Interop stress tests

5 files changed, 500 insertions, 31 deletions

diff --git a/test/cpp/interop/interop_client.cc b/test/cpp/interop/interop_client.cc
index 5169945762..fd01ad0666 100644
--- a/test/cpp/interop/interop_client.cc
+++ b/test/cpp/interop/interop_client.cc
@@ -83,7 +83,7 @@ CompressionType GetInteropCompressionTypeFromCompressionAlgorithm(
 }  // namespace
 
 InteropClient::InteropClient(std::shared_ptr<Channel> channel)
-    : channel_(channel) {}
+    : channel_(channel), stub_(TestService::NewStub(channel)) {}
 
 void InteropClient::AssertOkOrPrintErrorStatus(const Status& s) {
   if (s.ok()) {
@@ -96,13 +96,12 @@ void InteropClient::AssertOkOrPrintErrorStatus(const Status& s) {
 
 void InteropClient::DoEmpty() {
   gpr_log(GPR_INFO, "Sending an empty rpc...");
-  std::unique_ptr<TestService::Stub> stub(TestService::NewStub(channel_));
 
   Empty request = Empty::default_instance();
   Empty response = Empty::default_instance();
   ClientContext context;
 
-  Status s = stub->EmptyCall(&context, request, &response);
+  Status s = stub_->EmptyCall(&context, request, &response);
   AssertOkOrPrintErrorStatus(s);
 
   gpr_log(GPR_INFO, "Empty rpc done.");
@@ -111,7 +110,6 @@ void InteropClient::DoEmpty() {
 // Shared code to set large payload, make rpc and check response payload.
 void InteropClient::PerformLargeUnary(SimpleRequest* request,
                                       SimpleResponse* response) {
-  std::unique_ptr<TestService::Stub> stub(TestService::NewStub(channel_));
 
   ClientContext context;
   InteropClientContextInspector inspector(context);
@@ -121,7 +119,7 @@ void InteropClient::PerformLargeUnary(SimpleRequest* request,
   grpc::string payload(kLargeRequestSize, '\0');
   request->mutable_payload()->set_body(payload.c_str(), kLargeRequestSize);
 
-  Status s = stub->UnaryCall(&context, *request, response);
+  Status s = stub_->UnaryCall(&context, *request, response);
 
   // Compression related checks.
   GPR_ASSERT(request->response_compression() ==
@@ -187,11 +185,10 @@ void InteropClient::DoOauth2AuthToken(const grpc::string& username,
   SimpleResponse response;
   request.set_fill_username(true);
   request.set_fill_oauth_scope(true);
-  std::unique_ptr<TestService::Stub> stub(TestService::NewStub(channel_));
 
   ClientContext context;
 
-  Status s = stub->UnaryCall(&context, request, &response);
+  Status s = stub_->UnaryCall(&context, request, &response);
 
   AssertOkOrPrintErrorStatus(s);
   GPR_ASSERT(!response.username().empty());
@@ -207,7 +204,6 @@ void InteropClient::DoPerRpcCreds(const grpc::string& json_key) {
   SimpleRequest request;
   SimpleResponse response;
   request.set_fill_username(true);
-  std::unique_ptr<TestService::Stub> stub(TestService::NewStub(channel_));
 
   ClientContext context;
   std::chrono::seconds token_lifetime = std::chrono::hours(1);
@@ -216,7 +212,7 @@ void InteropClient::DoPerRpcCreds(const grpc::string& json_key) {
 
   context.set_credentials(creds);
 
-  Status s = stub->UnaryCall(&context, request, &response);
+  Status s = stub_->UnaryCall(&context, request, &response);
 
   AssertOkOrPrintErrorStatus(s);
   GPR_ASSERT(!response.username().empty());
@@ -269,14 +265,13 @@ void InteropClient::DoLargeCompressedUnary() {
 
 void InteropClient::DoRequestStreaming() {
   gpr_log(GPR_INFO, "Sending request steaming rpc ...");
-  std::unique_ptr<TestService::Stub> stub(TestService::NewStub(channel_));
 
