Added long_connection test.

doc/interop-test-descriptions.md

@@ -944,6 +944,11 @@ the experimental flag, `soak_iterations`.
 This tests puts stress on several gRPC components; the resolver, the load 
 balancer, and the RPC hotpath.
 
+#### long_connection
+
+The client performs a number of large_unary RPCs over a single connection
+with a fixed but configuration interval between the RPCs.
+
 ### TODO Tests
 
 #### High priority:

test/cpp/interop/client.cc

@@ -57,6 +57,7 @@ DEFINE_string(
     "half_duplex : half-duplex streaming;\n"
     "jwt_token_creds: large_unary with JWT token auth;\n"
     "large_unary : single request and (large) response;\n"
+    "long_connection: sends large_unary rpcs over a single long connection;\n"
     "oauth2_auth_token: raw oauth2 access token auth;\n"
     "per_rpc_creds: raw oauth2 access token on a single rpc;\n"
     "ping_pong : full-duplex streaming;\n"
@@ -84,10 +85,12 @@ DEFINE_bool(do_not_abort_on_transient_failures, false,
             "whether abort() is called or not. It does not control whether the "
             "test is retried in case of transient failures (and currently the "
             "interop tests are not retried even if this flag is set to true)");
-
 DEFINE_int32(soak_iterations, 1000,
              "number of iterations to use for the two soak tests; rpc_soak and "
              "channel_soak");
+DEFINE_int32(iteration_interval, 10,
+             "The interval in seconds between rpcs. This is used by "
+             "long_connection test");
 
 using grpc::testing::CreateChannelForTestCase;
 using grpc::testing::GetServiceAccountJsonKey;
@@ -163,6 +166,9 @@ int main(int argc, char** argv) {
                 FLAGS_soak_iterations);
   actions["rpc_soak"] = std::bind(&grpc::testing::InteropClient::DoRpcSoakTest,
                                   &client, FLAGS_soak_iterations);
+  actions["long_connection"] =
+      std::bind(&grpc::testing::InteropClient::DoLongConnectionTest, &client,
+                FLAGS_soak_iterations, FLAGS_iteration_interval);
 
   UpdateActions(&actions);
 

test/cpp/interop/interop_client.cc

@@ -1052,6 +1052,34 @@ bool InteropClient::DoChannelSoakTest(int32_t soak_iterations) {
   return true;
 }
 
+bool InteropClient::DoLongConnectionTest(int32_t soak_iterations,
+                                         int32_t iteration_interval) {
+  gpr_log(GPR_DEBUG, "Sending %d RPCs...", soak_iterations);
+  GPR_ASSERT(soak_iterations > 0);
+  GPR_ASSERT(iteration_interval > 0);
+  SimpleRequest request;
+  SimpleResponse response;
+  int num_failures = 0;
+  for (int i = 0; i < soak_iterations; ++i) {
+    gpr_log(GPR_DEBUG, "Sending RPC number %d...", i);
+    if (!PerformLargeUnary(&request, &response)) {
+      gpr_log(GPR_ERROR, "Iteration %d failed.", i);
+      num_failures++;
+    }
+    gpr_sleep_until(
+        gpr_time_add(gpr_now(GPR_CLOCK_REALTIME),
+                     gpr_time_from_seconds(iteration_interval, GPR_TIMESPAN)));
+  }
+  if (num_failures == 0) {
+    gpr_log(GPR_DEBUG, "long_connection test done.");
+    return true;
+  } else {
+    gpr_log(GPR_DEBUG, "long_connection test failed with %d rpc failures.",
+            num_failures);
+    return false;
+  }
+}
+
 bool InteropClient::DoUnimplementedService() {
   gpr_log(GPR_DEBUG, "Sending a request for an unimplemented service...");
 

test/cpp/interop/interop_client.h

@@ -76,6 +76,8 @@ class InteropClient {
   // languages
   bool DoChannelSoakTest(int32_t soak_iterations);
   bool DoRpcSoakTest(int32_t soak_iterations);
+  bool DoLongConnectionTest(int32_t soak_iterations,
+                            int32_t iteration_interval);
 
   // Auth tests.
   // username is a string containing the user email