Merge pull request #2370 from ctiller/now-i-get-to-show-it-to-EVERYBODY

User agent string sending support

21 files changed, 200 insertions, 33 deletions

diff --git a/include/grpc++/channel_arguments.h b/include/grpc++/channel_arguments.h
index d726b9ffea..4d926377ec 100644
--- a/include/grpc++/channel_arguments.h
+++ b/include/grpc++/channel_arguments.h
@@ -54,6 +54,14 @@ class ChannelArguments {
   ChannelArguments() {}
   ~ChannelArguments() {}
 
+  ChannelArguments(const ChannelArguments& other);
+  ChannelArguments& operator=(ChannelArguments other) {
+    Swap(other);
+    return *this;
+  }
+
+  void Swap(ChannelArguments& other);
+
   // grpc specific channel argument setters
   // Set target name override for SSL host name checking.
   void SetSslTargetNameOverride(const grpc::string& name);
@@ -73,10 +81,6 @@ class ChannelArguments {
   friend class SecureCredentials;
   friend class testing::ChannelArgumentsTest;
 
-  // TODO(yangg) implement copy and assign
-  ChannelArguments(const ChannelArguments&);
-  ChannelArguments& operator=(const ChannelArguments&);
-
   // Returns empty string when it is not set.
   grpc::string GetSslTargetNameOverride() const;
 
diff --git a/include/grpc/grpc.h b/include/grpc/grpc.h
index 686984f775..504f0cce03 100644
--- a/include/grpc/grpc.h
+++ b/include/grpc/grpc.h
@@ -126,6 +126,12 @@ typedef struct {
 /** Initial sequence number for http2 transports */
 #define GRPC_ARG_HTTP2_INITIAL_SEQUENCE_NUMBER \
   "grpc.http2.initial_sequence_number"
+/** Primary user agent: goes at the start of the user-agent metadata
+    sent on each request */
+#define GRPC_ARG_PRIMARY_USER_AGENT_STRING "grpc.primary_user_agent"
+/** Secondary user agent: goes at the end of the user-agent metadata
+    sent on each request */
+#define GRPC_ARG_SECONDARY_USER_AGENT_STRING "grpc.secondary_user_agent"
 
 /** Connectivity state of a channel. */
 typedef enum {
diff --git a/include/grpc/support/port_platform.h b/include/grpc/support/port_platform.h
index a5d1b62702..57fed18cf6 100644
--- a/include/grpc/support/port_platform.h
+++ b/include/grpc/support/port_platform.h
@@ -71,6 +71,7 @@
 
 #if !defined(GPR_NO_AUTODETECT_PLATFORM)
 #if defined(_WIN64) || defined(WIN64)
+#define GPR_PLATFORM_STRING "windows"
 #define GPR_WIN32 1
 #define GPR_ARCH_64 1
 #define GPR_GETPID_IN_PROCESS_H 1
@@ -84,6 +85,7 @@
 #endif
 #define GPR_WINDOWS_CRASH_HANDLER 1
 #elif defined(_WIN32) || defined(WIN32)
+#define GPR_PLATFORM_STRING "windows"
 #define GPR_ARCH_32 1
 #define GPR_WIN32 1
 #define GPR_GETPID_IN_PROCESS_H 1
@@ -97,6 +99,7 @@
 #endif
 #define GPR_WINDOWS_CRASH_HANDLER 1
 #elif defined(ANDROID) || defined(__ANDROID__)
+#define GPR_PLATFORM_STRING "android"
 #define GPR_ANDROID 1
 #define GPR_ARCH_32 1
 #define GPR_CPU_LINUX 1
@@ -117,6 +120,7 @@
 #define GPR_GETPID_IN_UNISTD_H 1
 #define GPR_HAVE_MSG_NOSIGNAL 1
 #elif defined(__linux__)
+#define GPR_PLATFORM_STRING "linux"
 #ifndef _BSD_SOURCE
 #define _BSD_SOURCE
 #endif
@@ -173,9 +177,11 @@
 #define _BSD_SOURCE
 #endif
 #if TARGET_OS_IPHONE
+#define GPR_PLATFORM_STRING "ios"
 #define GPR_CPU_IPHONE 1
 #define GPR_PTHREAD_TLS 1
 #else /* TARGET_OS_IPHONE */
+#define GPR_PLATFORM_STRING "osx"
 #define GPR_CPU_POSIX 1
 #define GPR_GCC_TLS 1
 #endif
@@ -201,6 +207,7 @@
 #define GPR_ARCH_32 1
 #endif /* _LP64 */
 #elif defined(__FreeBSD__)
+#define GPR_PLATFORM_STRING "freebsd"
 #ifndef _BSD_SOURCE
 #define _BSD_SOURCE
 #endif
@@ -232,6 +239,11 @@
 #endif
 #endif /* GPR_NO_AUTODETECT_PLATFORM */
 
