diff --git a/AUTHORS b/AUTHORS
index e491a9e7f78..3e130afda2d 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -1 +1,2 @@
 Google Inc.
+WeWork Companies Inc.
diff --git a/include/grpcpp/impl/codegen/callback_common.h b/include/grpcpp/impl/codegen/callback_common.h
index 68c318d2b44..8b3ad66a8d3 100644
--- a/include/grpcpp/impl/codegen/callback_common.h
+++ b/include/grpcpp/impl/codegen/callback_common.h
@@ -35,6 +35,10 @@ class CQCallbackInterface;
 namespace grpc {
 namespace internal {
 
+// The contract on these tags is that they are single-shot. They must be
+// constructed and then fired at exactly one point. There is no expectation
+// that they can be reused without reconstruction.
+
 class CallbackWithStatusTag {
  public:
   // always allocated against a call arena, no memory free required
diff --git a/src/compiler/ruby_generator.cc b/src/compiler/ruby_generator.cc
index c7af9c38fad..e39d8be5d41 100644
--- a/src/compiler/ruby_generator.cc
+++ b/src/compiler/ruby_generator.cc
@@ -160,12 +160,20 @@ grpc::string GetServices(const FileDescriptor* file) {
       return output;
     }
 
+    std::string package_name;
+
+    if (file->options().has_ruby_package()) {
+      package_name = file->options().ruby_package();
+    } else {
+      package_name = file->package();
+    }
+
     // Write out a file header.
     std::map<grpc::string, grpc::string> header_comment_vars = ListToDict({
         "file.name",
         file->name(),
         "file.package",
-        file->package(),
+        package_name,
     });
     out.Print("# Generated by the protocol buffer compiler.  DO NOT EDIT!\n");
     out.Print(header_comment_vars,
@@ -190,7 +198,7 @@ grpc::string GetServices(const FileDescriptor* file) {
 
     // Write out services within the modules
     out.Print("\n");
-    std::vector<grpc::string> modules = Split(file->package(), '.');
+    std::vector<grpc::string> modules = Split(package_name, '.');
     for (size_t i = 0; i < modules.size(); ++i) {
       std::map<grpc::string, grpc::string> module_vars = ListToDict({
           "module.name",
diff --git a/src/core/ext/filters/client_channel/parse_address.cc b/src/core/ext/filters/client_channel/parse_address.cc
index b94429e207e..707beb88769 100644
--- a/src/core/ext/filters/client_channel/parse_address.cc
+++ b/src/core/ext/filters/client_channel/parse_address.cc
@@ -129,30 +129,37 @@ bool grpc_parse_ipv6_hostport(const char* hostport, grpc_resolved_address* addr,
     size_t host_without_scope_len = static_cast<size_t>(host_end - host);
     uint32_t sin6_scope_id = 0;
     if (host_without_scope_len > GRPC_INET6_ADDRSTRLEN) {
-      gpr_log(GPR_ERROR,
-              "invalid ipv6 address length %zu. Length cannot be greater than "
-              "GRPC_INET6_ADDRSTRLEN i.e %d)",
-              host_without_scope_len, GRPC_INET6_ADDRSTRLEN);
+      if (log_errors) {
+        gpr_log(
+            GPR_ERROR,
+            "invalid ipv6 address length %zu. Length cannot be greater than "
+            "GRPC_INET6_ADDRSTRLEN i.e %d)",
+            host_without_scope_len, GRPC_INET6_ADDRSTRLEN);
+      }
       goto done;
     }
     strncpy(host_without_scope, host, host_without_scope_len);
     host_without_scope[host_without_scope_len] = '\0';
     if (grpc_inet_pton(GRPC_AF_INET6, host_without_scope, &in6->sin6_addr) ==
         0) {
-      gpr_log(GPR_ERROR, "invalid ipv6 address: '%s'", host_without_scope);
+      if (log_errors) {
+        gpr_log(GPR_ERROR, "invalid ipv6 address: '%s'", host_without_scope);
+      }
       goto done;
     }
     if (gpr_parse_bytes_to_uint32(host_end + 1,
                                   strlen(host) - host_without_scope_len - 1,
                                   &sin6_scope_id) == 0) {
-      gpr_log(GPR_ERROR, "invalid ipv6 scope id: '%s'", host_end + 1);
+      if (log_errors) {
+        gpr_log(GPR_ERROR, "invalid ipv6 scope id: '%s'", host_end + 1);
+      }
       goto done;
     }
     // Handle "sin6_scope_id" being type "u_long". See grpc issue #10027.
     in6->sin6_scope_id = sin6_scope_id;
   } else {
     if (grpc_inet_pton(GRPC_AF_INET6, host, &in6->sin6_addr) == 0) {
-      gpr_log(GPR_ERROR, "invalid ipv6 address: '%s'", host);
+      if (log_errors) gpr_log(GPR_ERROR, "invalid ipv6 address: '%s'", host);
       goto done;
     }
   }
diff --git a/src/core/lib/surface/call.cc b/src/core/lib/surface/call.cc
index 11b438f5dc8..a9349afa68a 100644
--- a/src/core/lib/surface/call.cc
+++ b/src/core/lib/surface/call.cc
@@ -207,7 +207,7 @@ struct grpc_call {
       grpc_server* server;
     } server;
   } final_op;
-  grpc_error* status_error;
+  gpr_atm status_error;
 
