::Resolver::Result BuildResolverResult(
 362     const std::vector<std::string>& addresses) {
 363   grpc_core::Resolver::Result result;
 364   for (const auto& address_str : addresses) {
 365     grpc_uri* uri = grpc_uri_parse(address_str.c_str(), true);
 366     if (uri == nullptr) {
 367       gpr_log(GPR_ERROR, "Failed to parse uri:%s", address_str.c_str());
 368       GPR_ASSERT(0);
 369     }
 370     grpc_resolved_address address;
 371     GPR_ASSERT(grpc_parse_uri(uri, &address));
 372     result.addresses.emplace_back(address.addr, address.len, nullptr);
 373     grpc_uri_destroy(uri);
 374   }
 375   return result;
 376 }
 377
 378 // Tests that when new subchannels are created due to a change in resolved
 379 // addresses, the new subchannels use the updated keepalive time.
 380 TEST_F(KeepaliveThrottlingTest, NewSubchannelsUseUpdatedKeepaliveTime) {
 381   grpc_core::ExecCtx exec_ctx;
 382   grpc_completion_queue* cq = grpc_completion_queue_create_for_next(nullptr);
 383   std::string server_address1 =
 384       grpc_core::JoinHostPort("127.0.0.1", grpc_pick_unused_port_or_die());
 385   std::string server_address2 =
 386       grpc_core::JoinHostPort("127.0.0.1", grpc_pick_unused_port_or_die());
 387   grpc_server* server1 = ServerStart(server_address1.c_str(), cq);
 388   grpc_server* server2 = ServerStart(server_address2.c_str(), cq);
 389   // create a single channel with multiple subchannels with a keepalive ping
 390   // interval of 1 second. To get finer control on subchannel connection times,
 391   // we are using pick_first instead of round_robin and using the fake resolver
 392   // response generator to switch between the two.
 393   auto response_generator =
 394       grpc_core::MakeRefCounted<grpc_core::FakeResolverResponseGenerator>();
 395   grpc_arg client_args[] = {
 396       grpc_channel_arg_integer_create(
 397           const_cast<char*>(GRPC_ARG_HTTP2_MAX_PINGS_WITHOUT_DATA), 0),
 398       grpc_channel_arg_integer_create(
 399           const_cast<char*>(GRPC_ARG_KEEPALIVE_PERMIT_WITHOUT_CALLS), 0),
 400       grpc_channel_arg_integer_create(
 401           const_cast<char*>(GRPC_ARG_KEEPALIVE_TIME_MS), 1 * 1000),
 402       grpc_channel_arg_integer_create(
 403           const_cast<char*>(GRPC_ARG_HTTP2_BDP_PROBE), 0),
 404       grpc_core::FakeResolverResponseGenerator::MakeChannelArg(
 405           response_generator.get())};
 406   grpc_channel_args client_channel_args = {GPR_ARRAY_SIZE(client_args),
 407                                            client_args};
 408   grpc_channel* channel =
 409       grpc_insecure_channel_create("fake:///", &client_channel_args, nullptr);
 410   // For a single subchannel 3 GOAWAYs would be sufficient to increase the
 411   // keepalive time from 1 second to beyond 5 seconds. Even though we are
 412   // alternating between two subchannels, 3 GOAWAYs should still be enough since
 413   // the channel should start all new transports with the new keepalive value
 414   // (even those from a different subchannel).
 415   int expected_keepalive_time_sec = 1;
 416   for (int i = 0; i < 3; i++) {
 417     gpr_log(GPR_INFO, "Expected keepalive time : %d",
 418             expected_keepalive_time_sec);
 419     response_generator->SetResponse(BuildResolverResult({absl::StrCat(
 420         "ipv4:", i % 2 == 0 ? server_address1 : server_address2)}));
 421     // ExecCtx::Flush() might not be enough to make sure that the resolver
 422     // result has been propagated, so sleep for a bit.