+#ifndef GPR_PLATFORM_STRING
+#warning "GPR_PLATFORM_STRING not auto-detected"
+#define GPR_PLATFORM_STRING "unknown"
+#endif
+
 /* For a common case, assume that the platform has a C99-like stdint.h */
 
 #include <stdint.h>
diff --git a/src/core/channel/http_client_filter.c b/src/core/channel/http_client_filter.c
index 63e4912397..bc821b16fa 100644
--- a/src/core/channel/http_client_filter.c
+++ b/src/core/channel/http_client_filter.c
@@ -32,13 +32,17 @@
 
 #include "src/core/channel/http_client_filter.h"
 #include <string.h>
+#include <grpc/support/alloc.h>
 #include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
+#include "src/core/support/string.h"
 
 typedef struct call_data {
   grpc_linked_mdelem method;
   grpc_linked_mdelem scheme;
   grpc_linked_mdelem te_trailers;
   grpc_linked_mdelem content_type;
+  grpc_linked_mdelem user_agent;
   int sent_initial_metadata;
 
   int got_initial_metadata;
@@ -58,6 +62,8 @@ typedef struct channel_data {
   grpc_mdelem *scheme;
   grpc_mdelem *content_type;
   grpc_mdelem *status;
+  /** complete user agent mdelem */
+  grpc_mdelem *user_agent;
 } channel_data;
 
 /* used to silence 'variable not used' warnings */
@@ -115,6 +121,8 @@ static void hc_mutate_op(grpc_call_element *elem,
                                    GRPC_MDELEM_REF(channeld->te_trailers));
       grpc_metadata_batch_add_tail(&op->data.metadata, &calld->content_type,
                                    GRPC_MDELEM_REF(channeld->content_type));
+      grpc_metadata_batch_add_tail(&op->data.metadata, &calld->user_agent,
+                                   GRPC_MDELEM_REF(channeld->user_agent));
       break;
     }
   }
@@ -169,6 +177,55 @@ static const char *scheme_from_args(const grpc_channel_args *args) {
   return "http";
 }
 
