Merge branch 'master' into base_log

119 files changed, 933 insertions, 585 deletions

diff --git a/Rakefile b/Rakefile
index 3a30920fea..f208a24fd3 100755
--- a/Rakefile
+++ b/Rakefile
@@ -3,6 +3,7 @@ require 'rake/extensiontask'
 require 'rspec/core/rake_task'
 require 'rubocop/rake_task'
 require 'bundler/gem_tasks'
+require 'fileutils'
 
 load 'tools/distrib/docker_for_windows.rb'
 
@@ -23,7 +24,11 @@ Rake::ExtensionTask.new('grpc_c', spec) do |ext|
   ext.ext_dir = File.join('src', 'ruby', 'ext', 'grpc')
   ext.lib_dir = File.join('src', 'ruby', 'lib', 'grpc')
   ext.cross_compile = true
-  ext.cross_platform = ['x86-mingw32', 'x64-mingw32']
+  ext.cross_platform = [
+    'x86-mingw32', 'x64-mingw32',
+    'x86_64-linux', 'x86-linux',
+    'universal-darwin'
+  ]
   ext.cross_compiling do |spec|
     spec.files = %w( etc/roots.pem grpc_c.32.ruby grpc_c.64.ruby )
     spec.files += Dir.glob('src/ruby/bin/**/*')
@@ -91,11 +96,18 @@ task 'dlls' do
 
 end
 
-desc 'Build the gem file under rake_compiler_dock'
-task 'gem:windows' do
+desc 'Build the native gem file under rake_compiler_dock'
+task 'gem:native' do
   verbose = ENV['V'] || '0'
 
-  docker_for_windows "bundle && rake cross native gem RUBY_CC_VERSION=2.3.0:2.2.2:2.1.6:2.0.0 V=#{verbose}"
+  if RUBY_PLATFORM =~ /darwin/
+    FileUtils.touch 'grpc_c.32.ruby'
+    FileUtils.touch 'grpc_c.64.ruby'
+    system "rake cross native gem RUBY_CC_VERSION=2.3.0:2.2.2:2.1.5:2.0.0 V=#{verbose}"
+  else
+    Rake::Task['dlls'].execute
+    docker_for_windows "bundle && rake cross native gem RUBY_CC_VERSION=2.3.0:2.2.2:2.1.5:2.0.0 V=#{verbose}"
+  end
 end
 
 # Define dependencies between the suites.
@@ -105,8 +117,6 @@ task 'suite:bidi' => 'suite:wrapper'
 task 'suite:server' => 'suite:wrapper'
 task 'suite:pb' => 'suite:server'
 
-task 'gem:windows' => 'dlls'
-
 desc 'Compiles the gRPC extension then runs all the tests'
 task all: ['suite:idiomatic', 'suite:bidi', 'suite:pb', 'suite:server']
 task default: :all
diff --git a/examples/node/greeter_client.js b/examples/node/greeter_client.js
index e0b89bd376..9b4b0a7782 100644
--- a/examples/node/greeter_client.js
+++ b/examples/node/greeter_client.js
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -33,7 +33,7 @@
 
 var PROTO_PATH = __dirname + '/helloworld.proto';
 
-var grpc = require('../../');
+var grpc = require('grpc');
 var hello_proto = grpc.load(PROTO_PATH).helloworld;
 
 function main() {
diff --git a/examples/node/greeter_server.js b/examples/node/greeter_server.js
index 3600c8bfbf..2712b3dd3a 100644
--- a/examples/node/greeter_server.js
+++ b/examples/node/greeter_server.js
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -33,7 +33,7 @@
 
 var PROTO_PATH = __dirname + '/helloworld.proto';
 
-var grpc = require('../../');
+var grpc = require('grpc');
 var hello_proto = grpc.load(PROTO_PATH).helloworld;
 
 /**
diff --git a/examples/node/package.json b/examples/node/package.json
new file mode 100644
index 0000000000..65c5789ed7
--- /dev/null
+++ b/examples/node/package.json
@@ -0,0 +1,7 @@
+{
+  "name": "grpc-examples",
+  "version": "0.1.0",
+  "dependencies": {
+    "grpc": "0.12.0"
+  }
+}
diff --git a/examples/node/route_guide/route_guide_client.js b/examples/node/route_guide/route_guide_client.js
index edeca6ff55..e38a21f422 100644
--- a/examples/node/route_guide/route_guide_client.js
+++ b/examples/node/route_guide/route_guide_client.js
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -30,13 +30,13 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */
- 
+
 var async = require('async');
 var fs = require('fs');
 var parseArgs = require('minimist');
 var path = require('path');
 var _ = require('lodash');
-var grpc = require('../../../');
+var grpc = require('grpc');
 var routeguide = grpc.load(__dirname + '/route_guide.proto').routeguide;
 var client = new routeguide.RouteGuide('localhost:50051',
                                        grpc.Credentials.createInsecure());
diff --git a/examples/node/route_guide/route_guide_server.js b/examples/node/route_guide/route_guide_server.js
index 2090a6a1d2..06cf2925e1 100644
--- a/examples/node/route_guide/route_guide_server.js
+++ b/examples/node/route_guide/route_guide_server.js
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -30,12 +30,12 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */
- 
+
 var fs = require('fs');
 var parseArgs = require('minimist');
 var path = require('path');
 var _ = require('lodash');
-var grpc = require('../../../');
+var grpc = require('grpc');
 var routeguide = grpc.load(__dirname + '/route_guide.proto').routeguide;
 
 var COORD_FACTOR = 1e7;
diff --git a/examples/objective-c/helloworld/main.m b/examples/objective-c/helloworld/main.m
index a62f8362a2..bf357990a5 100644
--- a/examples/objective-c/helloworld/main.m
+++ b/examples/objective-c/helloworld/main.m
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -34,6 +34,7 @@
 #import <UIKit/UIKit.h>
 #import "AppDelegate.h"
 
+#import <GRPCClient/GRPCCall+ChannelArg.h>
 #import <GRPCClient/GRPCCall+Tests.h>
 #import <HelloWorld/Helloworld.pbrpc.h>
 
@@ -42,6 +43,7 @@ static NSString * const kHostAddress = @"localhost:50051";
 int main(int argc, char * argv[]) {
   @autoreleasepool {
     [GRPCCall useInsecureConnectionsForHost:kHostAddress];
+    [GRPCCall setUserAgentPrefix:@"HelloWorld/1.0" forHost:kHostAddress];
 
     HLWGreeter *client = [[HLWGreeter alloc] initWithHost:kHostAddress];
 
diff --git a/grpc.gemspec b/grpc.gemspec
index 6529c5cec7..07f7f03604 100755
--- a/grpc.gemspec
+++ b/grpc.gemspec
@@ -14,7 +14,6 @@ Gem::Specification.new do |s|
   s.license       = 'BSD-3-Clause'
 
   s.required_ruby_version = '>= 2.0.0'
-  s.requirements << 'libgrpc ~> 0.11.0 needs to be installed'
 
   s.files = %w( Makefile )
   s.files += %w( etc/roots.pem )
diff --git a/include/grpc/impl/codegen/sync.h b/include/grpc/impl/codegen/sync.h
index 7086b5d371..04ff0dc5bf 100644
--- a/include/grpc/impl/codegen/sync.h
+++ b/include/grpc/impl/codegen/sync.h
@@ -115,7 +115,8 @@ GPR_API void gpr_cv_destroy(gpr_cv *cv);
 /* Atomically release *mu and wait on *cv.  When the calling thread is woken
    from *cv or the deadline abs_deadline is exceeded, execute gpr_mu_lock(mu)
    and return whether the deadline was exceeded.  Use
-   abs_deadline==gpr_inf_future for no deadline.  May return even when not
+   abs_deadline==gpr_inf_future for no deadline.  abs_deadline can be either
+   an absolute deadline, or a GPR_TIMESPAN.  May return even when not
    woken explicitly.  Requires:  *mu and *cv initialized; the calling thread
    holds an exclusive lock on *mu.  */
 GPR_API int gpr_cv_wait(gpr_cv *cv, gpr_mu *mu, gpr_timespec abs_deadline);
diff --git a/include/grpc/impl/codegen/time.h b/include/grpc/impl/codegen/time.h
index b40c2b260c..4ed1c3cbd8 100644
--- a/include/grpc/impl/codegen/time.h
+++ b/include/grpc/impl/codegen/time.h
@@ -102,14 +102,16 @@ GPR_API gpr_timespec gpr_time_min(gpr_timespec a, gpr_timespec b);
 GPR_API gpr_timespec gpr_time_add(gpr_timespec a, gpr_timespec b);
 GPR_API gpr_timespec gpr_time_sub(gpr_timespec a, gpr_timespec b);
 
-/* Return a timespec representing a given number of time units. LONG_MIN is
-   interpreted as gpr_inf_past, and LONG_MAX as gpr_inf_future.  */
-GPR_API gpr_timespec gpr_time_from_micros(long x, gpr_clock_type clock_type);
-GPR_API gpr_timespec gpr_time_from_nanos(long x, gpr_clock_type clock_type);
-GPR_API gpr_timespec gpr_time_from_millis(long x, gpr_clock_type clock_type);
-GPR_API gpr_timespec gpr_time_from_seconds(long x, gpr_clock_type clock_type);
-GPR_API gpr_timespec gpr_time_from_minutes(long x, gpr_clock_type clock_type);
-GPR_API gpr_timespec gpr_time_from_hours(long x, gpr_clock_type clock_type);
+/* Return a timespec representing a given number of time units. INT64_MIN is
+   interpreted as gpr_inf_past, and INT64_MAX as gpr_inf_future.  */
+GPR_API gpr_timespec gpr_time_from_micros(int64_t x, gpr_clock_type clock_type);
+GPR_API gpr_timespec gpr_time_from_nanos(int64_t x, gpr_clock_type clock_type);
+GPR_API gpr_timespec gpr_time_from_millis(int64_t x, gpr_clock_type clock_type);
+GPR_API gpr_timespec
+gpr_time_from_seconds(int64_t x, gpr_clock_type clock_type);
+GPR_API gpr_timespec
+gpr_time_from_minutes(int64_t x, gpr_clock_type clock_type);
+GPR_API gpr_timespec gpr_time_from_hours(int64_t x, gpr_clock_type clock_type);
 