   /* recv_state can contain one of the following values:
      RECV_NONE :                 :  no initial metadata and messages received
@@ -519,10 +519,12 @@ static void destroy_call(void* call, grpc_error* error) {
     GRPC_CQ_INTERNAL_UNREF(c->cq, "bind");
   }
 
-  grpc_error_get_status(c->status_error, c->send_deadline,
+  grpc_error* status_error =
+      reinterpret_cast<grpc_error*>(gpr_atm_acq_load(&c->status_error));
+  grpc_error_get_status(status_error, c->send_deadline,
                         &c->final_info.final_status, nullptr, nullptr,
                         &(c->final_info.error_string));
-  GRPC_ERROR_UNREF(c->status_error);
+  GRPC_ERROR_UNREF(status_error);
   c->final_info.stats.latency =
       gpr_time_sub(gpr_now(GPR_CLOCK_MONOTONIC), c->start_time);
 
@@ -705,7 +707,7 @@ static void set_final_status(grpc_call* call, grpc_error* error) {
                           call->final_op.client.error_string);
     // explicitly take a ref
     grpc_slice_ref_internal(*call->final_op.client.status_details);
-    call->status_error = error;
+    gpr_atm_rel_store(&call->status_error, reinterpret_cast<gpr_atm>(error));
     grpc_core::channelz::ChannelNode* channelz_channel =
         grpc_channel_get_channelz_node(call->channel);
     if (channelz_channel != nullptr) {
@@ -717,7 +719,9 @@ static void set_final_status(grpc_call* call, grpc_error* error) {
     }
   } else {
     *call->final_op.server.cancelled =
-        error != GRPC_ERROR_NONE || call->status_error != GRPC_ERROR_NONE;
+        error != GRPC_ERROR_NONE ||
+        reinterpret_cast<grpc_error*>(gpr_atm_acq_load(&call->status_error)) !=
+            GRPC_ERROR_NONE;
     grpc_core::channelz::ServerNode* channelz_server =
         grpc_server_get_channelz_node(call->final_op.server.server);
     if (channelz_server != nullptr) {
@@ -1686,7 +1690,8 @@ static grpc_call_error call_start_batch(grpc_call* call, const grpc_op* ops,
           }
         }
 