   ClientContext context;
   StreamingInputCallRequest request;
   StreamingInputCallResponse response;
 
   std::unique_ptr<ClientWriter<StreamingInputCallRequest>> stream(
-      stub->StreamingInputCall(&context, &response));
+      stub_->StreamingInputCall(&context, &response));
 
   int aggregated_payload_size = 0;
   for (unsigned int i = 0; i < request_stream_sizes.size(); ++i) {
@@ -295,7 +290,6 @@ void InteropClient::DoRequestStreaming() {
 
 void InteropClient::DoResponseStreaming() {
   gpr_log(GPR_INFO, "Receiving response steaming rpc ...");
-  std::unique_ptr<TestService::Stub> stub(TestService::NewStub(channel_));
 
   ClientContext context;
   StreamingOutputCallRequest request;
@@ -305,7 +299,7 @@ void InteropClient::DoResponseStreaming() {
   }
   StreamingOutputCallResponse response;
   std::unique_ptr<ClientReader<StreamingOutputCallResponse>> stream(
-      stub->StreamingOutputCall(&context, request));
+      stub_->StreamingOutputCall(&context, request));
 
   unsigned int i = 0;
   while (stream->Read(&response)) {
@@ -320,7 +314,6 @@ void InteropClient::DoResponseStreaming() {
 }
 
 void InteropClient::DoResponseCompressedStreaming() {
-  std::unique_ptr<TestService::Stub> stub(TestService::NewStub(channel_));
 
   const CompressionType compression_types[] = {NONE, GZIP, DEFLATE};
   const PayloadType payload_types[] = {COMPRESSABLE, UNCOMPRESSABLE, RANDOM};
@@ -348,7 +341,7 @@ void InteropClient::DoResponseCompressedStreaming() {
       StreamingOutputCallResponse response;
 
       std::unique_ptr<ClientReader<StreamingOutputCallResponse>> stream(
-          stub->StreamingOutputCall(&context, request));
+          stub_->StreamingOutputCall(&context, request));
 
       size_t k = 0;
       while (stream->Read(&response)) {
@@ -401,7 +394,6 @@ void InteropClient::DoResponseCompressedStreaming() {
 
 void InteropClient::DoResponseStreamingWithSlowConsumer() {
   gpr_log(GPR_INFO, "Receiving response steaming rpc with slow consumer ...");
-  std::unique_ptr<TestService::Stub> stub(TestService::NewStub(channel_));
 
   ClientContext context;
   StreamingOutputCallRequest request;
@@ -412,7 +404,7 @@ void InteropClient::DoResponseStreamingWithSlowConsumer() {
   }
   StreamingOutputCallResponse response;
   std::unique_ptr<ClientReader<StreamingOutputCallResponse>> stream(
-      stub->StreamingOutputCall(&context, request));
+      stub_->StreamingOutputCall(&context, request));
 
   int i = 0;
   while (stream->Read(&response)) {
@@ -431,12 +423,11 @@ void InteropClient::DoResponseStreamingWithSlowConsumer() {
 
 void InteropClient::DoHalfDuplex() {
   gpr_log(GPR_INFO, "Sending half-duplex streaming rpc ...");
-  std::unique_ptr<TestService::Stub> stub(TestService::NewStub(channel_));
 
   ClientContext context;
   std::unique_ptr<ClientReaderWriter<StreamingOutputCallRequest,
                                      StreamingOutputCallResponse>>
-      stream(stub->HalfDuplexCall(&context));
+      stream(stub_->HalfDuplexCall(&context));
 
   StreamingOutputCallRequest request;
   ResponseParameters* response_parameter = request.add_response_parameters();
@@ -461,12 +452,11 @@ void InteropClient::DoHalfDuplex() {
 
 void InteropClient::DoPingPong() {
   gpr_log(GPR_INFO, "Sending Ping Pong streaming rpc ...");
-  std::unique_ptr<TestService::Stub> stub(TestService::NewStub(channel_));
 