 GPR_API int32_t gpr_time_to_millis(gpr_timespec timespec);
 
diff --git a/setup.py b/setup.py
index 720e4f75f6..3e8a7abe34 100644
--- a/setup.py
+++ b/setup.py
@@ -118,6 +118,8 @@ def cython_extensions(package_names, module_names, extra_sources, include_dirs,
           sources=[module_file] + extra_sources,
           include_dirs=include_dirs, libraries=libraries,
           define_macros=define_macros,
+          extra_compile_args=list(CFLAGS),
+          extra_link_args=list(LDFLAGS),
       ) for (module_name, module_file) in zip(module_names, module_files)
   ]
   if build_with_cython:
@@ -216,7 +218,7 @@ else:
 
 setuptools.setup(
     name='grpcio',
-    version='0.12.0b8',
+    version='0.12.0b9',
     license=LICENSE,
     ext_modules=CYTHON_EXTENSION_MODULES,
     packages=list(PACKAGES),
diff --git a/src/core/iomgr/iocp_windows.c b/src/core/iomgr/iocp_windows.c
index 96b6f81024..759340e00e 100644
--- a/src/core/iomgr/iocp_windows.c
+++ b/src/core/iomgr/iocp_windows.c
@@ -57,7 +57,7 @@ static HANDLE g_iocp;
 static DWORD deadline_to_millis_timeout(gpr_timespec deadline,
                                         gpr_timespec now) {
   gpr_timespec timeout;
-  static const int max_spin_polling_us = 10;
+  static const int64_t max_spin_polling_us = 10;
   if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) == 0) {
     return INFINITE;
   }
diff --git a/src/core/iomgr/pollset_posix.c b/src/core/iomgr/pollset_posix.c
index a8e2e22977..19ee6650f0 100644
--- a/src/core/iomgr/pollset_posix.c
+++ b/src/core/iomgr/pollset_posix.c
@@ -393,7 +393,7 @@ void grpc_pollset_shutdown(grpc_exec_ctx *exec_ctx, grpc_pollset *pollset,
 int grpc_poll_deadline_to_millis_timeout(gpr_timespec deadline,
                                          gpr_timespec now) {
   gpr_timespec timeout;
-  static const int max_spin_polling_us = 10;
+  static const int64_t max_spin_polling_us = 10;
   if (gpr_time_cmp(deadline, gpr_inf_future(deadline.clock_type)) == 0) {
     return -1;
   }
diff --git a/src/core/iomgr/tcp_server.h b/src/core/iomgr/tcp_server.h
index 8f3184ff1e..a39dd3bafc 100644
--- a/src/core/iomgr/tcp_server.h
+++ b/src/core/iomgr/tcp_server.h
@@ -40,15 +40,14 @@
 /* Forward decl of grpc_tcp_server */
 typedef struct grpc_tcp_server grpc_tcp_server;
 
-typedef struct grpc_tcp_server_acceptor grpc_tcp_server_acceptor;
-struct grpc_tcp_server_acceptor {
+typedef struct grpc_tcp_server_acceptor {
   /* grpc_tcp_server_cb functions share a ref on from_server that is valid
      until the function returns. */
   grpc_tcp_server *from_server;
   /* Indices that may be passed to grpc_tcp_server_port_fd(). */
   unsigned port_index;
   unsigned fd_index;
-};
+} grpc_tcp_server_acceptor;
 
 /* Called for newly connected TCP connections. */
 typedef void (*grpc_tcp_server_cb)(grpc_exec_ctx *exec_ctx, void *arg,
@@ -57,7 +56,7 @@ typedef void (*grpc_tcp_server_cb)(grpc_exec_ctx *exec_ctx, void *arg,
 
 /* Create a server, initially not bound to any ports. The caller owns one ref.
    If shutdown_complete is not NULL, it will be used by
-   grpc_tcp_server_unref(). */
+   grpc_tcp_server_unref() when the ref count reaches zero. */
 grpc_tcp_server *grpc_tcp_server_create(grpc_closure *shutdown_complete);
 
 /* Start listening to bound ports */
@@ -84,7 +83,7 @@ unsigned grpc_tcp_server_port_fd_count(grpc_tcp_server *s, unsigned port_index);
 /* Returns the file descriptor of the Mth (fd_index) listening socket of the Nth
    (port_index) call to add_port() on this server, or -1 if the indices are out
    of bounds. The file descriptor remains owned by the server, and will be
-   cleaned up when grpc_tcp_server_destroy is called. */
+   cleaned up when the ref count reaches zero. */
 int grpc_tcp_server_port_fd(grpc_tcp_server *s, unsigned port_index,
                             unsigned fd_index);
 
@@ -97,7 +96,7 @@ grpc_tcp_server *grpc_tcp_server_ref(grpc_tcp_server *s);
 void grpc_tcp_server_shutdown_starting_add(grpc_tcp_server *s,
                                            grpc_closure *shutdown_starting);
 
-/* If the recount drops to zero, delete s, and call (exec_ctx==NULL) or enqueue
+/* If the refcount drops to zero, delete s, and call (exec_ctx==NULL) or enqueue
    a call (exec_ctx!=NULL) to shutdown_complete. */
 void grpc_tcp_server_unref(grpc_exec_ctx *exec_ctx, grpc_tcp_server *s);
 
diff --git a/src/core/support/stack_lockfree.c b/src/core/support/stack_lockfree.c
index 2c97ee18be..9daecd2e18 100644
--- a/src/core/support/stack_lockfree.c
+++ b/src/core/support/stack_lockfree.c
@@ -99,7 +99,7 @@ gpr_stack_lockfree *gpr_stack_lockfree_create(size_t entries) {
 
   /* Point the head at reserved dummy entry */
   stack->head.contents.index = INVALID_ENTRY_INDEX;
-  /* Fill in the pad and aba_ctr to avoid confusing memcheck tools */
+/* Fill in the pad and aba_ctr to avoid confusing memcheck tools */
 #ifdef GPR_ARCH_64
   stack->head.contents.pad = 0;
 #endif
diff --git a/src/core/support/sync_win32.c b/src/core/support/sync_win32.c
index 84d412a75f..41998ebcb6 100644
--- a/src/core/support/sync_win32.c
+++ b/src/core/support/sync_win32.c
@@ -87,6 +87,7 @@ int gpr_cv_wait(gpr_cv *cv, gpr_mu *mu, gpr_timespec abs_deadline) {
       0) {
     SleepConditionVariableCS(cv, &mu->cs, INFINITE);
   } else {
+    abs_deadline = gpr_convert_clock_type(abs_deadline, GPR_CLOCK_REALTIME);
     gpr_timespec now = gpr_now(abs_deadline.clock_type);
     int64_t now_ms = (int64_t)now.tv_sec * 1000 + now.tv_nsec / 1000000;
     int64_t deadline_ms =
diff --git a/src/core/support/time.c b/src/core/support/time.c
index ac8c3bcde5..423d12ffc0 100644
--- a/src/core/support/time.c
+++ b/src/core/support/time.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -83,12 +83,12 @@ gpr_timespec gpr_inf_past(gpr_clock_type type) {
 /* TODO(ctiller): consider merging _nanos, _micros, _millis into a single
    function for maintainability. Similarly for _seconds, _minutes, and _hours */
 
-gpr_timespec gpr_time_from_nanos(long ns, gpr_clock_type type) {
+gpr_timespec gpr_time_from_nanos(int64_t ns, gpr_clock_type type) {
   gpr_timespec result;
   result.clock_type = type;
-  if (ns == LONG_MAX) {
+  if (ns == INT64_MAX) {
     result = gpr_inf_future(type);
-  } else if (ns == LONG_MIN) {
+  } else if (ns == INT64_MIN) {
     result = gpr_inf_past(type);
   } else if (ns >= 0) {
     result.tv_sec = ns / GPR_NS_PER_SEC;
@@ -101,12 +101,12 @@ gpr_timespec gpr_time_from_nanos(long ns, gpr_clock_type type) {
   return result;
 }
 
-gpr_timespec gpr_time_from_micros(long us, gpr_clock_type type) {
+gpr_timespec gpr_time_from_micros(int64_t us, gpr_clock_type type) {
   gpr_timespec result;
   result.clock_type = type;
-  if (us == LONG_MAX) {
+  if (us == INT64_MAX) {
     result = gpr_inf_future(type);
-  } else if (us == LONG_MIN) {
+  } else if (us == INT64_MIN) {
     result = gpr_inf_past(type);
   } else if (us >= 0) {
     result.tv_sec = us / 1000000;
@@ -119,12 +119,12 @@ gpr_timespec gpr_time_from_micros(long us, gpr_clock_type type) {
   return result;
 }
 
-gpr_timespec gpr_time_from_millis(long ms, gpr_clock_type type) {
+gpr_timespec gpr_time_from_millis(int64_t ms, gpr_clock_type type) {
   gpr_timespec result;
   result.clock_type = type;
-  if (ms == LONG_MAX) {
+  if (ms == INT64_MAX) {
     result = gpr_inf_future(type);
-  } else if (ms == LONG_MIN) {
+  } else if (ms == INT64_MIN) {
     result = gpr_inf_past(type);
   } else if (ms >= 0) {
     result.tv_sec = ms / 1000;
@@ -137,12 +137,12 @@ gpr_timespec gpr_time_from_millis(long ms, gpr_clock_type type) {
   return result;
 }
 
-gpr_timespec gpr_time_from_seconds(long s, gpr_clock_type type) {
+gpr_timespec gpr_time_from_seconds(int64_t s, gpr_clock_type type) {
   gpr_timespec result;
   result.clock_type = type;
-  if (s == LONG_MAX) {
+  if (s == INT64_MAX) {
     result = gpr_inf_future(type);
-  } else if (s == LONG_MIN) {
+  } else if (s == INT64_MIN) {
     result = gpr_inf_past(type);
   } else {
     result.tv_sec = s;
@@ -151,12 +151,12 @@ gpr_timespec gpr_time_from_seconds(long s, gpr_clock_type type) {
   return result;
 }
 
-gpr_timespec gpr_time_from_minutes(long m, gpr_clock_type type) {
+gpr_timespec gpr_time_from_minutes(int64_t m, gpr_clock_type type) {
   gpr_timespec result;
   result.clock_type = type;
-  if (m >= LONG_MAX / 60) {
+  if (m >= INT64_MAX / 60) {
     result = gpr_inf_future(type);
-  } else if (m <= LONG_MIN / 60) {
+  } else if (m <= INT64_MIN / 60) {
     result = gpr_inf_past(type);
   } else {
     result.tv_sec = m * 60;
@@ -165,12 +165,12 @@ gpr_timespec gpr_time_from_minutes(long m, gpr_clock_type type) {
   return result;
 }
 