 423     grpc_core::ExecCtx::Get()->Flush();
 424     gpr_sleep_until(grpc_timeout_seconds_to_deadline(1));
 425     EXPECT_EQ(PerformWaitingCall(channel, i % 2 == 0 ? server1 : server2, cq),
 426               GRPC_STATUS_UNAVAILABLE);
 427     expected_keepalive_time_sec *= 2;
 428   }
 429   gpr_log(
 430       GPR_INFO,
 431       "Client keepalive time %d should now be in sync with the server settings",
 432       expected_keepalive_time_sec);
 433   response_generator->SetResponse(
 434       BuildResolverResult({absl::StrCat("ipv4:", server_address2)}));
 435   grpc_core::ExecCtx::Get()->Flush();
 436   gpr_sleep_until(grpc_timeout_seconds_to_deadline(1));
 437   EXPECT_EQ(PerformWaitingCall(channel, server2, cq),
 438             GRPC_STATUS_DEADLINE_EXCEEDED);
 439   // shutdown and destroy the client and server
 440   grpc_channel_destroy(channel);
 441   ServerShutdownAndDestroy(server1, cq);
 442   ServerShutdownAndDestroy(server2, cq);
 443   grpc_completion_queue_shutdown(cq);
 444   while (grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME),
 445                                     nullptr)
 446              .type != GRPC_QUEUE_SHUTDOWN) {
 447   }
 448   grpc_completion_queue_destroy(cq);
 449 }
 450
 451 // Tests that when a channel has multiple subchannels and receives a GOAWAY with
 452 // "too_many_pings" on one of them, all subchannels start any new transports
 453 // with an updated keepalive time.
 454 TEST_F(KeepaliveThrottlingTest,
 455        ExistingSubchannelsUseNewKeepaliveTimeWhenReconnecting) {
 456   grpc_completion_queue* cq = grpc_completion_queue_create_for_next(nullptr);
 457   std::string server_address1 =
 458       grpc_core::JoinHostPort("127.0.0.1", grpc_pick_unused_port_or_die());
 459   std::string server_address2 =
 460       grpc_core::JoinHostPort("127.0.0.1", grpc_pick_unused_port_or_die());
 461   // create a single channel with round robin load balancing policy.
 462   auto response_generator =
 463       grpc_core::MakeRefCounted<grpc_core::FakeResolverResponseGenerator>();
 464   grpc_arg client_args[] = {
 465       grpc_channel_arg_integer_create(
 466           const_cast<char*>(GRPC_ARG_HTTP2_MAX_PINGS_WITHOUT_DATA), 0),
 467       grpc_channel_arg_integer_create(
 468           const_cast<char*>(GRPC_ARG_KEEPALIVE_PERMIT_WITHOUT_CALLS), 0),
 469       grpc_channel_arg_integer_create(
 470           const_cast<char*>(GRPC_ARG_KEEPALIVE_TIME_MS), 1 * 1000),
 471       grpc_channel_arg_integer_create(
 472           const_cast<char*>(GRPC_ARG_HTTP2_BDP_PROBE), 0),
 473       grpc_core::FakeResolverResponseGenerator::MakeChannelArg(
 474           response_generator.get())};
 475   grpc_channel_args client_channel_args = {GPR_ARRAY_SIZE(client_args),
 476                                            client_args};
 477   grpc_channel* channel =
 478       grpc_insecure_channel_create("fake:///", &client_channel_args, nullptr);
 479   response_generator->SetResponse(
 480       BuildResolverResult({absl::StrCat("ipv4:", server_address1),
 481                            absl::StrCat("ipv4:", server_address2)}));
 482   // For a single subchannel 3 GOAWAYs would be sufficient to increase the
 483   // keepalive time from 1 second to beyond 5 seconds. Even though we are
 484   // alternating between two subchannels, 3 GOAWAYs should still be enough since
 485   // the channel should start all new transports with the new keepalive value
 486   // (even those from a different subchannel).