+static grpc_mdstr *user_agent_from_args(grpc_mdctx *mdctx,
+                                        const grpc_channel_args *args) {
+  gpr_strvec v;
+  size_t i;
+  int is_first = 1;
+  char *tmp;
+  grpc_mdstr *result;
+
+  gpr_strvec_init(&v);
+
+  for (i = 0; args && i < args->num_args; i++) {
+    if (0 == strcmp(args->args[i].key, GRPC_ARG_PRIMARY_USER_AGENT_STRING)) {
+      if (args->args[i].type != GRPC_ARG_STRING) {
+        gpr_log(GPR_ERROR, "Channel argument '%s' should be a string",
+                GRPC_ARG_PRIMARY_USER_AGENT_STRING);
+      } else {
+        if (!is_first) gpr_strvec_add(&v, gpr_strdup(" "));
+        is_first = 0;
+        gpr_strvec_add(&v, gpr_strdup(args->args[i].value.string));
+      }
+    }
+  }
+
+  gpr_asprintf(&tmp, "%sgrpc-c/%s (%s)", is_first ? "" : " ",
+               grpc_version_string(), GPR_PLATFORM_STRING);
+  is_first = 0;
+  gpr_strvec_add(&v, tmp);
+
+  for (i = 0; args && i < args->num_args; i++) {
+    if (0 == strcmp(args->args[i].key, GRPC_ARG_SECONDARY_USER_AGENT_STRING)) {
+      if (args->args[i].type != GRPC_ARG_STRING) {
+        gpr_log(GPR_ERROR, "Channel argument '%s' should be a string",
+                GRPC_ARG_SECONDARY_USER_AGENT_STRING);
+      } else {
+        if (!is_first) gpr_strvec_add(&v, gpr_strdup(" "));
+        is_first = 0;
+        gpr_strvec_add(&v, gpr_strdup(args->args[i].value.string));
+      }
+    }
+  }
+
+  tmp = gpr_strvec_flatten(&v, NULL);
+  gpr_strvec_destroy(&v);
+  result = grpc_mdstr_from_string(mdctx, tmp);
+  gpr_free(tmp);
+
+  return result;
+}
+
 /* Constructor for channel_data */
 static void init_channel_elem(grpc_channel_element *elem, grpc_channel *master,
                               const grpc_channel_args *args, grpc_mdctx *mdctx,
@@ -189,6 +246,9 @@ static void init_channel_elem(grpc_channel_element *elem, grpc_channel *master,
   channeld->content_type =
       grpc_mdelem_from_strings(mdctx, "content-type", "application/grpc");
   channeld->status = grpc_mdelem_from_strings(mdctx, ":status", "200");
+  channeld->user_agent = grpc_mdelem_from_metadata_strings(
+      mdctx, grpc_mdstr_from_string(mdctx, "user-agent"),
+      user_agent_from_args(mdctx, args));
 }
 
 /* Destructor for channel data */
@@ -201,6 +261,7 @@ static void destroy_channel_elem(grpc_channel_element *elem) {
   GRPC_MDELEM_UNREF(channeld->scheme);
   GRPC_MDELEM_UNREF(channeld->content_type);
   GRPC_MDELEM_UNREF(channeld->status);
+  GRPC_MDELEM_UNREF(channeld->user_agent);
 }
 
 const grpc_channel_filter grpc_http_client_filter = {
diff --git a/src/core/surface/call.h b/src/core/surface/call.h
index 3b6f9c942e..265638d519 100644
--- a/src/core/surface/call.h
+++ b/src/core/surface/call.h
@@ -134,6 +134,10 @@ void grpc_server_log_request_call(char *file, int line,
                                   grpc_completion_queue *cq_for_notification,
                                   void *tag);
 
+void grpc_server_log_shutdown(char *file, int line, gpr_log_severity severity,
+                              grpc_server *server, grpc_completion_queue *cq,
+                              void *tag);
+
 /* Set a context pointer.
    No thread safety guarantees are made wrt this value. */
 void grpc_call_context_set(grpc_call *call, grpc_context_index elem,
@@ -151,6 +155,9 @@ void *grpc_call_context_get(grpc_call *call, grpc_context_index elem);
   grpc_server_log_request_call(sev, server, call, details, initial_metadata, \
                                cq_bound_to_call, cq_for_notifications, tag)
 
+#define GRPC_SERVER_LOG_SHUTDOWN(sev, server, cq, tag) \
+  if (grpc_trace_batch) grpc_server_log_shutdown(sev, server, cq, tag)
+
 gpr_uint8 grpc_call_is_client(grpc_call *call);
 
 #endif /* GRPC_INTERNAL_CORE_SURFACE_CALL_H */
diff --git a/src/core/surface/call_log_batch.c b/src/core/surface/call_log_batch.c
index 997046d954..7bf8cafc24 100644
--- a/src/core/surface/call_log_batch.c
+++ b/src/core/surface/call_log_batch.c
@@ -136,3 +136,11 @@ void grpc_server_log_request_call(char *file, int line,
           "tag=%p)", server, call, details, initial_metadata,
           cq_bound_to_call, cq_for_notification, tag);
 }
+
+void grpc_server_log_shutdown(char *file, int line, gpr_log_severity severity,
+                              grpc_server *server, grpc_completion_queue *cq,
+                              void *tag) {
+  gpr_log(file, line, severity,
+          "grpc_server_shutdown_and_notify(server=%p, cq=%p, tag=%p)", server,
+          cq, tag);
+}
diff --git a/src/core/surface/server.c b/src/core/surface/server.c
index f2d6b11bc7..439452aea2 100644
--- a/src/core/surface/server.c
+++ b/src/core/surface/server.c
@@ -980,6 +980,8 @@ void grpc_server_shutdown_and_notify(grpc_server *server,
   channel_broadcaster broadcaster;
   request_killer reqkill;
 