-gpr_timespec gpr_time_from_hours(long h, gpr_clock_type type) {
+gpr_timespec gpr_time_from_hours(int64_t h, gpr_clock_type type) {
   gpr_timespec result;
   result.clock_type = type;
-  if (h >= LONG_MAX / 3600) {
+  if (h >= INT64_MAX / 3600) {
     result = gpr_inf_future(type);
-  } else if (h <= LONG_MIN / 3600) {
+  } else if (h <= INT64_MIN / 3600) {
     result = gpr_inf_past(type);
   } else {
     result.tv_sec = h * 3600;
diff --git a/src/core/transport/chttp2/writing.c b/src/core/transport/chttp2/writing.c
index 095883c66d..cafecf1046 100644
--- a/src/core/transport/chttp2/writing.c
+++ b/src/core/transport/chttp2/writing.c
@@ -75,6 +75,9 @@ int grpc_chttp2_unlocking_check_writes(
 
   GRPC_CHTTP2_FLOW_MOVE_TRANSPORT("write", transport_writing, outgoing_window,
                                   transport_global, outgoing_window);
+  bool is_window_available = transport_writing->outgoing_window > 0;
+  grpc_chttp2_list_flush_writing_stalled_by_transport(transport_writing,
+                                                      is_window_available);
 
   /* for each grpc_chttp2_stream that's become writable, frame it's data
      (according to available window sizes) and add to the output buffer */
@@ -329,10 +332,6 @@ void grpc_chttp2_cleanup_writing(
     grpc_chttp2_transport_writing *transport_writing) {
   grpc_chttp2_stream_writing *stream_writing;
   grpc_chttp2_stream_global *stream_global;
-  bool is_window_available = transport_writing->outgoing_window > 0;
-
-  grpc_chttp2_list_flush_writing_stalled_by_transport(transport_writing,
-                                                      is_window_available);
 
   while (grpc_chttp2_list_pop_written_stream(
       transport_global, transport_writing, &stream_global, &stream_writing)) {
diff --git a/src/node/ext/timeval.cc b/src/node/ext/timeval.cc
index 64015e8412..c8f8534cfa 100644
--- a/src/node/ext/timeval.cc
+++ b/src/node/ext/timeval.cc
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -32,6 +32,7 @@
  */
 
 #include <limits>
+#include <cstdint>
 
 #include "grpc/grpc.h"
 #include "grpc/support/time.h"
@@ -46,7 +47,7 @@ gpr_timespec MillisecondsToTimespec(double millis) {
   } else if (millis == -std::numeric_limits<double>::infinity()) {
     return gpr_inf_past(GPR_CLOCK_REALTIME);
   } else {
-    return gpr_time_from_micros(static_cast<long>(millis * 1000),
+    return gpr_time_from_micros(static_cast<int64_t>(millis * 1000),
                                 GPR_CLOCK_REALTIME);
   }
 }
diff --git a/src/objective-c/GRPCClient/private/GRPCUnsecuredChannel.h b/src/objective-c/GRPCClient/GRPCCall+ChannelArg.h
index 8528be44c0..bd6b064f16 100644
--- a/src/objective-c/GRPCClient/private/GRPCUnsecuredChannel.h
+++ b/src/objective-c/GRPCClient/GRPCCall+ChannelArg.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -30,9 +30,17 @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  *
  */
+#import "GRPCCall.h"
 
-#import "GRPCChannel.h"
+/**
+ * Methods to configure GRPC channel options.
+ */
+@interface GRPCCall (ChannelArg)
+
+/**
+ * Use the provided @c userAgentPrefix at the beginning of the HTTP User Agent string for all calls
+ * to the specified @c host.
+ */
++ (void)setUserAgentPrefix:(NSString *)userAgentPrefix forHost:(NSString *)host;
 
-@interface GRPCUnsecuredChannel : GRPCChannel
-- (instancetype)initWithHost:(NSString *)host NS_DESIGNATED_INITIALIZER;
 @end
diff --git a/src/objective-c/GRPCClient/private/GRPCUnsecuredChannel.m b/src/objective-c/GRPCClient/GRPCCall+ChannelArg.m
index 15b6ffc75c..5f9932d86d 100644
--- a/src/objective-c/GRPCClient/private/GRPCUnsecuredChannel.m
+++ b/src/objective-c/GRPCClient/GRPCCall+ChannelArg.m
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -31,20 +31,19 @@
  *
  */
 
-#import "GRPCUnsecuredChannel.h"
+#import "GRPCCall+ChannelArg.h"
 
-#include <grpc/grpc.h>
+#import "private/GRPCHost.h"
 
-@implementation GRPCUnsecuredChannel
+@implementation GRPCCall (ChannelArg)
 
-- (instancetype)initWithHost:(NSString *)host {
-  return (self = [super initWithChannel:grpc_insecure_channel_create(host.UTF8String, NULL, NULL)]);
++ (void)setUserAgentPrefix:(NSString *)userAgentPrefix forHost:(NSString *)host {
+  if (!host) {
+    [NSException raise:NSInvalidArgumentException
+                format:@"host and userAgentPrefix must be provided."];
+  }
+  GRPCHost *hostConfig = [GRPCHost hostWithAddress:host];
+  hostConfig.userAgentPrefix = userAgentPrefix;
 }
 
-// TODO(jcanizales): GRPCSecureChannel and GRPCUnsecuredChannel are just convenience initializers
-// for GRPCChannel. Move them into GRPCChannel, which will make the following unnecessary.
-- (instancetype)initWithChannel:(grpc_channel *)unmanagedChannel {
-  [NSException raise:NSInternalInconsistencyException format:@"use the other initializer"];
-  return [self initWithHost:nil]; // silence warnings
-}
 @end
diff --git a/src/objective-c/GRPCClient/private/GRPCChannel.h b/src/objective-c/GRPCClient/private/GRPCChannel.h
index e2d19d506a..8661ae6f97 100644
--- a/src/objective-c/GRPCClient/private/GRPCChannel.h
+++ b/src/objective-c/GRPCClient/private/GRPCChannel.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -33,18 +33,51 @@
 
 #import <Foundation/Foundation.h>
 
-struct grpc_channel;
+#include <grpc/grpc.h>
+
+struct grpc_channel_credentials;
+
 
 /**
  * Each separate instance of this class represents at least one TCP connection to the provided host.
- * Create them using one of the subclasses |GRPCSecureChannel| and |GRPCUnsecuredChannel|.
  */
 @interface GRPCChannel : NSObject
-@property(nonatomic, readonly) struct grpc_channel *unmanagedChannel;
+
+@property(nonatomic, readonly, nonnull) struct grpc_channel *unmanagedChannel;
+
+- (nullable instancetype)init NS_UNAVAILABLE;
 
 /**
- * This initializer takes ownership of the passed channel, and will destroy it when this object is
- * deallocated. It's illegal to pass the same grpc_channel to two different GRPCChannel objects.
+ * Creates a secure channel to the specified @c host using default credentials and channel
+ * arguments. If certificates could not be found to create a secure channel, then @c nil is
+ * returned.
  */
-- (instancetype)initWithChannel:(struct grpc_channel *)unmanagedChannel NS_DESIGNATED_INITIALIZER;
++ (nullable GRPCChannel *)secureChannelWithHost:(nonnull NSString *)host;
+
+/**
+ * Creates a secure channel to the specified @c host using the specified @c pathToCertificates and 
+ * @c channelArgs. Only in tests should @c pathToCertificates be nil or
+ * @c GRPC_SSL_TARGET_NAME_OVERRIDE_ARG channel arg be set. Passing nil for @c pathToCertificates
+ * results in using the default root certificates distributed with the library. If certificates
+ * could not be found in any case, then @c nil is returned.
+ */
++ (nullable GRPCChannel *)secureChannelWithHost:(nonnull NSString *)host
+                             pathToCertificates:(nullable NSString *)pathToCertificates
+                                    channelArgs:(nullable NSDictionary *)channelArgs;
+
+
+/**
+ * Creates a secure channel to the specified @c host using the specified @c credentials and
+ * @c channelArgs. Only in tests should @c GRPC_SSL_TARGET_NAME_OVERRIDE_ARG channel arg be set.
+ */
++ (nonnull GRPCChannel *)secureChannelWithHost:(nonnull NSString *)host
+    credentials:(nonnull struct grpc_channel_credentials *)credentials
+    channelArgs:(nullable NSDictionary *)channelArgs;
+
+/**
+ * Creates an insecure channel to the specified @c host using the specified @c channelArgs.
+ */
++ (nonnull GRPCChannel *)insecureChannelWithHost:(nonnull NSString *)host
+                                     channelArgs:(nullable NSDictionary *)channelArgs;
+
 @end
diff --git a/src/objective-c/GRPCClient/private/GRPCChannel.m b/src/objective-c/GRPCClient/private/GRPCChannel.m
index 4366e63320..7e55a473d7 100644
--- a/src/objective-c/GRPCClient/private/GRPCChannel.m
+++ b/src/objective-c/GRPCClient/private/GRPCChannel.m
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -33,22 +33,114 @@
 
 #import "GRPCChannel.h"
 
-#include <grpc/grpc.h>
+#include <grpc/grpc_security.h>
+#include <grpc/support/alloc.h>
+#include <grpc/support/log.h>
+#include <grpc/support/string_util.h>
 
-@implementation GRPCChannel
+/**
+ * Returns @c grpc_channel_credentials from the specified @c path. If the file at the path could not
+ * be read then NULL is returned. If NULL is returned, @c errorPtr may not be NULL if there are
+ * details available describing what went wrong.
+ */
+static grpc_channel_credentials *CertificatesAtPath(NSString *path, NSError **errorPtr) {
+  // Files in PEM format can have non-ASCII characters in their comments (e.g. for the name of the
+  // issuer). Load them as UTF8 and produce an ASCII equivalent.
+  NSString *contentInUTF8 = [NSString stringWithContentsOfFile:path
+                                                      encoding:NSUTF8StringEncoding
+                                                         error:errorPtr];
+  NSData *contentInASCII = [contentInUTF8 dataUsingEncoding:NSASCIIStringEncoding
+                                       allowLossyConversion:YES];
+  if (!contentInASCII.bytes) {
+    // Passing NULL to grpc_ssl_credentials_create produces behavior we don't want, so return.
+    return NULL;
+  }
+  return grpc_ssl_credentials_create(contentInASCII.bytes, NULL, NULL);
+}
+
+void freeChannelArgs(grpc_channel_args *channel_args) {
+  for (size_t i = 0; i < channel_args->num_args; ++i) {
+    grpc_arg *arg = &channel_args->args[i];
+    gpr_free(arg->key);
+    if (arg->type == GRPC_ARG_STRING) {
+      gpr_free(arg->value.string);
+    }
+  }
+  gpr_free(channel_args);
+}
+
+/**
+ * Allocates a @c grpc_channel_args and populates it with the options specified in the
+ * @c dictionary. Keys must be @c NSString. If the value responds to @c @selector(UTF8String) then
+ * it will be mapped to @c GRPC_ARG_STRING. If not, it will be mapped to @c GRPC_ARG_INTEGER if the
+ * value responds to @c @selector(intValue). Otherwise, an exception will be raised. The caller of
+ * this function is responsible for calling @c freeChannelArgs on a non-NULL returned value.
+ */
+grpc_channel_args * buildChannelArgs(NSDictionary *dictionary) {
+  if (!dictionary) {
+    return NULL;
+  }
 