-        call->status_error = status_error;
+        gpr_atm_rel_store(&call->status_error,
+                          reinterpret_cast<gpr_atm>(status_error));
         if (!prepare_application_metadata(
                 call,
                 static_cast<int>(
diff --git a/src/cpp/common/callback_common.cc b/src/cpp/common/callback_common.cc
index ae47901f1be..fa586286d1c 100644
--- a/src/cpp/common/callback_common.cc
+++ b/src/cpp/common/callback_common.cc
@@ -26,8 +26,21 @@
 
 namespace grpc {
 namespace internal {
-
 namespace {
+
+template <class Func, class Arg>
+void CatchingCallback(Func&& func, Arg&& arg) {
+#if GRPC_ALLOW_EXCEPTIONS
+  try {
+    func(arg);
+  } catch (...) {
+    // nothing to return or change here, just don't crash the library
+  }
+#else   // GRPC_ALLOW_EXCEPTIONS
+  func(arg);
+#endif  // GRPC_ALLOW_EXCEPTIONS
+}
+
 class CallbackWithSuccessImpl : public grpc_core::CQCallbackInterface {
  public:
   static void operator delete(void* ptr, std::size_t size) {
@@ -52,8 +65,11 @@ class CallbackWithSuccessImpl : public grpc_core::CQCallbackInterface {
     bool new_ok = ok;
     GPR_ASSERT(parent_->ops()->FinalizeResult(&ignored, &new_ok));
     GPR_ASSERT(ignored == parent_->ops());
-    func_(ok);
-    func_ = nullptr;  // release the function
+
+    // Last use of func_ or ok, so ok to move them out for rvalue call above
+    CatchingCallback(std::move(func_), std::move(ok));
+
+    func_ = nullptr;  // reset to clear this out for sure
     grpc_call_unref(call_);
   }
 
@@ -88,8 +104,10 @@ class CallbackWithStatusImpl : public grpc_core::CQCallbackInterface {
     GPR_ASSERT(parent_->ops()->FinalizeResult(&ignored, &ok));
     GPR_ASSERT(ignored == parent_->ops());
 
-    func_(status_);
-    func_ = nullptr;  // release the function
+    // Last use of func_ or status_, so ok to move them out
+    CatchingCallback(std::move(func_), std::move(status_));
+
+    func_ = nullptr;  // reset to clear this out for sure
     grpc_call_unref(call_);
   }
   Status* status_ptr() { return &status_; }
diff --git a/src/cpp/ext/filters/census/server_filter.cc b/src/cpp/ext/filters/census/server_filter.cc
index c7c62eefe51..b5f3d5a13a7 100644
--- a/src/cpp/ext/filters/census/server_filter.cc
+++ b/src/cpp/ext/filters/census/server_filter.cc
@@ -93,7 +93,7 @@ void CensusServerCallData::OnDoneRecvInitialMetadataCb(void* user_data,
     FilterInitialMetadata(initial_metadata, &sml);
     calld->path_ = grpc_slice_ref_internal(sml.path);
     calld->method_ = GetMethod(&calld->path_);
-    calld->qualified_method_ = StrCat("Recv.", calld->method_);
+    calld->qualified_method_ = absl::StrCat("Recv.", calld->method_);
     const char* tracing_str =
         GRPC_SLICE_IS_EMPTY(sml.tracing_slice)
             ? ""
diff --git a/src/proto/grpc/testing/package_options.proto b/src/proto/grpc/testing/package_options.proto
new file mode 100644
index 00000000000..e7ecf8c196a
--- /dev/null
+++ b/src/proto/grpc/testing/package_options.proto
@@ -0,0 +1,28 @@
+// Copyright 2018 gRPC authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+syntax = "proto3";
+
+package grpc.testing;
+
+// For sanity checking package definitions
+option ruby_package = "Grpc.Testing.Package.Options";
+
+message TestRequest { }
+
+message TestResponse { }
+
+service TestService {
+  rpc GetTest(TestRequest) returns (TestResponse) { }
+}
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pyx.pxi b/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pyx.pxi
index 38fd9e78b2d..63048e8da0d 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pyx.pxi
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/credentials.pyx.pxi
@@ -144,8 +144,14 @@ cdef class SSLChannelCredentials(ChannelCredentials):
       return grpc_ssl_credentials_create(
           c_pem_root_certificates, NULL, NULL, NULL)
     else:
-      c_pem_key_certificate_pair.private_key = self._private_key
-      c_pem_key_certificate_pair.certificate_chain = self._certificate_chain
+      if self._private_key:
+        c_pem_key_certificate_pair.private_key = self._private_key
+      else:
+        c_pem_key_certificate_pair.private_key = NULL
+      if self._certificate_chain:
+        c_pem_key_certificate_pair.certificate_chain = self._certificate_chain
+      else:
+        c_pem_key_certificate_pair.certificate_chain = NULL
       return grpc_ssl_credentials_create(
           c_pem_root_certificates, &c_pem_key_certificate_pair, NULL, NULL)
 