   ClientContext context;
   std::unique_ptr<ClientReaderWriter<StreamingOutputCallRequest,
                                      StreamingOutputCallResponse>>
-      stream(stub->FullDuplexCall(&context));
+      stream(stub_->FullDuplexCall(&context));
 
   StreamingOutputCallRequest request;
   request.set_response_type(PayloadType::COMPRESSABLE);
@@ -491,14 +481,13 @@ void InteropClient::DoPingPong() {
 
 void InteropClient::DoCancelAfterBegin() {
   gpr_log(GPR_INFO, "Sending request steaming rpc ...");
-  std::unique_ptr<TestService::Stub> stub(TestService::NewStub(channel_));
 
   ClientContext context;
   StreamingInputCallRequest request;
   StreamingInputCallResponse response;
 
   std::unique_ptr<ClientWriter<StreamingInputCallRequest>> stream(
-      stub->StreamingInputCall(&context, &response));
+      stub_->StreamingInputCall(&context, &response));
 
   gpr_log(GPR_INFO, "Trying to cancel...");
   context.TryCancel();
@@ -509,12 +498,11 @@ void InteropClient::DoCancelAfterBegin() {
 
 void InteropClient::DoCancelAfterFirstResponse() {
   gpr_log(GPR_INFO, "Sending Ping Pong streaming rpc ...");
-  std::unique_ptr<TestService::Stub> stub(TestService::NewStub(channel_));
 
   ClientContext context;
   std::unique_ptr<ClientReaderWriter<StreamingOutputCallRequest,
                                      StreamingOutputCallResponse>>
-      stream(stub->FullDuplexCall(&context));
+      stream(stub_->FullDuplexCall(&context));
 
   StreamingOutputCallRequest request;
   request.set_response_type(PayloadType::COMPRESSABLE);
@@ -534,7 +522,6 @@ void InteropClient::DoCancelAfterFirstResponse() {
 
 void InteropClient::DoTimeoutOnSleepingServer() {
   gpr_log(GPR_INFO, "Sending Ping Pong streaming rpc with a short deadline...");
-  std::unique_ptr<TestService::Stub> stub(TestService::NewStub(channel_));
 
   ClientContext context;
   std::chrono::system_clock::time_point deadline =
@@ -542,7 +529,7 @@ void InteropClient::DoTimeoutOnSleepingServer() {
   context.set_deadline(deadline);
   std::unique_ptr<ClientReaderWriter<StreamingOutputCallRequest,
                                      StreamingOutputCallResponse>>
-      stream(stub->FullDuplexCall(&context));
+      stream(stub_->FullDuplexCall(&context));
 
   StreamingOutputCallRequest request;
   request.mutable_payload()->set_body(grpc::string(27182, '\0'));
@@ -555,12 +542,11 @@ void InteropClient::DoTimeoutOnSleepingServer() {
 
 void InteropClient::DoEmptyStream() {
   gpr_log(GPR_INFO, "Starting empty_stream.");
-  std::unique_ptr<TestService::Stub> stub(TestService::NewStub(channel_));
 
   ClientContext context;
   std::unique_ptr<ClientReaderWriter<StreamingOutputCallRequest,
                                      StreamingOutputCallResponse>>
-      stream(stub->FullDuplexCall(&context));
+      stream(stub_->FullDuplexCall(&context));
   stream->WritesDone();
   StreamingOutputCallResponse response;
   GPR_ASSERT(stream->Read(&response) == false);
@@ -571,7 +557,6 @@ void InteropClient::DoEmptyStream() {
 
 void InteropClient::DoStatusWithMessage() {
   gpr_log(GPR_INFO, "Sending RPC with a request for status code 2 and message");
-  std::unique_ptr<TestService::Stub> stub(TestService::NewStub(channel_));
 