-- (instancetype)init {
-  return [self initWithChannel:NULL];
+  NSArray *keys = [dictionary allKeys];
+  NSUInteger argCount = [keys count];
+
+  grpc_channel_args *channelArgs = gpr_malloc(sizeof(grpc_channel_args));
+  channelArgs->num_args = argCount;
+  channelArgs->args = gpr_malloc(argCount * sizeof(grpc_arg));
+
+  // TODO(kriswuollett) Check that keys adhere to GRPC core library requirements
+
+  for (NSUInteger i = 0; i < argCount; ++i) {
+    grpc_arg *arg = &channelArgs->args[i];
+    arg->key = gpr_strdup([keys[i] UTF8String]);
+
+    id value = dictionary[keys[i]];
+    if ([value respondsToSelector:@selector(UTF8String)]) {
+      arg->type = GRPC_ARG_STRING;
+      arg->value.string = gpr_strdup([value UTF8String]);
+    } else if ([value respondsToSelector:@selector(intValue)]) {
+      arg->type = GRPC_ARG_INTEGER;
+      arg->value.integer = [value intValue];
+    } else {
+      [NSException raise:NSInvalidArgumentException
+                  format:@"Invalid value type: %@", [value class]];
+    }
+  }
+
+  return channelArgs;
+}
+
+@implementation GRPCChannel {
+  // Retain arguments to channel_create because they may not be used on the thread that invoked
+  // the channel_create function.
+  NSString *_host;
+  grpc_channel_args *_channelArgs;
 }
 
-// Designated initializer
-- (instancetype)initWithChannel:(grpc_channel *)unmanagedChannel {
-  if (!unmanagedChannel) {
+
+- (instancetype)initWithHost:(NSString *)host
+                      secure:(BOOL)secure
+                 credentials:(struct grpc_channel_credentials *)credentials
+                 channelArgs:(NSDictionary *)channelArgs {
+  if (!host) {
+    [NSException raise:NSInvalidArgumentException format:@"host argument missing"];
+  }
+
+  if (secure && !credentials) {
     return nil;
   }
-  if ((self = [super init])) {
-    _unmanagedChannel = unmanagedChannel;
+
+  if (self = [super init]) {
+    _channelArgs = buildChannelArgs(channelArgs);
+    _host = [host copy];
+    if (secure) {
+      _unmanagedChannel = grpc_secure_channel_create(credentials, _host.UTF8String, _channelArgs,
+                                                     NULL);
+    } else {
+      _unmanagedChannel = grpc_insecure_channel_create(_host.UTF8String, _channelArgs, NULL);
+    }
   }
+
   return self;
 }
 
@@ -56,5 +148,61 @@
   // TODO(jcanizales): Be sure to add a test with a server that closes the connection prematurely,
   // as in the past that made this call to crash.
   grpc_channel_destroy(_unmanagedChannel);
+  freeChannelArgs(_channelArgs);
 }
+
++ (GRPCChannel *)secureChannelWithHost:(NSString *)host {
+  return [[GRPCChannel alloc] initWithHost:host secure:YES credentials:NULL channelArgs:NULL];
+}
+
++ (GRPCChannel *)secureChannelWithHost:(NSString *)host
+                    pathToCertificates:(NSString *)path
+                           channelArgs:(NSDictionary *)channelArgs {
+  // Load default SSL certificates once.
+  static grpc_channel_credentials *kDefaultCertificates;
+  static dispatch_once_t loading;
+  dispatch_once(&loading, ^{
+    NSString *defaultPath = @"gRPCCertificates.bundle/roots"; // .pem
+    // Do not use NSBundle.mainBundle, as it's nil for tests of library projects.
+    NSBundle *bundle = [NSBundle bundleForClass:self.class];
+    NSString *path = [bundle pathForResource:defaultPath ofType:@"pem"];
+    NSError *error;
+    kDefaultCertificates = CertificatesAtPath(path, &error);
+    NSAssert(kDefaultCertificates, @"Could not read %@/%@.pem. This file, with the root "
+             "certificates, is needed to establish secure (TLS) connections. Because the file is "
+             "distributed with the gRPC library, this error is usually a sign that the library "
+             "wasn't configured correctly for your project. Error: %@",
+             bundle.bundlePath, defaultPath, error);
+  });
+
+  //TODO(jcanizales): Add NSError** parameter to the initializer.
+  grpc_channel_credentials *certificates = path
+      ? CertificatesAtPath(path, NULL)
+      : kDefaultCertificates;
+
+  return [[GRPCChannel alloc] initWithHost:host
+                                    secure:YES
+                               credentials:certificates
+                               channelArgs:channelArgs];
+}
+
+
++ (GRPCChannel *)secureChannelWithHost:(NSString *)host
+                           credentials:(struct grpc_channel_credentials *)credentials
+                           channelArgs:(NSDictionary *)channelArgs {
+  return [[GRPCChannel alloc] initWithHost:host
+                                    secure:YES
+                               credentials:credentials
+                               channelArgs:channelArgs];
+
+}
+
++ (GRPCChannel *)insecureChannelWithHost:(NSString *)host
+                             channelArgs:(NSDictionary *)channelArgs {
+  return [[GRPCChannel alloc] initWithHost:host
+                                    secure:NO
+                               credentials:NULL
+                               channelArgs:channelArgs];
+}
+
 @end
diff --git a/src/objective-c/GRPCClient/private/GRPCHost.h b/src/objective-c/GRPCClient/private/GRPCHost.h
index 6b4f98746d..82c0ad6cf6 100644
--- a/src/objective-c/GRPCClient/private/GRPCHost.h
+++ b/src/objective-c/GRPCClient/private/GRPCHost.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -39,6 +39,7 @@ struct grpc_call;
 @interface GRPCHost : NSObject
 
 @property(nonatomic, readonly) NSString *address;
+@property(nonatomic, copy) NSString *userAgentPrefix;
 
 /** The following properties should only be modified for testing: */
 
diff --git a/src/objective-c/GRPCClient/private/GRPCHost.m b/src/objective-c/GRPCClient/private/GRPCHost.m
index a8cd3a0e74..eb1db899b7 100644
--- a/src/objective-c/GRPCClient/private/GRPCHost.m
+++ b/src/objective-c/GRPCClient/private/GRPCHost.m
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -34,11 +34,15 @@
 #import "GRPCHost.h"
 
 #include <grpc/grpc.h>
+#import <GRPCClient/GRPCCall+ChannelArg.h>
 
 #import "GRPCChannel.h"
 #import "GRPCCompletionQueue.h"
-#import "GRPCSecureChannel.h"
-#import "GRPCUnsecuredChannel.h"
+#import "NSDictionary+GRPC.h"
+
+// TODO(jcanizales): Generate the version in a standalone header, from templates. Like
+// templates/src/core/surface/version.c.template .
+#define GRPC_OBJC_VERSION_STRING @"0.13.0"
 