diff --git a/src/ruby/ext/grpc/rb_call.c b/src/ruby/ext/grpc/rb_call.c
index b6c07914693..fc641dae801 100644
--- a/src/ruby/ext/grpc/rb_call.c
+++ b/src/ruby/ext/grpc/rb_call.c
@@ -819,6 +819,7 @@ static VALUE grpc_rb_call_run_batch(VALUE self, VALUE ops_hash) {
   unsigned write_flag = 0;
   void* tag = (void*)&st;
 
+  grpc_ruby_fork_guard();
   if (RTYPEDDATA_DATA(self) == NULL) {
     rb_raise(grpc_rb_eCallError, "Cannot run batch on closed call");
     return Qnil;
diff --git a/src/ruby/ext/grpc/rb_channel.c b/src/ruby/ext/grpc/rb_channel.c
index 3f0dc530cfe..6d4b2293a24 100644
--- a/src/ruby/ext/grpc/rb_channel.c
+++ b/src/ruby/ext/grpc/rb_channel.c
@@ -217,6 +217,7 @@ static VALUE grpc_rb_channel_init(int argc, VALUE* argv, VALUE self) {
   MEMZERO(&args, grpc_channel_args, 1);
 
   grpc_ruby_once_init();
+  grpc_ruby_fork_guard();
   rb_thread_call_without_gvl(
       wait_until_channel_polling_thread_started_no_gil,
       &stop_waiting_for_thread_start,
@@ -374,6 +375,7 @@ static VALUE grpc_rb_channel_watch_connectivity_state(VALUE self,
   watch_state_stack stack;
   void* op_success = 0;
 
+  grpc_ruby_fork_guard();
   TypedData_Get_Struct(self, grpc_rb_channel, &grpc_channel_data_type, wrapper);
 
   if (wrapper->bg_wrapped == NULL) {
@@ -415,6 +417,7 @@ static VALUE grpc_rb_channel_create_call(VALUE self, VALUE parent, VALUE mask,
   grpc_slice* host_slice_ptr = NULL;
   char* tmp_str = NULL;
 
+  grpc_ruby_fork_guard();
   if (host != Qnil) {
     host_slice =
         grpc_slice_from_copied_buffer(RSTRING_PTR(host), RSTRING_LEN(host));
diff --git a/src/ruby/ext/grpc/rb_grpc.c b/src/ruby/ext/grpc/rb_grpc.c
index f065a857db8..872aed0cfce 100644
--- a/src/ruby/ext/grpc/rb_grpc.c
+++ b/src/ruby/ext/grpc/rb_grpc.c
@@ -23,9 +23,13 @@
 
 #include <math.h>
 #include <ruby/vm.h>
+#include <stdbool.h>
 #include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
 