 487   int expected_keepalive_time_sec = 1;
 488   for (int i = 0; i < 3; i++) {
 489     gpr_log(GPR_ERROR, "Expected keepalive time : %d",
 490             expected_keepalive_time_sec);
 491     grpc_server* server = ServerStart(
 492         i % 2 == 0 ? server_address1.c_str() : server_address2.c_str(), cq);
 493     VerifyChannelReady(channel, cq);
 494     EXPECT_EQ(PerformWaitingCall(channel, server, cq), GRPC_STATUS_UNAVAILABLE);
 495     ServerShutdownAndDestroy(server, cq);
 496     VerifyChannelDisconnected(channel, cq);
 497     expected_keepalive_time_sec *= 2;
 498   }
 499   gpr_log(
 500       GPR_INFO,
 501       "Client keepalive time %d should now be in sync with the server settings",
 502       expected_keepalive_time_sec);
 503   grpc_server* server = ServerStart(server_address1.c_str(), cq);
 504   VerifyChannelReady(channel, cq);
 505   EXPECT_EQ(PerformWaitingCall(channel, server, cq),
 506             GRPC_STATUS_DEADLINE_EXCEEDED);
 507   ServerShutdownAndDestroy(server, cq);
 508   // shutdown and destroy the client
 509   grpc_channel_destroy(channel);
 510   grpc_completion_queue_shutdown(cq);
 511   while (grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME),
 512                                     nullptr)
 513              .type != GRPC_QUEUE_SHUTDOWN) {
 514   }
 515   grpc_completion_queue_destroy(cq);
 516 }
 517
 518 // Perform a simple RPC where the client makes a request expecting a response
 519 // with payload.
 520 void PerformCallWithResponsePayload(grpc_channel* channel, grpc_server* server,
 521                                     grpc_completion_queue* cq) {
 522   grpc_slice response_payload_slice = grpc_slice_from_static_string("hello");
 523
 524   grpc_call* c;
 525   grpc_call* s;
 526   grpc_byte_buffer* response_payload =
 527       grpc_raw_byte_buffer_create(&response_payload_slice, 1);
 528   cq_verifier* cqv = cq_verifier_create(cq);
 529   grpc_op ops[6];
 530   grpc_op* op;
 531   grpc_metadata_array initial_metadata_recv;
 532   grpc_metadata_array trailing_metadata_recv;
 533   grpc_metadata_array request_metadata_recv;
 534   grpc_byte_buffer* response_payload_recv = nullptr;
 535   grpc_call_details call_details;
 536   grpc_status_code status;
 537   grpc_call_error error;
 538   grpc_slice details;
 539   int was_cancelled = 2;
 540
 541   gpr_timespec deadline = grpc_timeout_seconds_to_deadline(60);
 542   c = grpc_channel_create_call(channel, nullptr, GRPC_PROPAGATE_DEFAULTS, cq,
 543                                grpc_slice_from_static_string("/foo"), nullptr,
 544                                deadline, nullptr);
 545   GPR_ASSERT(c);
 546
 547   grpc_metadata_array_init(&initial_metadata_recv);
 548   grpc_metadata_array_init(&trailing_metadata_recv);
 549   grpc_metadata_array_init(&request_metadata_recv);
 550   grpc_call_details_init(&call_details);
 551
 552   memset(ops, 0, sizeof(ops));
 553   op = ops;
 554   op->op = GRPC_OP_SEND_INITIAL_METADATA;
 555   op->data.send_initial_metadata.count = 0;
 556   op->flags = 0;
 557   op->reserved = nullptr;
 558   op++;
 559   op->op = GRPC_OP_SEND_CLOSE_FROM_CLIENT;
 560   op->flags = 0;
 561   op->reserved = nullptr;
 562   op++;
 563   op->op = GRPC_OP_RECV_INITIAL_METADATA;
 564   op->data.recv_initial_metadata.recv_initial_metadata = &initial_metadata_recv;
 565   op->flags = 0;
 566   op->reserved = nullptr;
 567   op++;
 568   op->op = GRPC_OP_RECV_MESSAGE;
 569   op->data.recv_message.recv_message = &response_payload_recv;