 @interface GRPCHost ()
 // TODO(mlumish): Investigate whether caching channels with strong links is a good idea.
@@ -106,13 +110,28 @@
 - (GRPCChannel *)channel {
   // Create it lazily, because we don't want to open a connection just because someone is
   // configuring a host.
+
   if (!_channel) {
+    NSMutableDictionary *args = [NSMutableDictionary dictionary];
+
+    // TODO(jcanizales): Add OS and device information (see
+    // https://github.com/grpc/grpc/blob/master/doc/PROTOCOL-HTTP2.md#user-agents ).
+    NSString *userAgent = @"grpc-objc/" GRPC_OBJC_VERSION_STRING;
+    if (_userAgentPrefix) {
+      userAgent = [@[_userAgentPrefix, userAgent] componentsJoinedByString:@" "];
+    }
+    args[@GRPC_ARG_PRIMARY_USER_AGENT_STRING] = userAgent;
+
     if (_secure) {
-      _channel = [[GRPCSecureChannel alloc] initWithHost:_address
-                                      pathToCertificates:_pathToCertificates
-                                        hostNameOverride:_hostNameOverride];
+      if (_hostNameOverride) {
+        args[@GRPC_SSL_TARGET_NAME_OVERRIDE_ARG] = _hostNameOverride;
+      }
+
+      _channel = [GRPCChannel secureChannelWithHost:_address
+                                 pathToCertificates:_pathToCertificates
+                                        channelArgs:args];
     } else {
-      _channel = [[GRPCUnsecuredChannel alloc] initWithHost:_address];
+      _channel = [GRPCChannel insecureChannelWithHost:_address channelArgs:args];
     }
   }
   return _channel;
diff --git a/src/objective-c/GRPCClient/private/GRPCSecureChannel.h b/src/objective-c/GRPCClient/private/GRPCSecureChannel.h
deleted file mode 100644
index b82b9fe35a..0000000000
--- a/src/objective-c/GRPCClient/private/GRPCSecureChannel.h
+++ /dev/null
@@ -1,55 +0,0 @@
-/*
- *
- * 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.
- *
- */
-
-#include <grpc/grpc.h>
-
-#import "GRPCChannel.h"
-
-struct grpc_channel_credentials;
-
-@interface GRPCSecureChannel : GRPCChannel
-- (instancetype)initWithHost:(NSString *)host;
-
-/**
- * Only in tests shouldn't pathToCertificates or hostNameOverride be nil. Passing nil for
- * pathToCertificates results in using the default root certificates distributed with the library.
- */
-- (instancetype)initWithHost:(NSString *)host
-          pathToCertificates:(NSString *)path
-            hostNameOverride:(NSString *)hostNameOverride;
-
-/** The passed arguments aren't required to be valid beyond the invocation of this initializer. */
-- (instancetype)initWithHost:(NSString *)host
-                 credentials:(struct grpc_channel_credentials *)credentials
-                        args:(grpc_channel_args *)args NS_DESIGNATED_INITIALIZER;
-@end
diff --git a/src/objective-c/GRPCClient/private/GRPCSecureChannel.m b/src/objective-c/GRPCClient/private/GRPCSecureChannel.m
deleted file mode 100644
index a573c171e9..0000000000
--- a/src/objective-c/GRPCClient/private/GRPCSecureChannel.m
+++ /dev/null
@@ -1,118 +0,0 @@
-/*
- *
- * 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.
- *
- */
-
-#import "GRPCSecureChannel.h"
-
-#include <grpc/grpc_security.h>
-
-// Returns NULL if the file at path couldn't be read. In that case, if errorPtr isn't NULL,
-// *errorPtr will be an object describing what went wrong.
-static grpc_channel_credentials *CertificatesAtPath(NSString *path, NSError **errorPtr) {
-  // Files in PEM format can have non-ASCII characters in their comments (e.g. for the name of the
-  // issuer). Load them as UTF8 and produce an ASCII equivalent.
-  NSString *contentInUTF8 = [NSString stringWithContentsOfFile:path
-                                                     encoding:NSUTF8StringEncoding
-                                                        error:errorPtr];
-  NSData *contentInASCII = [contentInUTF8 dataUsingEncoding:NSASCIIStringEncoding
-                                       allowLossyConversion:YES];
-  if (!contentInASCII.bytes) {
-    // Passing NULL to grpc_ssl_credentials_create produces behavior we don't want, so return.
-    return NULL;
-  }
-  return grpc_ssl_credentials_create(contentInASCII.bytes, NULL, NULL);
-}
-
-@implementation GRPCSecureChannel
-
-- (instancetype)initWithHost:(NSString *)host {
-  return [self initWithHost:host pathToCertificates:nil hostNameOverride:nil];
-}
-
-- (instancetype)initWithHost:(NSString *)host
-          pathToCertificates:(NSString *)path
-            hostNameOverride:(NSString *)hostNameOverride {
-  // Load default SSL certificates once.
-  static grpc_channel_credentials *kDefaultCertificates;
-  static dispatch_once_t loading;
-  dispatch_once(&loading, ^{
-    NSString *defaultPath = @"gRPCCertificates.bundle/roots"; // .pem
-    // Do not use NSBundle.mainBundle, as it's nil for tests of library projects.
-    NSBundle *bundle = [NSBundle bundleForClass:self.class];
-    NSString *path = [bundle pathForResource:defaultPath ofType:@"pem"];
-    NSError *error;
-    kDefaultCertificates = CertificatesAtPath(path, &error);
-    NSAssert(kDefaultCertificates, @"Could not read %@/%@.pem. This file, with the root "
-             "certificates, is needed to establish secure (TLS) connections. Because the file is "
-             "distributed with the gRPC library, this error is usually a sign that the library "
-             "wasn't configured correctly for your project. Error: %@",
-             bundle.bundlePath, defaultPath, error);
-  });
-
-  //TODO(jcanizales): Add NSError** parameter to the initializer.
-  grpc_channel_credentials *certificates = path
-      ? CertificatesAtPath(path, NULL)
-      : kDefaultCertificates;
-  if (!certificates) {
-    return nil;
-  }
-
-  // Ritual to pass the SSL host name override to the C library.
-  grpc_channel_args channelArgs;
-  grpc_arg nameOverrideArg;
-  channelArgs.num_args = 1;
-  channelArgs.args = &nameOverrideArg;
-  nameOverrideArg.type = GRPC_ARG_STRING;
-  nameOverrideArg.key = GRPC_SSL_TARGET_NAME_OVERRIDE_ARG;
-  // Cast const away. Hope C gRPC doesn't modify it!
-  nameOverrideArg.value.string = (char *) hostNameOverride.UTF8String;
-  grpc_channel_args *args = hostNameOverride ? &channelArgs : NULL;
-
-  return [self initWithHost:host credentials:certificates args:args];
-}
-
-- (instancetype)initWithHost:(NSString *)host
-                 credentials:(grpc_channel_credentials *)credentials
-                        args:(grpc_channel_args *)args {
-  return (self = [super
-              initWithChannel:grpc_secure_channel_create(
-                                  credentials, host.UTF8String, args, NULL)]);
-}
-
-// TODO(jcanizales): GRPCSecureChannel and GRPCUnsecuredChannel are just convenience initializers
-// for GRPCChannel. Move them into GRPCChannel, which will make the following unnecessary.
-- (instancetype)initWithChannel:(grpc_channel *)unmanagedChannel {
-  [NSException raise:NSInternalInconsistencyException format:@"use another initializer"];
-  return [self initWithHost:nil]; // silence warnings
-}
-
-@end
diff --git a/src/python/grpcio/commands.py b/src/python/grpcio/commands.py
index 490d0f07b3..31bd00e94e 100644
--- a/src/python/grpcio/commands.py
+++ b/src/python/grpcio/commands.py
@@ -135,7 +135,7 @@ class Install(install.install, EggNameMixin):
 
   def initialize_options(self):
     install.install.initialize_options(self)
-    self.use_grpc_custom_bdist = False
+    self.use_grpc_custom_bdist = bool(int(os.environ.get('GRPC_PYTHON_USE_CUSTOM_BDIST', '1')))
 
   def finalize_options(self):
     install.install.finalize_options(self)
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxi b/src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxi
index 9d6e017026..9c85e0ee1b 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxi
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/grpc.pxi
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
diff --git a/src/python/grpcio/grpc/_cython/_cygrpc/records.pyx.pxi b/src/python/grpcio/grpc/_cython/_cygrpc/records.pyx.pxi
index 9e14b967e0..fa4ea99ea9 100644
--- a/src/python/grpcio/grpc/_cython/_cygrpc/records.pyx.pxi
+++ b/src/python/grpcio/grpc/_cython/_cygrpc/records.pyx.pxi
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
diff --git a/src/python/grpcio/grpc/_cython/cygrpc.pyx b/src/python/grpcio/grpc/_cython/cygrpc.pyx
index 579bac7b8a..b1836bf5be 100644
--- a/src/python/grpcio/grpc/_cython/cygrpc.pyx
+++ b/src/python/grpcio/grpc/_cython/cygrpc.pyx
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
diff --git a/src/python/grpcio/grpc/_cython/imports.generated.h b/src/python/grpcio/grpc/_cython/imports.generated.h
index f85d416db8..6d0a6e06c0 100644
--- a/src/python/grpcio/grpc/_cython/imports.generated.h
+++ b/src/python/grpcio/grpc/_cython/imports.generated.h
@@ -655,22 +655,22 @@ extern gpr_time_add_type gpr_time_add_import;
 typedef gpr_timespec(*gpr_time_sub_type)(gpr_timespec a, gpr_timespec b);
 extern gpr_time_sub_type gpr_time_sub_import;
 #define gpr_time_sub gpr_time_sub_import
-typedef gpr_timespec(*gpr_time_from_micros_type)(long x, gpr_clock_type clock_type);
+typedef gpr_timespec(*gpr_time_from_micros_type)(int64_t x, gpr_clock_type clock_type);
 extern gpr_time_from_micros_type gpr_time_from_micros_import;
 #define gpr_time_from_micros gpr_time_from_micros_import
-typedef gpr_timespec(*gpr_time_from_nanos_type)(long x, gpr_clock_type clock_type);
+typedef gpr_timespec(*gpr_time_from_nanos_type)(int64_t x, gpr_clock_type clock_type);
 extern gpr_time_from_nanos_type gpr_time_from_nanos_import;
 #define gpr_time_from_nanos gpr_time_from_nanos_import
-typedef gpr_timespec(*gpr_time_from_millis_type)(long x, gpr_clock_type clock_type);
+typedef gpr_timespec(*gpr_time_from_millis_type)(int64_t x, gpr_clock_type clock_type);
 extern gpr_time_from_millis_type gpr_time_from_millis_import;
 #define gpr_time_from_millis gpr_time_from_millis_import
-typedef gpr_timespec(*gpr_time_from_seconds_type)(long x, gpr_clock_type clock_type);
+typedef gpr_timespec(*gpr_time_from_seconds_type)(int64_t x, gpr_clock_type clock_type);
 extern gpr_time_from_seconds_type gpr_time_from_seconds_import;
 #define gpr_time_from_seconds gpr_time_from_seconds_import
-typedef gpr_timespec(*gpr_time_from_minutes_type)(long x, gpr_clock_type clock_type);
+typedef gpr_timespec(*gpr_time_from_minutes_type)(int64_t x, gpr_clock_type clock_type);
 extern gpr_time_from_minutes_type gpr_time_from_minutes_import;
 #define gpr_time_from_minutes gpr_time_from_minutes_import
-typedef gpr_timespec(*gpr_time_from_hours_type)(long x, gpr_clock_type clock_type);
+typedef gpr_timespec(*gpr_time_from_hours_type)(int64_t x, gpr_clock_type clock_type);
 extern gpr_time_from_hours_type gpr_time_from_hours_import;
 #define gpr_time_from_hours gpr_time_from_hours_import
 typedef int32_t(*gpr_time_to_millis_type)(gpr_timespec timespec);
diff --git a/src/ruby/ext/grpc/extconf.rb b/src/ruby/ext/grpc/extconf.rb
index 426a6e67a0..b7c6cb3d7e 100644
--- a/src/ruby/ext/grpc/extconf.rb
+++ b/src/ruby/ext/grpc/extconf.rb
@@ -66,6 +66,8 @@ else
   grpc_lib_dir = File.join(grpc_root, 'libs', grpc_config)
 end
 
+ENV['MACOSX_DEPLOYMENT_TARGET'] = '10.7'
+
 unless File.exist?(File.join(grpc_lib_dir, 'libgrpc.a')) or windows
   ENV['AR'] = RbConfig::CONFIG['AR'] + ' rcs'
   ENV['CC'] = RbConfig::CONFIG['CC']
@@ -75,6 +77,7 @@ unless File.exist?(File.join(grpc_lib_dir, 'libgrpc.a')) or windows
 