 #include <grpc/grpc.h>
+#include <grpc/support/log.h>
 #include <grpc/support/time.h>
 #include "rb_call.h"
 #include "rb_call_credentials.h"
@@ -255,7 +259,26 @@ static void Init_grpc_time_consts() {
   id_tv_nsec = rb_intern("tv_nsec");
 }
 
-static void grpc_rb_shutdown(void) { grpc_shutdown(); }
+#if GPR_WINDOWS
+static void grpc_ruby_set_init_pid(void) {}
+static bool grpc_ruby_forked_after_init(void) { return false; }
+#else
+static pid_t grpc_init_pid;
+
+static void grpc_ruby_set_init_pid(void) {
+  GPR_ASSERT(grpc_init_pid == 0);
+  grpc_init_pid = getpid();
+}
+
+static bool grpc_ruby_forked_after_init(void) {
+  GPR_ASSERT(grpc_init_pid != 0);
+  return grpc_init_pid != getpid();
+}
+#endif
+
+static void grpc_rb_shutdown(void) {
+  if (!grpc_ruby_forked_after_init()) grpc_shutdown();
+}
 
 /* Initialize the GRPC module structs */
 
@@ -276,10 +299,17 @@ VALUE sym_metadata = Qundef;
 static gpr_once g_once_init = GPR_ONCE_INIT;
 
 static void grpc_ruby_once_init_internal() {
+  grpc_ruby_set_init_pid();
   grpc_init();
   atexit(grpc_rb_shutdown);
 }
 
+void grpc_ruby_fork_guard() {
+  if (grpc_ruby_forked_after_init()) {
+    rb_raise(rb_eRuntimeError, "grpc cannot be used before and after forking");
+  }
+}
+
 static VALUE bg_thread_init_rb_mu = Qundef;
 static int bg_thread_init_done = 0;
 
diff --git a/src/ruby/ext/grpc/rb_grpc.h b/src/ruby/ext/grpc/rb_grpc.h
index 577902319ed..4118435ecf7 100644
--- a/src/ruby/ext/grpc/rb_grpc.h
+++ b/src/ruby/ext/grpc/rb_grpc.h
@@ -69,4 +69,6 @@ gpr_timespec grpc_rb_time_timeval(VALUE time, int interval);
 
 void grpc_ruby_once_init();
 
+void grpc_ruby_fork_guard();
+
 #endif /* GRPC_RB_H_ */
diff --git a/src/ruby/ext/grpc/rb_server.c b/src/ruby/ext/grpc/rb_server.c
index 88e6a0cfd56..2931f344092 100644
--- a/src/ruby/ext/grpc/rb_server.c
+++ b/src/ruby/ext/grpc/rb_server.c
@@ -243,6 +243,8 @@ static VALUE grpc_rb_server_request_call(VALUE self) {
 static VALUE grpc_rb_server_start(VALUE self) {
   grpc_rb_server* s = NULL;
   TypedData_Get_Struct(self, grpc_rb_server, &grpc_rb_server_data_type, s);
+
+  grpc_ruby_fork_guard();
   if (s->wrapped == NULL) {
     rb_raise(rb_eRuntimeError, "destroyed!");
   } else {
diff --git a/src/ruby/lib/grpc/generic/rpc_server.rb b/src/ruby/lib/grpc/generic/rpc_server.rb
index 838ac45927b..3b5a0ce27f3 100644
--- a/src/ruby/lib/grpc/generic/rpc_server.rb
+++ b/src/ruby/lib/grpc/generic/rpc_server.rb
@@ -136,7 +136,7 @@ module GRPC
         begin
           blk, args = worker_queue.pop
           blk.call(*args)
-        rescue StandardError => e
+        rescue StandardError, GRPC::Core::CallError => e
           GRPC.logger.warn('Error in worker thread')
           GRPC.logger.warn(e)
         end
diff --git a/src/ruby/spec/channel_spec.rb b/src/ruby/spec/channel_spec.rb
index 3c9eca47ecc..adba6db99cf 100644
--- a/src/ruby/spec/channel_spec.rb
+++ b/src/ruby/spec/channel_spec.rb
@@ -13,6 +13,7 @@
 # limitations under the License.
 