   ClientContext context;
   SimpleRequest request;
@@ -581,7 +566,7 @@ void InteropClient::DoStatusWithMessage() {
   grpc::string test_msg = "This is a test message";
   requested_status->set_message(test_msg);
 
-  Status s = stub->UnaryCall(&context, request, &response);
+  Status s = stub_->UnaryCall(&context, request, &response);
 
   GPR_ASSERT(s.error_code() == grpc::StatusCode::UNKNOWN);
   GPR_ASSERT(s.error_message() == test_msg);
diff --git a/test/cpp/interop/interop_client.h b/test/cpp/interop/interop_client.h
index ebecd68c3f..1f13d5b971 100644
--- a/test/cpp/interop/interop_client.h
+++ b/test/cpp/interop/interop_client.h
@@ -39,6 +39,7 @@
 #include <grpc/grpc.h>
 #include <grpc++/channel.h>
 #include "test/proto/messages.grpc.pb.h"
+#include "test/proto/test.grpc.pb.h"
 
 namespace grpc {
 namespace testing {
@@ -80,6 +81,7 @@ class InteropClient {
   void AssertOkOrPrintErrorStatus(const Status& s);
 
   std::shared_ptr<Channel> channel_;
+  std::unique_ptr<TestService::Stub> stub_;
 };
 