   ENV['EMBED_OPENSSL'] = 'true'
   ENV['EMBED_ZLIB'] = 'true'
+  ENV['ARCH_FLAGS'] = RbConfig::CONFIG['ARCH_FLAG']
   ENV['ARCH_FLAGS'] = '-arch i386 -arch x86_64' if RUBY_PLATFORM =~ /darwin/
 
   output_dir = File.expand_path(RbConfig::CONFIG['topdir'])
diff --git a/src/ruby/ext/grpc/rb_channel.c b/src/ruby/ext/grpc/rb_channel.c
index d1e48753f2..0e6badbdaf 100644
--- a/src/ruby/ext/grpc/rb_channel.c
+++ b/src/ruby/ext/grpc/rb_channel.c
@@ -229,7 +229,7 @@ static VALUE grpc_rb_channel_watch_connectivity_state(VALUE self,
   }
   grpc_channel_watch_connectivity_state(
       ch,
-      NUM2LONG(last_state),
+      (grpc_connectivity_state)NUM2LONG(last_state),
       grpc_rb_time_timeval(deadline, /* absolute time */ 0),
       cq,
       ROBJECT(tag));
diff --git a/src/ruby/ext/grpc/rb_grpc_imports.generated.h b/src/ruby/ext/grpc/rb_grpc_imports.generated.h
index 45e9b47574..618ae5e7fc 100644
--- a/src/ruby/ext/grpc/rb_grpc_imports.generated.h
+++ b/src/ruby/ext/grpc/rb_grpc_imports.generated.h
@@ -655,22 +655,22 @@ extern gpr_time_add_type gpr_time_add_import;
 typedef gpr_timespec(*gpr_time_sub_type)(gpr_timespec a, gpr_timespec b);
 extern gpr_time_sub_type gpr_time_sub_import;
 #define gpr_time_sub gpr_time_sub_import
-typedef gpr_timespec(*gpr_time_from_micros_type)(long x, gpr_clock_type clock_type);
+typedef gpr_timespec(*gpr_time_from_micros_type)(int64_t x, gpr_clock_type clock_type);
 extern gpr_time_from_micros_type gpr_time_from_micros_import;
 #define gpr_time_from_micros gpr_time_from_micros_import
-typedef gpr_timespec(*gpr_time_from_nanos_type)(long x, gpr_clock_type clock_type);
+typedef gpr_timespec(*gpr_time_from_nanos_type)(int64_t x, gpr_clock_type clock_type);
 extern gpr_time_from_nanos_type gpr_time_from_nanos_import;
 #define gpr_time_from_nanos gpr_time_from_nanos_import
-typedef gpr_timespec(*gpr_time_from_millis_type)(long x, gpr_clock_type clock_type);
+typedef gpr_timespec(*gpr_time_from_millis_type)(int64_t x, gpr_clock_type clock_type);
 extern gpr_time_from_millis_type gpr_time_from_millis_import;
 #define gpr_time_from_millis gpr_time_from_millis_import
-typedef gpr_timespec(*gpr_time_from_seconds_type)(long x, gpr_clock_type clock_type);
+typedef gpr_timespec(*gpr_time_from_seconds_type)(int64_t x, gpr_clock_type clock_type);
 extern gpr_time_from_seconds_type gpr_time_from_seconds_import;
 #define gpr_time_from_seconds gpr_time_from_seconds_import
-typedef gpr_timespec(*gpr_time_from_minutes_type)(long x, gpr_clock_type clock_type);
+typedef gpr_timespec(*gpr_time_from_minutes_type)(int64_t x, gpr_clock_type clock_type);
 extern gpr_time_from_minutes_type gpr_time_from_minutes_import;
 #define gpr_time_from_minutes gpr_time_from_minutes_import
-typedef gpr_timespec(*gpr_time_from_hours_type)(long x, gpr_clock_type clock_type);
+typedef gpr_timespec(*gpr_time_from_hours_type)(int64_t x, gpr_clock_type clock_type);
 extern gpr_time_from_hours_type gpr_time_from_hours_import;
 #define gpr_time_from_hours gpr_time_from_hours_import
 typedef int32_t(*gpr_time_to_millis_type)(gpr_timespec timespec);
diff --git a/src/ruby/ext/grpc/rb_server_credentials.c b/src/ruby/ext/grpc/rb_server_credentials.c
index f866aecd28..4ea59b6b27 100644
--- a/src/ruby/ext/grpc/rb_server_credentials.c
+++ b/src/ruby/ext/grpc/rb_server_credentials.c
@@ -177,7 +177,7 @@ static VALUE grpc_rb_server_credentials_init(VALUE self, VALUE pem_root_certs,
   VALUE key = Qnil;
   VALUE key_cert = Qnil;
   int auth_client = 0;
-  int num_key_certs = 0;
+  long num_key_certs = 0;
   int i;
 
   if (NIL_P(force_client_auth) ||
diff --git a/src/ruby/lib/grpc/version.rb b/src/ruby/lib/grpc/version.rb
index 956e0222df..89ff882916 100644
--- a/src/ruby/lib/grpc/version.rb
+++ b/src/ruby/lib/grpc/version.rb
@@ -29,5 +29,5 @@
 
 # GRPC contains the General RPC module.
 module GRPC
-  VERSION = '0.12.0'
+  VERSION = '0.13.0.0'
 end
diff --git a/templates/grpc.gemspec.template b/templates/grpc.gemspec.template
index 9d034ddba1..c4987a6725 100644
--- a/templates/grpc.gemspec.template
+++ b/templates/grpc.gemspec.template
@@ -16,7 +16,6 @@
     s.license       = 'BSD-3-Clause'
 
     s.required_ruby_version = '>= 2.0.0'
-    s.requirements << 'libgrpc ~> 0.11.0 needs to be installed'
 
     s.files = %w( Makefile )
     s.files += %w( etc/roots.pem )
diff --git a/templates/src/ruby/lib/grpc/version.rb.template b/templates/src/ruby/lib/grpc/version.rb.template
new file mode 100644
index 0000000000..4859d2f883
--- /dev/null
+++ b/templates/src/ruby/lib/grpc/version.rb.template
@@ -0,0 +1,35 @@
+%YAML 1.2
+--- |
+  # Copyright 2015-2016, 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.
+
+  # GRPC contains the General RPC module.
+  module GRPC
+    VERSION = '${settings.version.major}.${settings.version.minor}.${settings.version.micro}.${settings.version.build}'
+  end
diff --git a/test/core/statistics/census_log_tests.c b/test/core/statistics/census_log_tests.c
index aac20fd96a..77cc57d4d6 100644
--- a/test/core/statistics/census_log_tests.c
+++ b/test/core/statistics/census_log_tests.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -237,8 +237,8 @@ static void reader_thread(void *arg) {
   gpr_timespec interval;
   int counter = 0;
   printf("   Reader starting\n");
-  interval = gpr_time_from_micros(args->read_iteration_interval_in_msec * 1000,
-                                  GPR_TIMESPAN);
+  interval = gpr_time_from_micros(
+      (int64_t)args->read_iteration_interval_in_msec * 1000, GPR_TIMESPAN);
   gpr_mu_lock(args->mu);
   while (!args->stop_flag && records_read < args->total_records) {
     gpr_cv_wait(&args->stop, args->mu, interval);
diff --git a/test/core/support/sync_test.c b/test/core/support/sync_test.c
index 0149bc3afd..d311eb136a 100644
--- a/test/core/support/sync_test.c
+++ b/test/core/support/sync_test.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -251,7 +251,7 @@ static void test(const char *name, void (*body)(void *m),
   gpr_timespec start = gpr_now(GPR_CLOCK_REALTIME);
   gpr_timespec time_taken;
   gpr_timespec deadline = gpr_time_add(
-      start, gpr_time_from_micros(timeout_s * 1000000, GPR_TIMESPAN));
+      start, gpr_time_from_micros((int64_t)timeout_s * 1000000, GPR_TIMESPAN));
   fprintf(stderr, "%s:", name);
   while (gpr_time_cmp(gpr_now(GPR_CLOCK_REALTIME), deadline) < 0) {
     iterations <<= 1;
diff --git a/test/core/support/time_test.c b/test/core/support/time_test.c
index fc26f94d29..6cc3786df1 100644
--- a/test/core/support/time_test.c
+++ b/test/core/support/time_test.c
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -125,15 +125,15 @@ static void test_values(void) {
   }
 
   /* Test possible overflow in conversion of -ve values. */
-  x = gpr_time_from_micros(-(LONG_MAX - 999997), GPR_TIMESPAN);
+  x = gpr_time_from_micros(-(INT64_MAX - 999997), GPR_TIMESPAN);
   GPR_ASSERT(x.tv_sec < 0);
   GPR_ASSERT(x.tv_nsec >= 0 && x.tv_nsec < GPR_NS_PER_SEC);
 
-  x = gpr_time_from_nanos(-(LONG_MAX - 999999997), GPR_TIMESPAN);
+  x = gpr_time_from_nanos(-(INT64_MAX - 999999997), GPR_TIMESPAN);
   GPR_ASSERT(x.tv_sec < 0);
   GPR_ASSERT(x.tv_nsec >= 0 && x.tv_nsec < GPR_NS_PER_SEC);
 
-  x = gpr_time_from_millis(-(LONG_MAX - 997), GPR_TIMESPAN);
+  x = gpr_time_from_millis(-(INT64_MAX - 997), GPR_TIMESPAN);
   GPR_ASSERT(x.tv_sec < 0);
   GPR_ASSERT(x.tv_nsec >= 0 && x.tv_nsec < GPR_NS_PER_SEC);
 
diff --git a/test/core/transport/chttp2/timeout_encoding_test.c b/test/core/transport/chttp2/timeout_encoding_test.c
index f0e8ec386f..483e79fb25 100644
--- a/test/core/transport/chttp2/timeout_encoding_test.c
+++ b/test/core/transport/chttp2/timeout_encoding_test.c
@@ -93,7 +93,7 @@ static void assert_decodes_as(const char *buffer, gpr_timespec expected) {
 }
 
 void decode_suite(char ext,
-                  gpr_timespec (*answer)(long x, gpr_clock_type clock)) {
+                  gpr_timespec (*answer)(int64_t x, gpr_clock_type clock)) {
   long test_vals[] = {1,       12,       123,       1234,     12345,   123456,
                       1234567, 12345678, 123456789, 98765432, 9876543, 987654,
                       98765,   9876,     987,       98,       9};
diff --git a/test/core/util/test_config.h b/test/core/util/test_config.h
index 15b71747fb..f6bb2e1f72 100644
--- a/test/core/util/test_config.h
+++ b/test/core/util/test_config.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -54,16 +54,16 @@ extern double g_fixture_slowdown_factor;
   (GRPC_TEST_SLOWDOWN_BUILD_FACTOR * GRPC_TEST_SLOWDOWN_MACHINE_FACTOR * \
    g_fixture_slowdown_factor)
 
-#define GRPC_TIMEOUT_SECONDS_TO_DEADLINE(x)                               \
-  gpr_time_add(                                                           \
-      gpr_now(GPR_CLOCK_MONOTONIC),                                       \
-      gpr_time_from_millis((long)(GRPC_TEST_SLOWDOWN_FACTOR * 1e3 * (x)), \
+#define GRPC_TIMEOUT_SECONDS_TO_DEADLINE(x)                                  \
+  gpr_time_add(                                                              \
+      gpr_now(GPR_CLOCK_MONOTONIC),                                          \
+      gpr_time_from_millis((int64_t)(GRPC_TEST_SLOWDOWN_FACTOR * 1e3 * (x)), \
                            GPR_TIMESPAN))
 