 require 'spec_helper'
+require 'English'
 
 def load_test_certs
   test_root = File.join(File.dirname(__FILE__), 'testdata')
@@ -27,6 +28,28 @@ describe GRPC::Core::Channel do
     GRPC::Core::ChannelCredentials.new(load_test_certs[0])
   end
 
+  def fork_with_propagated_error_message
+    pipe_read, pipe_write = IO.pipe
+    pid = fork do
+      pipe_read.close
+      begin
+        yield
+      rescue => exc
+        pipe_write.syswrite(exc.message)
+      end
+      pipe_write.close
+    end
+    pipe_write.close
+
+    exc_message = pipe_read.read
+    Process.wait(pid)
+
+    unless $CHILD_STATUS.success?
+      raise "forked process failed with #{$CHILD_STATUS}"
+    end
+    raise exc_message unless exc_message.empty?
+  end
+
   shared_examples '#new' do
     it 'take a host name without channel args' do
       blk = proc do
@@ -79,6 +102,14 @@ describe GRPC::Core::Channel do
       blk = construct_with_args(args)
       expect(&blk).to_not raise_error
     end
+
+    it 'raises if grpc was initialized in another process' do
+      blk = construct_with_args({})
+      expect(&blk).not_to raise_error
+      expect do
+        fork_with_propagated_error_message(&blk)
+      end.to raise_error(RuntimeError, 'grpc cannot be used before and after forking')
+    end
   end
 
   describe '#new for secure channels' do
@@ -121,6 +152,19 @@ describe GRPC::Core::Channel do
       end
       expect(&blk).to raise_error(RuntimeError)
     end
+
+    it 'raises if grpc was initialized in another process' do
+      ch = GRPC::Core::Channel.new(fake_host, nil, :this_channel_is_insecure)
+
+      deadline = Time.now + 5
+
+      blk = proc do
+        fork_with_propagated_error_message do
+          ch.create_call(nil, nil, 'dummy_method', nil, deadline)
+        end
+      end
+      expect(&blk).to raise_error(RuntimeError, 'grpc cannot be used before and after forking')
+    end
   end
 
   describe '#destroy' do
diff --git a/src/ruby/spec/pb/codegen/package_option_spec.rb b/src/ruby/spec/pb/codegen/package_option_spec.rb
new file mode 100644
index 00000000000..46d23cd6518
--- /dev/null
+++ b/src/ruby/spec/pb/codegen/package_option_spec.rb
@@ -0,0 +1,53 @@
+# Copyright 2018 gRPC authors.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+require 'spec_helper'
+require 'open3'
+require 'tmpdir'
+
+describe 'Code Generation Options' do
+  it 'should generate and respect package options' do
+    fail 'CONFIG env variable unexpectedly unset' unless ENV['CONFIG']
+    bins_sub_dir = ENV['CONFIG']
+
+    src_dir = File.join(File.dirname(__FILE__), '..', '..', '..', '..')
+    pb_dir = File.join(src_dir, 'proto')
+    bins_dir = File.join(src_dir, '..', 'bins', bins_sub_dir)
+
+    plugin = File.join(bins_dir, 'grpc_ruby_plugin')
+    protoc = File.join(bins_dir, 'protobuf', 'protoc')
+
+    # Generate the service from the proto
+    Dir.mktmpdir(nil, File.dirname(__FILE__)) do |tmp_dir|
+      gen_file = system(protoc,
+                        '-I.',
+                        'grpc/testing/package_options.proto',
+                        "--grpc_out=#{tmp_dir}", # generate the service
+                        "--ruby_out=#{tmp_dir}", # generate the definitions
+                        "--plugin=protoc-gen-grpc=#{plugin}",
+                        chdir: pb_dir,
+                        out: File::NULL)
+
+      expect(gen_file).to be_truthy
+      begin
+        $LOAD_PATH.push(tmp_dir)
+        expect { Grpc::Testing::Package::Options::TestService::Service }.to raise_error(NameError)
+        expect(require('grpc/testing/package_options_services_pb')).to be_truthy
+        expect { Grpc::Testing::Package::Options::TestService::Service }.to_not raise_error
+      ensure
+        $LOAD_PATH.delete(tmp_dir)
+      end
+    end
+  end
+end
diff --git a/test/cpp/end2end/client_callback_end2end_test.cc b/test/cpp/end2end/client_callback_end2end_test.cc
index 75b896b33d8..3b492090dd1 100644
--- a/test/cpp/end2end/client_callback_end2end_test.cc
+++ b/test/cpp/end2end/client_callback_end2end_test.cc
@@ -64,7 +64,7 @@ class ClientCallbackEnd2endTest : public ::testing::Test {
     }
   }
 