 }  // namespace testing
diff --git a/test/cpp/interop/stress_interop_client.cc b/test/cpp/interop/stress_interop_client.cc
new file mode 100644
index 0000000000..7b499a8d78
--- /dev/null
+++ b/test/cpp/interop/stress_interop_client.cc
@@ -0,0 +1,158 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *is % allowed in string
+ */
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include <grpc++/create_channel.h>
+
+#include "test/cpp/interop/interop_client.h"
+#include "test/cpp/interop/stress_interop_client.h"
+
+namespace grpc {
+namespace testing {
+
+using std::pair;
+using std::string;
+using std::vector;
+
+TestSelector::TestSelector(const vector<pair<TestCaseType, int>>& tests)
+    : tests_(tests) {
+  total_weight_ = 0;
+  for (auto it = tests.begin(); it != tests.end(); it++) {
+    total_weight_ += it->second;
+  }
+}
+
+TestCaseType TestSelector::GetNextTest() const {
+  int random = 0;
+  TestCaseType selected_test = UNKNOWN_TEST;
+
+  // Get a random number from [0 to the total_weight - 1]
+  random = rand() % total_weight_;
+
+  int weight_sofar = 0;
+  for (auto it = tests_.begin(); it != tests_.end(); it++) {
+    weight_sofar += it->second;
+    if (random < weight_sofar) {
+      selected_test = it->first;
+      break;
+    }
+  }
+
+  // It is a bug in the logic if no test is selected at this point
+  GPR_ASSERT(selected_test != UNKNOWN_TEST);
+  return selected_test;
+}
+
+StressTestInteropClient::StressTestInteropClient(
+    int test_id, const string& server_address,
+    const TestSelector& test_selector, long test_duration_secs,
+    long sleep_duration_ms)
+    : test_id_(test_id),
+      server_address_(server_address),
+      test_selector_(test_selector),
+      test_duration_secs_(test_duration_secs),
+      sleep_duration_ms_(sleep_duration_ms) {
+  // TODO(sreek): This will change once we add support for other tests
+  // that won't work with InsecureCredentials()
+  std::shared_ptr<Channel> channel(
+      CreateChannel(server_address, InsecureCredentials()));
+  interop_client_.reset(new InteropClient(channel));
+}
+
+void StressTestInteropClient::MainLoop() {
+  gpr_log(GPR_INFO, "Running test %d. ServerAddr: %s", test_id_,
+          server_address_.c_str());
+
+  gpr_timespec test_end_time =
+      gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
+                   gpr_time_from_seconds(test_duration_secs_, GPR_TIMESPAN));
+
+  gpr_timespec current_time = gpr_now(GPR_CLOCK_REALTIME);
+  while (test_duration_secs_ < 0 ||
+         gpr_time_cmp(current_time, test_end_time) < 0) {
+    // Select the test case to execute based on the weights and execute it
+    TestCaseType test_case = test_selector_.GetNextTest();
+    gpr_log(GPR_INFO, "%d - Executing the test case %d", test_id_, test_case);
+    RunTest(test_case);
+
+    // Sleep between successive calls if needed
+    if (sleep_duration_ms_ > 0) {
+      gpr_timespec sleep_time = gpr_time_add(
+          current_time, gpr_time_from_millis(sleep_duration_ms_, GPR_TIMESPAN));
+      gpr_sleep_until(sleep_time);
+    }
+
+    current_time = gpr_now(GPR_CLOCK_REALTIME);
+  }
+}
+
+// TODO(sree): Add all interop tests
+void StressTestInteropClient::RunTest(TestCaseType test_case) {
+  switch (test_case) {
+    case EMPTY_UNARY: {
+      interop_client_->DoEmpty();
+      break;
+    }
+    case LARGE_UNARY: {
+      interop_client_->DoLargeUnary();
+      break;
+    }
+    case LARGE_COMPRESSED_UNARY: {
+      interop_client_->DoLargeCompressedUnary();
+      break;
+    }
+    case CLIENT_STREAMING: {
+      interop_client_->DoRequestStreaming();
+      break;
+    }
+    case SERVER_STREAMING: {
+      interop_client_->DoResponseStreaming();
+      break;
+    }
+    case EMPTY_STREAM: {
+      interop_client_->DoEmptyStream();
+      break;
+    }
+    default: {
+      gpr_log(GPR_ERROR, "Invalid test case (%d)", test_case);
+      GPR_ASSERT(false);
+      break;
+    }
+  }
+}
+
+}  // namespace testing
+}  // namespace grpc
diff --git a/test/cpp/interop/stress_interop_client.h b/test/cpp/interop/stress_interop_client.h
new file mode 100644
index 0000000000..7e7af00626
--- /dev/null
+++ b/test/cpp/interop/stress_interop_client.h