-#define GRPC_TIMEOUT_MILLIS_TO_DEADLINE(x)                                \
-  gpr_time_add(                                                           \
-      gpr_now(GPR_CLOCK_MONOTONIC),                                       \
-      gpr_time_from_micros((long)(GRPC_TEST_SLOWDOWN_FACTOR * 1e3 * (x)), \
+#define GRPC_TIMEOUT_MILLIS_TO_DEADLINE(x)                                   \
+  gpr_time_add(                                                              \
+      gpr_now(GPR_CLOCK_MONOTONIC),                                          \
+      gpr_time_from_micros((int64_t)(GRPC_TEST_SLOWDOWN_FACTOR * 1e3 * (x)), \
                            GPR_TIMESPAN))
 
 #ifndef GRPC_TEST_CUSTOM_PICK_PORT
diff --git a/test/cpp/end2end/thread_stress_test.cc b/test/cpp/end2end/thread_stress_test.cc
index 4c7caa9b87..dd7a8e5ed2 100644
--- a/test/cpp/end2end/thread_stress_test.cc
+++ b/test/cpp/end2end/thread_stress_test.cc
@@ -55,7 +55,9 @@ using grpc::testing::EchoRequest;
 using grpc::testing::EchoResponse;
 using std::chrono::system_clock;
 
-const int kNumThreads = 100;  // Number of threads
+const int kNumThreads = 100; // Number of threads
+const int kNumAsyncSendThreads = 2;
+const int kNumAsyncReceiveThreads = 50;
 const int kNumRpcs = 1000;    // Number of RPCs per thread
 
 namespace grpc {
@@ -273,7 +275,7 @@ class AsyncClientEnd2endTest : public ::testing::Test {
     for (int i = 0; i < num_rpcs; ++i) {
       AsyncClientCall* call = new AsyncClientCall;
       EchoRequest request;
-      request.set_message("Hello");
+      request.set_message("Hello: " + std::to_string(i));
       call->response_reader =
           common_.GetStub()->AsyncEcho(&call->context, request, &cq_);
       call->response_reader->Finish(&call->response, &call->status,
@@ -290,7 +292,9 @@ class AsyncClientEnd2endTest : public ::testing::Test {
       bool ok = false;
       if (!cq_.Next(&got_tag, &ok)) break;
       AsyncClientCall* call = static_cast<AsyncClientCall*>(got_tag);
-      GPR_ASSERT(ok);
+      if (!ok) {
+        gpr_log(GPR_DEBUG, "Error: %d", call->status.error_code());
+      }
       delete call;
 
       bool notify;
@@ -315,22 +319,22 @@ class AsyncClientEnd2endTest : public ::testing::Test {
 TEST_F(AsyncClientEnd2endTest, ThreadStress) {
   common_.ResetStub();
   std::vector<std::thread*> send_threads, completion_threads;
-  for (int i = 0; i < kNumThreads / 2; ++i) {
+  for (int i = 0; i < kNumAsyncReceiveThreads; ++i) {
     completion_threads.push_back(new std::thread(
         &AsyncClientEnd2endTest_ThreadStress_Test::AsyncCompleteRpc, this));
   }
-  for (int i = 0; i < kNumThreads / 2; ++i) {
+  for (int i = 0; i < kNumAsyncSendThreads; ++i) {
     send_threads.push_back(
         new std::thread(&AsyncClientEnd2endTest_ThreadStress_Test::AsyncSendRpc,
                         this, kNumRpcs));
   }
-  for (int i = 0; i < kNumThreads / 2; ++i) {
+  for (int i = 0; i < kNumAsyncSendThreads; ++i) {
     send_threads[i]->join();
     delete send_threads[i];
   }
 
   Wait();
-  for (int i = 0; i < kNumThreads / 2; ++i) {
+  for (int i = 0; i < kNumAsyncReceiveThreads; ++i) {
     completion_threads[i]->join();
     delete completion_threads[i];
   }
diff --git a/test/cpp/qps/client_async.cc b/test/cpp/qps/client_async.cc
index 6b6294ba51..f3f8f37051 100644
--- a/test/cpp/qps/client_async.cc
+++ b/test/cpp/qps/client_async.cc
@@ -96,8 +96,7 @@ class ClientRpcContextUnaryImpl : public ClientRpcContext {
       std::function<
           std::unique_ptr<grpc::ClientAsyncResponseReader<ResponseType>>(
               BenchmarkService::Stub*, grpc::ClientContext*, const RequestType&,
-              CompletionQueue*)>
-          start_req,
+              CompletionQueue*)> start_req,
       std::function<void(grpc::Status, ResponseType*)> on_done)
       : ClientRpcContext(channel_id),
         context_(),
@@ -143,8 +142,7 @@ class ClientRpcContextUnaryImpl : public ClientRpcContext {
   std::function<void(grpc::Status, ResponseType*)> callback_;
   std::function<std::unique_ptr<grpc::ClientAsyncResponseReader<ResponseType>>(
       BenchmarkService::Stub*, grpc::ClientContext*, const RequestType&,
-      CompletionQueue*)>
-      start_req_;
+      CompletionQueue*)> start_req_;
   grpc::Status status_;
   double start_;
   std::unique_ptr<grpc::ClientAsyncResponseReader<ResponseType>>
@@ -164,12 +162,11 @@ class AsyncClient : public ClientImpl<StubType, RequestType> {
   using ClientImpl<StubType, RequestType>::cores_;
   using ClientImpl<StubType, RequestType>::channels_;
   using ClientImpl<StubType, RequestType>::request_;
-  AsyncClient(
-      const ClientConfig& config,
-      std::function<ClientRpcContext*(int, StubType*, const RequestType&)>
-          setup_ctx,
-      std::function<std::unique_ptr<StubType>(std::shared_ptr<Channel>)>
-          create_stub)
+  AsyncClient(const ClientConfig& config,
+              std::function<ClientRpcContext*(int, StubType*,
+                                              const RequestType&)> setup_ctx,
+              std::function<std::unique_ptr<StubType>(std::shared_ptr<Channel>)>
+                  create_stub)
       : ClientImpl<StubType, RequestType>(config, create_stub),
         num_async_threads_(NumThreads(config)),
         channel_lock_(new std::mutex[config.client_channels()]),
@@ -411,8 +408,7 @@ class ClientRpcContextStreamingImpl : public ClientRpcContext {
       std::function<std::unique_ptr<
           grpc::ClientAsyncReaderWriter<RequestType, ResponseType>>(
           BenchmarkService::Stub*, grpc::ClientContext*, CompletionQueue*,
-          void*)>
-          start_req,
+          void*)> start_req,
       std::function<void(grpc::Status, ResponseType*)> on_done)
       : ClientRpcContext(channel_id),
         context_(),
@@ -464,10 +460,10 @@ class ClientRpcContextStreamingImpl : public ClientRpcContext {
   ResponseType response_;
   bool (ClientRpcContextStreamingImpl::*next_state_)(bool, Histogram*);
   std::function<void(grpc::Status, ResponseType*)> callback_;
-  std::function<std::unique_ptr<
-      grpc::ClientAsyncReaderWriter<RequestType, ResponseType>>(
-      BenchmarkService::Stub*, grpc::ClientContext*, CompletionQueue*, void*)>
-      start_req_;
+  std::function<
+      std::unique_ptr<grpc::ClientAsyncReaderWriter<RequestType, ResponseType>>(
+          BenchmarkService::Stub*, grpc::ClientContext*, CompletionQueue*,
+          void*)> start_req_;
   grpc::Status status_;
   double start_;
   std::unique_ptr<grpc::ClientAsyncReaderWriter<RequestType, ResponseType>>
@@ -511,8 +507,7 @@ class ClientRpcContextGenericStreamingImpl : public ClientRpcContext {
       int channel_id, grpc::GenericStub* stub, const ByteBuffer& req,
       std::function<std::unique_ptr<grpc::GenericClientAsyncReaderWriter>(
           grpc::GenericStub*, grpc::ClientContext*,
-          const grpc::string& method_name, CompletionQueue*, void*)>
-          start_req,
+          const grpc::string& method_name, CompletionQueue*, void*)> start_req,
       std::function<void(grpc::Status, ByteBuffer*)> on_done)
       : ClientRpcContext(channel_id),
         context_(),
@@ -569,8 +564,7 @@ class ClientRpcContextGenericStreamingImpl : public ClientRpcContext {
   std::function<void(grpc::Status, ByteBuffer*)> callback_;
   std::function<std::unique_ptr<grpc::GenericClientAsyncReaderWriter>(
       grpc::GenericStub*, grpc::ClientContext*, const grpc::string&,
-      CompletionQueue*, void*)>
-      start_req_;
+      CompletionQueue*, void*)> start_req_;
   grpc::Status status_;
   double start_;
   std::unique_ptr<grpc::GenericClientAsyncReaderWriter> stream_;
diff --git a/test/cpp/qps/driver.h b/test/cpp/qps/driver.h
index 4b2b400c0c..3af61f7391 100644
--- a/test/cpp/qps/driver.h
+++ b/test/cpp/qps/driver.h
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
diff --git a/test/cpp/util/time_test.cc b/test/cpp/util/time_test.cc
index 1e501dfd28..48c6ce7697 100644
--- a/test/cpp/util/time_test.cc
+++ b/test/cpp/util/time_test.cc
@@ -1,6 +1,6 @@
 /*
  *
- * Copyright 2015, Google Inc.
+ * Copyright 2015-2016, Google Inc.
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -45,7 +45,7 @@ namespace {
 class TimeTest : public ::testing::Test {};
 
 TEST_F(TimeTest, AbsolutePointTest) {
-  long us = 10000000L;
+  int64_t us = 10000000L;
   gpr_timespec ts = gpr_time_from_micros(us, GPR_TIMESPAN);
   ts.clock_type = GPR_CLOCK_REALTIME;
   system_clock::time_point tp{microseconds(us)};
diff --git a/test/distrib/csharp/run_distrib_test.sh b/test/distrib/csharp/run_distrib_test.sh
index 5a01c91875..8ddb4c4bff 100755
--- a/test/distrib/csharp/run_distrib_test.sh
+++ b/test/distrib/csharp/run_distrib_test.sh
@@ -32,7 +32,7 @@ set -ex
 
 cd $(dirname $0)
 
-unzip "$EXTERNAL_GIT_ROOT/input_artifacts/csharp_nugets.zip" -d TestNugetFeed
+unzip -o "$EXTERNAL_GIT_ROOT/input_artifacts/csharp_nugets.zip" -d TestNugetFeed
 