-  void SendRpcs(int num_rpcs) {
+  void SendRpcs(int num_rpcs, bool maybe_except) {
     const grpc::string kMethodName("/grpc.testing.EchoTestService/Echo");
     grpc::string test_string("");
     for (int i = 0; i < num_rpcs; i++) {
@@ -82,7 +82,7 @@ class ClientCallbackEnd2endTest : public ::testing::Test {
       bool done = false;
       stub_->experimental().UnaryCall(
           &cli_ctx, kMethodName, send_buf.get(), &recv_buf,
-          [&request, &recv_buf, &done, &mu, &cv](Status s) {
+          [&request, &recv_buf, &done, &mu, &cv, maybe_except](Status s) {
             GPR_ASSERT(s.ok());
 
             EchoResponse response;
@@ -91,6 +91,11 @@ class ClientCallbackEnd2endTest : public ::testing::Test {
             std::lock_guard<std::mutex> l(mu);
             done = true;
             cv.notify_one();
+#if GRPC_ALLOW_EXCEPTIONS
+            if (maybe_except) {
+              throw - 1;
+            }
+#endif
           });
       std::unique_lock<std::mutex> l(mu);
       while (!done) {
@@ -107,14 +112,21 @@ class ClientCallbackEnd2endTest : public ::testing::Test {
 
 TEST_F(ClientCallbackEnd2endTest, SimpleRpc) {
   ResetStub();
-  SendRpcs(1);
+  SendRpcs(1, false);
 }
 
 TEST_F(ClientCallbackEnd2endTest, SequentialRpcs) {
   ResetStub();
-  SendRpcs(10);
+  SendRpcs(10, false);
 }
 
+#if GRPC_ALLOW_EXCEPTIONS
+TEST_F(ClientCallbackEnd2endTest, ExceptingRpc) {
+  ResetStub();
+  SendRpcs(10, true);
+}
+#endif
+
 }  // namespace
 }  // namespace testing
 }  // namespace grpc
diff --git a/test/cpp/microbenchmarks/helpers.cc b/test/cpp/microbenchmarks/helpers.cc
index e4ba37e2d6a..bce72985dc2 100644
--- a/test/cpp/microbenchmarks/helpers.cc
+++ b/test/cpp/microbenchmarks/helpers.cc
@@ -38,6 +38,7 @@ void TrackCounters::AddLabel(const grpc::string& label) {
 }
 