 570   op->flags = 0;
 571   op->reserved = nullptr;
 572   op++;
 573   op->op = GRPC_OP_RECV_STATUS_ON_CLIENT;
 574   op->data.recv_status_on_client.trailing_metadata = &trailing_metadata_recv;
 575   op->data.recv_status_on_client.status = &status;
 576   op->data.recv_status_on_client.status_details = &details;
 577   op->flags = 0;
 578   op->reserved = nullptr;
 579   op++;
 580   error = grpc_call_start_batch(c, ops, static_cast<size_t>(op - ops), tag(1),
 581                                 nullptr);
 582   GPR_ASSERT(GRPC_CALL_OK == error);
 583
 584   error = grpc_server_request_call(server, &s, &call_details,
 585                                    &request_metadata_recv, cq, cq, tag(101));
 586   GPR_ASSERT(GRPC_CALL_OK == error);
 587   CQ_EXPECT_COMPLETION(cqv, tag(101), 1);
 588   cq_verify(cqv);
 589
 590   memset(ops, 0, sizeof(ops));
 591   op = ops;
 592   op->op = GRPC_OP_SEND_INITIAL_METADATA;
 593   op->data.send_initial_metadata.count = 0;
 594   op->flags = 0;
 595   op->reserved = nullptr;
 596   op++;
 597   error = grpc_call_start_batch(s, ops, static_cast<size_t>(op - ops), tag(102),
 598                                 nullptr);
 599   GPR_ASSERT(GRPC_CALL_OK == error);
 600
 601   CQ_EXPECT_COMPLETION(cqv, tag(102), 1);
 602   cq_verify(cqv);
 603
 604   memset(ops, 0, sizeof(ops));
 605   op = ops;
 606   op->op = GRPC_OP_RECV_CLOSE_ON_SERVER;
 607   op->data.recv_close_on_server.cancelled = &was_cancelled;
 608   op->flags = 0;
 609   op->reserved = nullptr;
 610   op++;
 611   op->op = GRPC_OP_SEND_MESSAGE;
 612   op->data.send_message.send_message = response_payload;
 613   op->flags = 0;
 614   op->reserved = nullptr;
 615   op++;
 616   op->op = GRPC_OP_SEND_STATUS_FROM_SERVER;
 617   op->data.send_status_from_server.trailing_metadata_count = 0;
 618   op->data.send_status_from_server.status = GRPC_STATUS_OK;
 619   grpc_slice status_details = grpc_slice_from_static_string("xyz");
 620   op->data.send_status_from_server.status_details = &status_details;
 621   op->flags = 0;
 622   op->reserved = nullptr;
 623   op++;
 624   error = grpc_call_start_batch(s, ops, static_cast<size_t>(op - ops), tag(103),
 625                                 nullptr);
 626   GPR_ASSERT(GRPC_CALL_OK == error);
 627
 628   CQ_EXPECT_COMPLETION(cqv, tag(103), 1);
 629   CQ_EXPECT_COMPLETION(cqv, tag(1), 1);
 630   cq_verify(cqv);
 631
 632   GPR_ASSERT(status == GRPC_STATUS_OK);
 633   GPR_ASSERT(0 == grpc_slice_str_cmp(details, "xyz"));
 634   GPR_ASSERT(0 == grpc_slice_str_cmp(call_details.method, "/foo"));
 635   GPR_ASSERT(was_cancelled == 0);
 636   GPR_ASSERT(
 637       byte_buffer_eq_slice(response_payload_recv, response_payload_slice));
 638
 639   grpc_slice_unref(details);
 640   grpc_metadata_array_destroy(&initial_metadata_recv);
 641   grpc_metadata_array_destroy(&trailing_metadata_recv);
 642   grpc_metadata_array_destroy(&request_metadata_recv);
 643   grpc_call_details_destroy(&call_details);
 644
 645   grpc_call_unref(c);
 646   grpc_call_unref(s);
 647
 648   cq_verifier_destroy(cqv);
 649
 650   grpc_byte_buffer_destroy(response_payload);
 651   grpc_byte_buffer_destroy(response_payload_recv);
 652 }
 653
 654 TEST(TooManyPings, BdpPingNotSentWithoutReceiveSideActivity) {
 655   grpc_completion_queue* cq = grpc_completion_queue_create_for_next(nullptr);
 656   // create the server
 657   std::string server_address =
 658       grpc_core::JoinHostPort("localhost", grpc_pick_unused_port_or_die());
 659   grpc_arg server_args[] = {