+  GRPC_SERVER_LOG_SHUTDOWN(GPR_INFO, server, cq, tag);
+
   /* lock, and gather up some stuff to do */
   gpr_mu_lock(&server->mu_global);
   grpc_cq_begin_op(cq);
diff --git a/src/core/transport/chttp2/parsing.c b/src/core/transport/chttp2/parsing.c
index aa32f2e44a..904b9afce7 100644
--- a/src/core/transport/chttp2/parsing.c
+++ b/src/core/transport/chttp2/parsing.c
@@ -588,7 +588,7 @@ static void on_header(void *tp, grpc_mdelem *md) {
   GPR_ASSERT(stream_parsing);
 
   GRPC_CHTTP2_IF_TRACING(gpr_log(
-      GPR_INFO, "HTTP:%d:HDR: %s: %s", stream_parsing->id,
+      GPR_INFO, "HTTP:%d:HDR:%s: %s: %s", stream_parsing->id,
       transport_parsing->is_client ? "CLI" : "SVR",
       grpc_mdstr_as_c_string(md->key), grpc_mdstr_as_c_string(md->value)));
 
diff --git a/src/cpp/client/channel_arguments.cc b/src/cpp/client/channel_arguments.cc
index 4263e377a8..da6602e7af 100644
--- a/src/cpp/client/channel_arguments.cc
+++ b/src/cpp/client/channel_arguments.cc
@@ -33,10 +33,48 @@
 
 #include <grpc++/channel_arguments.h>
 
+#include <grpc/support/log.h>
+
 #include "src/core/channel/channel_args.h"
 
 namespace grpc {
 
+ChannelArguments::ChannelArguments(const ChannelArguments& other)
+    : strings_(other.strings_) {
+  args_.reserve(other.args_.size());
+  auto list_it_dst = strings_.begin();
+  auto list_it_src = other.strings_.begin();
+  for (auto a = other.args_.begin(); a != other.args_.end(); ++a) {
+    grpc_arg ap;
+    ap.type = a->type;
+    GPR_ASSERT(list_it_src->c_str() == a->key);
+    ap.key = const_cast<char*>(list_it_dst->c_str());
+    ++list_it_src;
+    ++list_it_dst;
+    switch (a->type) {
+      case GRPC_ARG_INTEGER:
+        ap.value.integer = a->value.integer;
+        break;
+      case GRPC_ARG_STRING:
+        GPR_ASSERT(list_it_src->c_str() == a->value.string);
+        ap.value.string = const_cast<char*>(list_it_dst->c_str());
+        ++list_it_src;
+        ++list_it_dst;
+        break;
+      case GRPC_ARG_POINTER:
+        ap.value.pointer = a->value.pointer;
+        ap.value.pointer.p = a->value.pointer.copy(ap.value.pointer.p);
+        break;
+    }
+    args_.push_back(ap);
+  }
+}
+
+void ChannelArguments::Swap(ChannelArguments& other) {
+  args_.swap(other.args_);
+  strings_.swap(other.strings_);
+}
+
 void ChannelArguments::SetCompressionAlgorithm(
     grpc_compression_algorithm algorithm) {
   SetInt(GRPC_COMPRESSION_ALGORITHM_ARG, algorithm);
diff --git a/src/cpp/client/create_channel.cc b/src/cpp/client/create_channel.cc
index 510af2bb00..38eeda0dc0 100644
--- a/src/cpp/client/create_channel.cc
+++ b/src/cpp/client/create_channel.cc
@@ -32,9 +32,11 @@
  */
 