 void TrackCounters::AddToLabel(std::ostream& out, benchmark::State& state) {
+#ifdef GRPC_COLLECT_STATS
   grpc_stats_data stats_end;
   grpc_stats_collect(&stats_end);
   grpc_stats_data stats;
@@ -53,6 +54,7 @@ void TrackCounters::AddToLabel(std::ostream& out, benchmark::State& state) {
         << " " << grpc_stats_histogram_name[i] << "-99p:"
         << grpc_stats_histo_percentile(&stats, (grpc_stats_histograms)i, 99.0);
   }
+#endif
 #ifdef GPR_LOW_LEVEL_COUNTERS
   grpc_memory_counters counters_at_end = grpc_memory_counters_snapshot();
   out << " locks/iter:"
diff --git a/test/distrib/csharp/run_distrib_test.sh b/test/distrib/csharp/run_distrib_test.sh
index f9371410e7b..61924b91df8 100755
--- a/test/distrib/csharp/run_distrib_test.sh
+++ b/test/distrib/csharp/run_distrib_test.sh
@@ -21,7 +21,8 @@ unzip -o "$EXTERNAL_GIT_ROOT/input_artifacts/csharp_nugets_windows_dotnetcli.zip
 
 ./update_version.sh auto
 
-nuget restore
+# Retry "nuget restore" to work around https://github.com/grpc/grpc/issues/16312
+nuget restore || nuget restore || nuget restore
 
 xbuild DistribTest.sln
 
diff --git a/tools/interop_matrix/client_matrix.py b/tools/interop_matrix/client_matrix.py
index c55789f27ee..15b53d1716b 100644
--- a/tools/interop_matrix/client_matrix.py
+++ b/tools/interop_matrix/client_matrix.py
@@ -99,6 +99,9 @@ LANG_RELEASE_MATRIX = {
         {
             'v1.14.1': None
         },
+        {
+            'v1.15.0': None
+        },
     ],
     'go': [
         {
@@ -231,6 +234,9 @@ LANG_RELEASE_MATRIX = {
         {
             'v1.14.1': None
         },
+        {
+            'v1.15.0': None
+        },
     ],
     'node': [
         {
@@ -319,6 +325,9 @@ LANG_RELEASE_MATRIX = {
         {
             'v1.14.1': None
         },
+        {
+            'v1.15.0': None
+        },
     ],
     'php': [
         {
@@ -363,6 +372,9 @@ LANG_RELEASE_MATRIX = {
         {
             'v1.14.1': None
         },
+        {
+            'v1.15.0': None
+        },
     ],
     'csharp': [
         {
@@ -412,6 +424,9 @@ LANG_RELEASE_MATRIX = {
         {
             'v1.14.1': None
         },
+        {
+            'v1.15.0': None
+        },
     ],
 }
 
diff --git a/tools/run_tests/run_tests_matrix.py b/tools/run_tests/run_tests_matrix.py
index 0af9e0cbbe1..1bbec94ee12 100755
--- a/tools/run_tests/run_tests_matrix.py
+++ b/tools/run_tests/run_tests_matrix.py
@@ -53,12 +53,7 @@ def _safe_report_name(name):
 
 
 def _report_filename(name):
-    """Generates report file name"""
-    return 'report_%s_%s' % (_safe_report_name(name), _REPORT_SUFFIX)
-
-
-def _report_filename_internal_ci(name):
-    """Generates report file name that leads to better presentation by internal CI"""
+    """Generates report file name with directory structure that leads to better presentation by internal CI"""
     return '%s/%s' % (_safe_report_name(name), _REPORT_SUFFIX)
 
 
@@ -507,8 +502,9 @@ if __name__ == "__main__":
         default=False,
         action='store_const',
         const=True,
-        help='Put reports into subdirectories to improve presentation of '
-        'results by Internal CI.')
+        help=
+        '(Deprecated, has no effect) Put reports into subdirectories to improve presentation of '
+        'results by Kokoro.')
     argp.add_argument(
         '--bq_result_table',
         default='',
@@ -517,9 +513,6 @@ if __name__ == "__main__":
         help='Upload test results to a specified BQ table.')
     args = argp.parse_args()
 
-    if args.internal_ci:
-        _report_filename = _report_filename_internal_ci  # override the function
-
     extra_args = []
     if args.build_only:
         extra_args.append('--build_only')