 660       grpc_channel_arg_integer_create(
 661           const_cast<char*>(
 662               GRPC_ARG_HTTP2_MIN_RECV_PING_INTERVAL_WITHOUT_DATA_MS),
 663           60 * 1000),
 664       grpc_channel_arg_integer_create(
 665           const_cast<char*>(GRPC_ARG_HTTP2_MAX_PING_STRIKES), 1)};
 666   grpc_channel_args server_channel_args = {GPR_ARRAY_SIZE(server_args),
 667                                            server_args};
 668   grpc_server* server = grpc_server_create(&server_channel_args, nullptr);
 669   grpc_server_register_completion_queue(server, cq, nullptr);
 670   GPR_ASSERT(
 671       grpc_server_add_insecure_http2_port(server, server_address.c_str()));
 672   grpc_server_start(server);
 673   // create the channel (bdp pings are enabled by default)
 674   grpc_arg client_args[] = {
 675       grpc_channel_arg_integer_create(
 676           const_cast<char*>(GRPC_ARG_HTTP2_MAX_PINGS_WITHOUT_DATA), 0),
 677       grpc_channel_arg_integer_create(
 678           const_cast<char*>(GRPC_ARG_KEEPALIVE_PERMIT_WITHOUT_CALLS), 1)};
 679   grpc_channel_args client_channel_args = {GPR_ARRAY_SIZE(client_args),
 680                                            client_args};
 681   grpc_channel* channel = grpc_insecure_channel_create(
 682       server_address.c_str(), &client_channel_args, nullptr);
 683   VerifyChannelReady(channel, cq);
 684   cq_verifier* cqv = cq_verifier_create(cq);
 685   cq_verify_empty_timeout(cqv, 1);
 686   // Channel should be able to send two pings without disconnect if there was no
 687   // BDP sent.
 688   grpc_channel_ping(channel, cq, tag(1), nullptr);
 689   CQ_EXPECT_COMPLETION(cqv, tag(1), 1);
 690   cq_verify(cqv, 5);
 691   // Second ping
 692   grpc_channel_ping(channel, cq, tag(2), nullptr);
 693   CQ_EXPECT_COMPLETION(cqv, tag(2), 1);
 694   cq_verify(cqv, 5);
 695   ASSERT_EQ(grpc_channel_check_connectivity_state(channel, 0),
 696             GRPC_CHANNEL_READY);
 697   PerformCallWithResponsePayload(channel, server, cq);
 698   // Wait a bit to make sure that the BDP ping goes out.
 699   cq_verify_empty_timeout(cqv, 1);
 700   // The call with a response payload should have triggered a BDP ping.
 701   // Send two more pings to verify. The second ping should cause a disconnect.
 702   // If BDP was not sent, the second ping would not cause a disconnect.
 703   grpc_channel_ping(channel, cq, tag(3), nullptr);
 704   CQ_EXPECT_COMPLETION(cqv, tag(3), 1);
 705   cq_verify(cqv, 5);
 706   // Second ping
 707   grpc_channel_ping(channel, cq, tag(4), nullptr);
 708   CQ_EXPECT_COMPLETION(cqv, tag(4), 1);
 709   cq_verify(cqv, 5);
 710   cq_verify_empty_timeout(cqv, 1);
 711   ASSERT_NE(grpc_channel_check_connectivity_state(channel, 0),
 712             GRPC_CHANNEL_READY);
 713   cq_verifier_destroy(cqv);
 714   // shutdown and destroy the client and server
 715   ServerShutdownAndDestroy(server, cq);
 716   grpc_channel_destroy(channel);
 717   grpc_completion_queue_shutdown(cq);
 718   while (grpc_completion_queue_next(cq, gpr_inf_future(GPR_CLOCK_REALTIME),
 719                                     nullptr)
 720              .type != GRPC_QUEUE_SHUTDOWN) {
 721   }
 722   grpc_completion_queue_destroy(cq);
 723 }
 724
 725 }  // namespace
 726
 727 int main(int argc, char** argv) {
 728   ::testing::InitGoogleTest(&argc, argv);
 729   grpc::testing::TestEnvironment env(argc, argv);
 730   grpc_init();
 731   auto result = RUN_ALL_TESTS();
 732   grpc_shutdown();
 733   return result;
 734 }