 #include <memory>
+#include <sstream>
 
 #include "src/cpp/client/channel.h"
 #include <grpc++/channel_interface.h>
+#include <grpc++/channel_arguments.h>
 #include <grpc++/create_channel.h>
 
 namespace grpc {
@@ -43,7 +45,12 @@ class ChannelArguments;
 std::shared_ptr<ChannelInterface> CreateChannel(
     const grpc::string& target, const std::shared_ptr<Credentials>& creds,
     const ChannelArguments& args) {
-  return creds ? creds->CreateChannel(target, args)
+  ChannelArguments cp_args = args;
+  std::ostringstream user_agent_prefix;
+  user_agent_prefix << "grpc-c++/" << grpc_version_string();
+  cp_args.SetString(GRPC_ARG_PRIMARY_USER_AGENT_STRING,
+                    user_agent_prefix.str());
+  return creds ? creds->CreateChannel(target, cp_args)
                : std::shared_ptr<ChannelInterface>(
                      new Channel(target, grpc_lame_client_channel_create()));
 }
diff --git a/src/php/ext/grpc/server.c b/src/php/ext/grpc/server.c
index c319526e42..8b8d5b2f47 100644
--- a/src/php/ext/grpc/server.c
+++ b/src/php/ext/grpc/server.c
@@ -64,6 +64,7 @@ void free_wrapped_grpc_server(void *object TSRMLS_DC) {
   wrapped_grpc_server *server = (wrapped_grpc_server *)object;
   if (server->wrapped != NULL) {
     grpc_server_shutdown_and_notify(server->wrapped, completion_queue, NULL);
+    grpc_server_cancel_all_calls(server->wrapped);
     grpc_completion_queue_pluck(completion_queue, NULL,
                                 gpr_inf_future(GPR_CLOCK_REALTIME));
     grpc_server_destroy(server->wrapped);
diff --git a/src/php/tests/unit_tests/EndToEndTest.php b/src/php/tests/unit_tests/EndToEndTest.php
index 296873fa8f..2980dca4a7 100755
--- a/src/php/tests/unit_tests/EndToEndTest.php
+++ b/src/php/tests/unit_tests/EndToEndTest.php
@@ -61,7 +61,6 @@ class EndToEndTest extends PHPUnit_Framework_TestCase{
 
     $event = $this->server->requestCall();
     $this->assertSame('dummy_method', $event->method);
-    $this->assertSame([], $event->metadata);
     $server_call = $event->call;
 
     $event = $server_call->startBatch([
@@ -83,7 +82,6 @@ class EndToEndTest extends PHPUnit_Framework_TestCase{
         Grpc\OP_RECV_STATUS_ON_CLIENT => true
                                  ]);
 
-    $this->assertSame([], $event->metadata);
     $status = $event->status;
     $this->assertSame([], $status->metadata);
     $this->assertSame(Grpc\STATUS_OK, $status->code);
diff --git a/src/php/tests/unit_tests/SecureEndToEndTest.php b/src/php/tests/unit_tests/SecureEndToEndTest.php
index 0c18cd3e91..f91c006da5 100755
--- a/src/php/tests/unit_tests/SecureEndToEndTest.php
+++ b/src/php/tests/unit_tests/SecureEndToEndTest.php
@@ -73,7 +73,6 @@ class SecureEndToEndTest extends PHPUnit_Framework_TestCase{
 
     $event = $this->server->requestCall();
     $this->assertSame('dummy_method', $event->method);
-    $this->assertSame([], $event->metadata);
     $server_call = $event->call;
 