@@ -0,0 +1,103 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *is % allowed in string
+ */
+
+#ifndef GRPC_TEST_CPP_STRESS_INTEROP_CLIENT_H
+#define GRPC_TEST_CPP_STRESS_INTEROP_CLIENT_H
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include <grpc++/create_channel.h>
+
+#include "test/cpp/interop/interop_client.h"
+
+namespace grpc {
+namespace testing {
+
+using std::pair;
+using std::string;
+using std::vector;
+
+// TODO(sreek): Add more test cases here in future
+enum TestCaseType {
+  UNKNOWN_TEST = -1,
+  EMPTY_UNARY = 0,
+  LARGE_UNARY = 1,
+  LARGE_COMPRESSED_UNARY = 2,
+  CLIENT_STREAMING = 3,
+  SERVER_STREAMING = 4,
+  EMPTY_STREAM = 5
+};
+
+const vector<pair<TestCaseType, string>> kTestCaseList = {
+    {EMPTY_UNARY, "empty_unary"},
+    {LARGE_UNARY, "large_unary"},
+    {LARGE_COMPRESSED_UNARY, "large_compressed_unary"},
+    {CLIENT_STREAMING, "client_streaming"},
+    {SERVER_STREAMING, "server_streaming"},
+    {EMPTY_STREAM, "empty_stream"}};
+
+class TestSelector {
+ public:
+  TestSelector(const vector<pair<TestCaseType, int>>& tests);
+  TestCaseType GetNextTest() const;
+
+ private:
+  const vector<pair<TestCaseType, int>> tests_;
+  int total_weight_;
+};
+
+class StressTestInteropClient {
+ public:
+  StressTestInteropClient(int test_id, const string& server_address,
+                          const TestSelector& test_selector,
+                          long test_duration_secs, long sleep_duration_ms);
+
+  void MainLoop();  // The main test. Use this as the thread entry point.
+
+ private:
+  void RunTest(TestCaseType test_case);
+
+  int test_id_;
+  std::unique_ptr<InteropClient> interop_client_;
+  const string& server_address_;
+  const TestSelector& test_selector_;
+  long test_duration_secs_;
+  long sleep_duration_ms_;
+};
+
+} // namespace testing
+} // namespace grpc
+
+#endif // GRPC_TEST_CPP_STRESS_INTEROP_CLIENT_H
diff --git a/test/cpp/interop/stress_test.cc b/test/cpp/interop/stress_test.cc
new file mode 100644
index 0000000000..5cb1e1fc90
--- /dev/null
+++ b/test/cpp/interop/stress_test.cc
@@ -0,0 +1,221 @@
+/*
+ *
+ * Copyright 2015, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *is % allowed in string
+ */
+
+#include <memory>
+#include <string>
+#include <thread>
+#include <utility>
+#include <vector>
+
+#include <gflags/gflags.h>
+#include <grpc/support/time.h>
+#include <grpc++/create_channel.h>
+#include <grpc++/grpc++.h>
+
+#include "test/cpp/interop/interop_client.h"
+#include "test/cpp/interop/stress_interop_client.h"
+#include "test/cpp/util/test_config.h"
+
+DEFINE_int32(sleep_duration_ms, 0,
+             "The duration (in millisec) between two"
+             " consecutive test calls (per server) issued by the server.");
+
+DEFINE_int32(test_duration_secs, -1,
+             "The length of time (in seconds) to run"
+             " the test. Enter -1 if the test should run continuously until"
+             " forcefully terminated.");
+
+DEFINE_string(server_addresses, "localhost:8080",
+              "The list of server"
+              " addresses in the format:\n"
+              " \"<name_1>:<port_1>,<name_2>:<port_1>...<name_N>:<port_N>\"\n"
+              " Note: <name> can be servername or IP address.");
+
+// TODO(sreek): Add more test cases here in future
+DEFINE_string(test_cases, "",
+              "List of test cases to call along with the"
+              " relative weights in the following format:\n"
+              " \"<testcase_1:w_1>,<testcase_2:w_2>...<testcase_n:w_n>\"\n"
+              " The following testcases are currently supported:\n"
+              "   empty_unary\n"
+              "   large_unary\n"
+              "   large_compressed_unary\n"
+              "   client_streaming\n"
+              "   server_streaming\n"
+              "   empty_stream\n"
+              " Example: \"empty_unary:20,large_unary:10,empty_stream:70\"\n"
+              " The above will execute 'empty_unary', 20% of the time,"
+              " 'large_unary', 10% of the time and 'empty_stream' the remaining"
+              " 70% of the time");
+
+using std::make_pair;
+using std::pair;
+using std::string;
+using std::thread;
+using std::vector;
+
+using grpc::testing::kTestCaseList;