     $event = $server_call->startBatch([
diff --git a/src/python/src/grpc/_adapter/_low_test.py b/src/python/src/grpc/_adapter/_low_test.py
index 268e5fe765..a49cd007bf 100644
--- a/src/python/src/grpc/_adapter/_low_test.py
+++ b/src/python/src/grpc/_adapter/_low_test.py
@@ -129,7 +129,10 @@ class InsecureServerInsecureClient(unittest.TestCase):
     self.assertIsInstance(request_event.call, _low.Call)
     self.assertIs(server_request_tag, request_event.tag)
     self.assertEquals(1, len(request_event.results))
-    self.assertEquals(dict(client_initial_metadata), dict(request_event.results[0].initial_metadata))
+    got_initial_metadata = dict(request_event.results[0].initial_metadata)
+    self.assertEquals(
+        dict(client_initial_metadata),
+        dict((x, got_initial_metadata[x]) for x in zip(*client_initial_metadata)[0]))
     self.assertEquals(METHOD, request_event.call_details.method)
     self.assertEquals(HOST, request_event.call_details.host)
     self.assertLess(abs(DEADLINE - request_event.call_details.deadline), DEADLINE_TOLERANCE)
diff --git a/src/python/src/grpc/_links/_transmission_test.py b/src/python/src/grpc/_links/_transmission_test.py
index c5ef1edb25..3eeec03f46 100644
--- a/src/python/src/grpc/_links/_transmission_test.py
+++ b/src/python/src/grpc/_links/_transmission_test.py
@@ -93,8 +93,13 @@ class TransmissionTest(test_cases.TransmissionTest, unittest.TestCase):
   def create_service_completion(self):
     return _intermediary_low.Code.OK, 'An exuberant test "details" message!'
 
-  def assertMetadataEqual(self, original_metadata, transmitted_metadata):
-    self.assertSequenceEqual(original_metadata, transmitted_metadata)
+  def assertMetadataTransmitted(self, original_metadata, transmitted_metadata):
+    # we need to filter out any additional metadata added in transmitted_metadata
+    # since implementations are allowed to add to what is sent (in any position)
+    keys, _ = zip(*original_metadata)
+    self.assertSequenceEqual(
+        original_metadata,
+        [x for x in transmitted_metadata if x[0] in keys])
 
 
 class RoundTripTest(unittest.TestCase):
diff --git a/src/python/src/grpc/framework/interfaces/links/test_cases.py b/src/python/src/grpc/framework/interfaces/links/test_cases.py
index 3ac212ebdf..bf1f09d99d 100644
--- a/src/python/src/grpc/framework/interfaces/links/test_cases.py
+++ b/src/python/src/grpc/framework/interfaces/links/test_cases.py
@@ -161,8 +161,8 @@ class TransmissionTest(object):
     raise NotImplementedError()
 
   @abc.abstractmethod
-  def assertMetadataEqual(self, original_metadata, transmitted_metadata):
-    """Asserts that two metadata objects are equal.
+  def assertMetadataTransmitted(self, original_metadata, transmitted_metadata):
+    """Asserts that transmitted_metadata contains original_metadata.
 
     Args:
       original_metadata: A metadata object used in this test.
@@ -170,7 +170,8 @@ class TransmissionTest(object):
         through the system under test.
 
     Raises:
-      AssertionError: if the two metadata objects are not equal.
+      AssertionError: if the transmitted_metadata object does not contain
+        original_metadata.
     """
     raise NotImplementedError()
 
@@ -239,7 +240,7 @@ class TransmissionTest(object):
         self.assertFalse(initial_metadata_seen)
         self.assertFalse(seen_payloads)
         self.assertFalse(terminal_metadata_seen)
-        self.assertMetadataEqual(initial_metadata, ticket.initial_metadata)
+        self.assertMetadataTransmitted(initial_metadata, ticket.initial_metadata)
         initial_metadata_seen = True
 
       if ticket.payload is not None:
@@ -248,7 +249,7 @@ class TransmissionTest(object):
 
       if ticket.terminal_metadata is not None:
         self.assertFalse(terminal_metadata_seen)
-        self.assertMetadataEqual(terminal_metadata, ticket.terminal_metadata)
+        self.assertMetadataTransmitted(terminal_metadata, ticket.terminal_metadata)
         terminal_metadata_seen = True
     self.assertSequenceEqual(payloads, seen_payloads)
 
diff --git a/src/ruby/spec/generic/rpc_server_spec.rb b/src/ruby/spec/generic/rpc_server_spec.rb
index f2403de77c..0326f6e894 100644
--- a/src/ruby/spec/generic/rpc_server_spec.rb
+++ b/src/ruby/spec/generic/rpc_server_spec.rb
@@ -35,6 +35,14 @@ def load_test_certs
   files.map { |f| File.open(File.join(test_root, f)).read }
 end
 
+def check_md(wanted_md, received_md)
+  wanted_md.zip(received_md).each do |w, r|
+    w.each do |key, value|
+      expect(r[key]).to eq(value)
+    end
+  end
+end
+
 # A test message
 class EchoMsg
   def self.marshal(_o)
@@ -376,7 +384,7 @@ describe GRPC::RpcServer do
         stub = EchoStub.new(@host, **client_opts)
         expect(stub.an_rpc(req, k1: 'v1', k2: 'v2')).to be_a(EchoMsg)
         wanted_md = [{ 'k1' => 'v1', 'k2' => 'v2' }]
-        expect(service.received_md).to eq(wanted_md)
+        check_md(wanted_md, service.received_md)
         @srv.stop
         t.join
       end
@@ -391,7 +399,7 @@ describe GRPC::RpcServer do
         deadline = service.delay + 1.0 # wait for long enough
         expect(stub.an_rpc(req, deadline, k1: 'v1', k2: 'v2')).to be_a(EchoMsg)
         wanted_md = [{ 'k1' => 'v1', 'k2' => 'v2' }]
-        expect(service.received_md).to eq(wanted_md)
+        check_md(wanted_md, service.received_md)
         @srv.stop
         t.join
       end
@@ -443,7 +451,7 @@ describe GRPC::RpcServer do
         expect(stub.an_rpc(req, k1: 'v1', k2: 'v2')).to be_a(EchoMsg)
         wanted_md = [{ 'k1' => 'updated-v1', 'k2' => 'v2',
                        'jwt_aud_uri' => "https://#{@host}/EchoService" }]
-        expect(service.received_md).to eq(wanted_md)
+        check_md(wanted_md, service.received_md)
         @srv.stop
         t.join
       end
@@ -535,7 +543,9 @@ describe GRPC::RpcServer do
           'method' => '/EchoService/an_rpc',
           'connect_k1' => 'connect_v1'
         }
-        expect(op.metadata).to eq(wanted_md)
+        wanted_md.each do |key, value|
+          expect(op.metadata[key]).to eq(value)
+        end
         @srv.stop
         t.join
       end
diff --git a/test/core/end2end/dualstack_socket_test.c b/test/core/end2end/dualstack_socket_test.c
index 7d3568c22e..05ad42ca1f 100644
--- a/test/core/end2end/dualstack_socket_test.c
+++ b/test/core/end2end/dualstack_socket_test.c
@@ -211,6 +211,10 @@ void test_connect(const char *server_host, const char *client_host, int port,
   drain_cq(cq);
   grpc_completion_queue_destroy(cq);
 
+  grpc_metadata_array_destroy(&initial_metadata_recv);
+  grpc_metadata_array_destroy(&trailing_metadata_recv);
+  grpc_metadata_array_destroy(&request_metadata_recv);
+
   grpc_call_details_destroy(&call_details);
   gpr_free(details);
 }
diff --git a/test/cpp/end2end/async_end2end_test.cc b/test/cpp/end2end/async_end2end_test.cc
index 117d8bb9fa..b95bdf6b9b 100644
--- a/test/cpp/end2end/async_end2end_test.cc
+++ b/test/cpp/end2end/async_end2end_test.cc
@@ -415,7 +415,7 @@ TEST_F(AsyncEnd2endTest, ClientInitialMetadataRpc) {
   auto client_initial_metadata = srv_ctx.client_metadata();
   EXPECT_EQ(meta1.second, client_initial_metadata.find(meta1.first)->second);
   EXPECT_EQ(meta2.second, client_initial_metadata.find(meta2.first)->second);
-  EXPECT_EQ(static_cast<size_t>(2), client_initial_metadata.size());
+  EXPECT_GE(client_initial_metadata.size(), static_cast<size_t>(2));
 
   send_response.set_message(recv_request.message());
   response_writer.Finish(send_response, Status::OK, tag(3));
@@ -563,7 +563,7 @@ TEST_F(AsyncEnd2endTest, MetadataRpc) {
   auto client_initial_metadata = srv_ctx.client_metadata();
   EXPECT_EQ(meta1.second, client_initial_metadata.find(meta1.first)->second);
   EXPECT_EQ(meta2.second, client_initial_metadata.find(meta2.first)->second);
-  EXPECT_EQ(static_cast<size_t>(2), client_initial_metadata.size());
+  EXPECT_GE(client_initial_metadata.size(), static_cast<size_t>(2));
 