+using grpc::testing::StressTestInteropClient;
+using grpc::testing::TestCaseType;
+using grpc::testing::TestSelector;
+using grpc::testing::UNKNOWN_TEST;
+
+TestCaseType get_test_type_from_name(const string& test_name) {
+  TestCaseType test_case = UNKNOWN_TEST;
+
+  for (auto it = kTestCaseList.begin(); it != kTestCaseList.end(); it++) {
+    if (test_name == it->second) {
+      test_case = it->first;
+      break;
+    }
+  }
+
+  return test_case;
+}
+
+bool ParseCommaDelimitedString(const string& comma_delimited_str,
+                               vector<string>& tokens) {
+  size_t bpos = 0;
+  size_t epos = string::npos;
+
+  while ((epos = comma_delimited_str.find(',', bpos)) != string::npos) {
+    tokens.emplace_back(comma_delimited_str.substr(bpos, epos - bpos));
+    bpos = epos + 1;
+  }
+
+  tokens.emplace_back(comma_delimited_str.substr(bpos));  // Last token
+  return true;
+}
+
+// Input: Test case string "<testcase_name:weight>,<testcase_name:weight>...."
+// Output:
+//   - Whether parsing was successful (return value)
+//   - Vector of (test_type_enum, weight) pairs
+bool ParseTestCasesString(const string& test_cases,
+                          vector<pair<TestCaseType, int>>& tests) {
+  bool is_success = true;
+
+  vector<string> tokens;
+  ParseCommaDelimitedString(test_cases, tokens);
+
+  for (auto it = tokens.begin(); it != tokens.end(); it++) {
+    // Token is in the form <test_name>:<test_weight>
+    size_t colon_pos = it->find(':');
+    if (colon_pos == string::npos) {
+      gpr_log(GPR_ERROR, "Error in parsing test case string: %s", it->c_str());
+      is_success = false;
+      break;
+    }
+
+    string test_name = it->substr(0, colon_pos);
+    int weight = std::stoi(it->substr(colon_pos + 1));
+    TestCaseType test_case = get_test_type_from_name(test_name);
+
+    if (test_case == UNKNOWN_TEST) {
+      gpr_log(GPR_ERROR, "Unknown test case: %s", test_name.c_str());
+      is_success = false;
+      break;
+    }
+
+    tests.emplace_back(std::make_pair(test_case, weight));
+  }
+
+  return is_success;
+}
+
+// For debugging purposes
+void LogParameterInfo(const vector<string>& addresses,
+                      const vector<pair<TestCaseType, int>>& tests) {
+  gpr_log(GPR_INFO, "server_addresses: %s", FLAGS_server_addresses.c_str());
+  gpr_log(GPR_INFO, "test_cases : %s", FLAGS_test_cases.c_str());
+  gpr_log(GPR_INFO, "sleep_duration_ms: %d", FLAGS_sleep_duration_ms);
+  gpr_log(GPR_INFO, "test_duration_secs: %d", FLAGS_test_duration_secs);
+
+  int num = 0;
+  for (auto it = addresses.begin(); it != addresses.end(); it++) {
+    gpr_log(GPR_INFO, "%d:%s", ++num, it->c_str());
+  }
+
+  num = 0;
+  for (auto it = tests.begin(); it != tests.end(); it++) {
+    TestCaseType test_case = it->first;
+    int weight = it->second;
+    gpr_log(GPR_INFO, "%d. TestCaseType: %d, Weight: %d", ++num, test_case,
+            weight);
+  }
+}
+
+int main(int argc, char** argv) {
+  grpc::testing::InitTest(&argc, &argv, true);
+  gpr_log(GPR_INFO, "starting test..");
+
+  srand(time(NULL));
+
+  // Parse the server addresses
+  vector<string> server_addresses;
+  ParseCommaDelimitedString(FLAGS_server_addresses, server_addresses);
+
+  // Parse test cases and weights
+  if (FLAGS_test_cases.length() == 0) {
+    gpr_log(GPR_INFO, "Test cases string is empty");
+    return 1;
+  }
+
+  vector<pair<TestCaseType, int>> tests;
+  if (!ParseTestCasesString(FLAGS_test_cases, tests)) {
+    gpr_log(GPR_ERROR, "Error in parsing test cases string %s ",
+            FLAGS_test_cases.c_str());
+    return 1;
+  }
+
+  LogParameterInfo(server_addresses, tests);
+
+  TestSelector test_selector(tests);
+
+  vector<thread> test_threads;
+  int thread_idx = 0;
+  for (auto it = server_addresses.begin(); it != server_addresses.end(); it++) {
+    StressTestInteropClient* client = new StressTestInteropClient(
+        ++thread_idx, *it, test_selector, FLAGS_test_duration_secs,
+        FLAGS_sleep_duration_ms);
+
+    test_threads.emplace_back(
+        thread(&StressTestInteropClient::MainLoop, client));
+  }
+
+  for (auto it = test_threads.begin(); it != test_threads.end(); it++) {
+    it->join();
+  }
+
+  return 0;
+}