   srv_ctx.AddInitialMetadata(meta3.first, meta3.second);
   srv_ctx.AddInitialMetadata(meta4.first, meta4.second);
@@ -574,7 +574,7 @@ TEST_F(AsyncEnd2endTest, MetadataRpc) {
   auto server_initial_metadata = cli_ctx.GetServerInitialMetadata();
   EXPECT_EQ(meta3.second, server_initial_metadata.find(meta3.first)->second);
   EXPECT_EQ(meta4.second, server_initial_metadata.find(meta4.first)->second);
-  EXPECT_EQ(static_cast<size_t>(2), server_initial_metadata.size());
+  EXPECT_GE(server_initial_metadata.size(), static_cast<size_t>(2));
 
   send_response.set_message(recv_request.message());
   srv_ctx.AddTrailingMetadata(meta5.first, meta5.second);
@@ -590,7 +590,7 @@ TEST_F(AsyncEnd2endTest, MetadataRpc) {
   auto server_trailing_metadata = cli_ctx.GetServerTrailingMetadata();
   EXPECT_EQ(meta5.second, server_trailing_metadata.find(meta5.first)->second);
   EXPECT_EQ(meta6.second, server_trailing_metadata.find(meta6.first)->second);
-  EXPECT_EQ(static_cast<size_t>(2), server_trailing_metadata.size());
+  EXPECT_GE(server_trailing_metadata.size(), static_cast<size_t>(2));
 }
 }  // namespace
 }  // namespace testing
diff --git a/test/cpp/end2end/end2end_test.cc b/test/cpp/end2end/end2end_test.cc
index 8b4424c735..a865a0e359 100644
--- a/test/cpp/end2end/end2end_test.cc
+++ b/test/cpp/end2end/end2end_test.cc
@@ -249,9 +249,10 @@ class End2endTest : public ::testing::Test {
   void TearDown() GRPC_OVERRIDE { server_->Shutdown(); }
 
   void ResetStub() {
-    std::shared_ptr<ChannelInterface> channel =
-        CreateChannel(server_address_.str(), FakeTransportSecurityCredentials(),
-                      ChannelArguments());
+    ChannelArguments args;
+    args.SetString(GRPC_ARG_SECONDARY_USER_AGENT_STRING, "end2end_test");
+    std::shared_ptr<ChannelInterface> channel = CreateChannel(
+        server_address_.str(), FakeTransportSecurityCredentials(), args);
     stub_ = std::move(grpc::cpp::test::util::TestService::NewStub(channel));
   }
 
diff --git a/test/cpp/qps/qps_test.cc b/test/cpp/qps/qps_test.cc
index 07b4834cc0..7b93443f7c 100644
--- a/test/cpp/qps/qps_test.cc
+++ b/test/cpp/qps/qps_test.cc
@@ -44,8 +44,8 @@
 namespace grpc {
 namespace testing {
 
-static const int WARMUP = 5;
-static const int BENCHMARK = 10;
+static const int WARMUP = 20;
+static const int BENCHMARK = 40;
 
 static void RunQPS() {
   gpr_log(GPR_INFO, "Running QPS test");
@@ -53,8 +53,8 @@ static void RunQPS() {
   ClientConfig client_config;
   client_config.set_client_type(ASYNC_CLIENT);
   client_config.set_enable_ssl(false);
-  client_config.set_outstanding_rpcs_per_channel(1000);
-  client_config.set_client_channels(8);
+  client_config.set_outstanding_rpcs_per_channel(10);
+  client_config.set_client_channels(800);
   client_config.set_payload_size(1);
   client_config.set_async_client_threads(8);
   client_config.set_rpc_type(UNARY);
@@ -62,7 +62,7 @@ static void RunQPS() {
   ServerConfig server_config;
   server_config.set_server_type(ASYNC_SERVER);
   server_config.set_enable_ssl(false);
-  server_config.set_threads(4);
+  server_config.set_threads(8);
 
   const auto result =
       RunScenario(client_config, 1, server_config, 1, WARMUP, BENCHMARK, -2);