 # TODO(jtattermusch): replace the version number
 ./update_version.sh 0.13.0
diff --git a/test/distrib/csharp/update_version.sh b/test/distrib/csharp/update_version.sh
index 569f7ff4bd..f2554e8998 100755
--- a/test/distrib/csharp/update_version.sh
+++ b/test/distrib/csharp/update_version.sh
@@ -33,4 +33,4 @@ set -e
 cd $(dirname $0)
 
 # Replaces version placeholder with value provided as first argument.
-sed -i "s/__GRPC_NUGET_VERSION__/$1/g" DistribTest/packages.config DistribTest/DistribTest.csproj
+sed -ibak "s/__GRPC_NUGET_VERSION__/$1/g" DistribTest/packages.config DistribTest/DistribTest.csproj
diff --git a/test/distrib/node/run_distrib_test.sh b/test/distrib/node/run_distrib_test.sh
index 90637cc01d..ac9e7d7090 100755
--- a/test/distrib/node/run_distrib_test.sh
+++ b/test/distrib/node/run_distrib_test.sh
@@ -32,7 +32,12 @@ set -ex
 
 cd $(dirname $0)
 
-nvm install $1
+NODE_VERSION="$1"
+
+# make sure nvm is available
+source ~/.nvm/nvm.sh || true
+
+nvm install $NODE_VERSION
 
 npm install -g node-static
 
diff --git a/test/distrib/python/distribtest.py b/test/distrib/python/distribtest.py
index 428ffe2b34..66c1f88796 100644
--- a/test/distrib/python/distribtest.py
+++ b/test/distrib/python/distribtest.py
@@ -1,3 +1,32 @@
+# Copyright 2015-2016, 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.
+
 from grpc.beta import implementations
 
 # This code doesn't do much but makes sure the native extension is loaded
diff --git a/test/distrib/python/run_distrib_test.sh b/test/distrib/python/run_distrib_test.sh
index a185bcbc26..08856ad388 100755
--- a/test/distrib/python/run_distrib_test.sh
+++ b/test/distrib/python/run_distrib_test.sh
@@ -42,17 +42,17 @@ then
   exit 1
 fi
 
-# TODO(jtattermusch): this shouldn't be required
-pip install --upgrade six
+PIP=pip2
+which $PIP || PIP=pip
+PYTHON=python2
+which $PYTHON || PYTHON=python
 
-# TODO(jtattermusch): if these don't get preinstalled, pip tries to install them
-# with --use-grpc-custom-bdist option, which obviously fails.
-pip install --upgrade enum34
-pip install --upgrade futures
+# TODO(jtattermusch): this shouldn't be required
+$PIP install --upgrade six
 
 GRPC_PYTHON_BINARIES_REPOSITORY="${BDIST_DIR}" \
-    pip install \
-    "${SDIST_ARCHIVE}" \
-    --install-option="--use-grpc-custom-bdist"
+    $PIP install \
+    "${SDIST_ARCHIVE}"
+
+$PYTHON distribtest.py
 
-python distribtest.py
diff --git a/third_party/rake-compiler-dock/Dockerfile b/third_party/rake-compiler-dock/Dockerfile
index 28623c3028..a8f5b8a116 100644
--- a/third_party/rake-compiler-dock/Dockerfile
+++ b/third_party/rake-compiler-dock/Dockerfile
@@ -1,7 +1,7 @@
 FROM ubuntu:14.04
 
 RUN apt-get -y update && \
-    apt-get install -y curl git-core mingw-w64 xz-utils build-essential wget unzip
+    apt-get install -y curl git-core mingw-w64 xz-utils build-essential gcc-multilib wget unzip
 
 RUN mkdir -p /opt/mingw && \
     curl -SL http://downloads.sourceforge.net/mingw-w64/i686-w64-mingw32-gcc-4.7.2-release-linux64_rubenvb.tar.xz | \
@@ -103,12 +103,25 @@ RUN bash -c "rvm use 2.3.0 --default && \
     export MAKE=\"make -j`nproc`\" CFLAGS='-s -O1 -fno-omit-frame-pointer -fno-fast-math' && \
     rake-compiler cross-ruby VERSION=2.3.0 HOST=i686-w64-mingw32 && \
     rake-compiler cross-ruby VERSION=2.3.0 HOST=x86_64-w64-mingw32 && \
+    rake-compiler cross-ruby VERSION=2.3.0 HOST=x86_64-linux-gnu && \
     rake-compiler cross-ruby VERSION=2.2.2 HOST=i686-w64-mingw32 && \
     rake-compiler cross-ruby VERSION=2.2.2 HOST=x86_64-w64-mingw32 && \
-    rake-compiler cross-ruby VERSION=2.1.6 HOST=i686-w64-mingw32 && \
-    rake-compiler cross-ruby VERSION=2.1.6 HOST=x86_64-w64-mingw32 && \
+    rake-compiler cross-ruby VERSION=2.2.2 HOST=x86_64-linux-gnu && \
+    rake-compiler cross-ruby VERSION=2.1.5 HOST=i686-w64-mingw32 && \
+    rake-compiler cross-ruby VERSION=2.1.5 HOST=x86_64-w64-mingw32 && \
+    rake-compiler cross-ruby VERSION=2.1.5 HOST=x86_64-linux-gnu && \
     rake-compiler cross-ruby VERSION=2.0.0-p645 HOST=i686-w64-mingw32 && \
     rake-compiler cross-ruby VERSION=2.0.0-p645 HOST=x86_64-w64-mingw32 && \
+    rake-compiler cross-ruby VERSION=2.0.0-p645 HOST=x86_64-linux-gnu && \
+    rm -rf ~/.rake-compiler/tmp/builds ~/.rake-compiler/sources && \
+    find /usr/local/rvm -type d -print0 | sudo xargs -0 chmod g+sw "
+
+RUN bash -c "rvm use 2.3.0 --default && \
+    export MAKE=\"make -j`nproc`\" CFLAGS='-m32 -s -O1 -fno-omit-frame-pointer -fno-fast-math' LDFLAGS='-m32' && \
+    rake-compiler cross-ruby VERSION=2.3.0 HOST=i686-linux-gnu && \
+    rake-compiler cross-ruby VERSION=2.2.2 HOST=i686-linux-gnu && \
+    rake-compiler cross-ruby VERSION=2.1.5 HOST=i686-linux-gnu && \
+    rake-compiler cross-ruby VERSION=2.0.0-p645 HOST=i686-linux-gnu && \
     rm -rf ~/.rake-compiler/tmp/builds ~/.rake-compiler/sources && \
     find /usr/local/rvm -type d -print0 | sudo xargs -0 chmod g+sw "
 
@@ -151,6 +164,6 @@ RUN cp /tmp/build/runas /usr/local/bin/
 # Install sudoers configuration
 RUN cp /tmp/build/sudoers /etc/sudoers.d/rake-compiler-dock
 
-ENV RUBY_CC_VERSION 2.3.0:2.2.2:2.1.6:2.0.0
+ENV RUBY_CC_VERSION 2.3.0:2.2.2:2.1.5:2.0.0
 
 CMD bash
diff --git a/tools/distrib/build_ruby_environment_macos.sh b/tools/distrib/build_ruby_environment_macos.sh
new file mode 100644
index 0000000000..ff3a388eaf
--- /dev/null
+++ b/tools/distrib/build_ruby_environment_macos.sh
@@ -0,0 +1,61 @@
+#!/bin/bash
+# Copyright 2015-2016, 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.
+
+set -ex
+
+rm -rf ~/.rake-compiler
+
+CROSS_RUBY=`mktemp tmpfile.XXXXXXXX`
+
+curl https://raw.githubusercontent.com/rake-compiler/rake-compiler/v0.9.5/tasks/bin/cross-ruby.rake > $CROSS_RUBY
+
+patch $CROSS_RUBY << EOF
+--- cross-ruby.rake	2016-02-05 16:26:53.000000000 -0800
++++ cross-ruby.rake.patched	2016-02-05 16:27:33.000000000 -0800
+@@ -133,7 +133,8 @@
+     "--host=#{MINGW_HOST}",
+     "--target=#{MINGW_TARGET}",
+     "--build=#{RUBY_BUILD}",
+-    '--enable-shared',
++    '--enable-static',
++    '--disable-shared',
+     '--disable-install-doc',
+     '--without-tk',
+     '--without-tcl'
+EOF
+
+MAKE="make -j8"
+
+for v in 2.3.0 2.2.2 2.1.5 2.0.0-p645 ; do
+  rake -f $CROSS_RUBY cross-ruby VERSION=$v HOST=x86_64-darwin11
+done
+
+sed 's/x86_64-darwin-11/universal-darwin/' ~/.rake-compiler/config.yml > $CROSS_RUBY
+mv $CROSS_RUBY ~/.rake-compiler/config.yml
diff --git a/tools/dockerfile/distribtest/csharp_centos7_x64/Dockerfile b/tools/dockerfile/distribtest/csharp_centos7_x64/Dockerfile
index 17e9698904..03b5b364f8 100644
--- a/tools/dockerfile/distribtest/csharp_centos7_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/csharp_centos7_x64/Dockerfile
@@ -33,6 +33,5 @@ RUN rpm --import "http://keyserver.ubuntu.com/pks/lookup?op=get&search=0x3FA7E03
 RUN yum-config-manager --add-repo http://download.mono-project.com/repo/centos/
 
 RUN yum install -y mono
-RUN yum install -y git
 RUN yum install -y unzip
 RUN yum install -y nuget
diff --git a/tools/dockerfile/distribtest/csharp_jessie_x64/Dockerfile b/tools/dockerfile/distribtest/csharp_jessie_x64/Dockerfile
index 840ecf0fc2..1cadba3b7b 100644
--- a/tools/dockerfile/distribtest/csharp_jessie_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/csharp_jessie_x64/Dockerfile
@@ -40,4 +40,4 @@ RUN apt-get update && apt-get install -y \
     ca-certificates-mono \
     nuget
 
-RUN apt-get update && apt-get install -y git unzip
+RUN apt-get update && apt-get install -y unzip
diff --git a/tools/dockerfile/distribtest/csharp_jessie_x86/Dockerfile b/tools/dockerfile/distribtest/csharp_jessie_x86/Dockerfile
index 3a50da4936..be962828c2 100644
--- a/tools/dockerfile/distribtest/csharp_jessie_x86/Dockerfile
+++ b/tools/dockerfile/distribtest/csharp_jessie_x86/Dockerfile
@@ -40,4 +40,4 @@ RUN apt-get update && apt-get install -y \
     ca-certificates-mono \
     nuget
 
-RUN apt-get update && apt-get install -y git unzip
+RUN apt-get update && apt-get install -y unzip
diff --git a/tools/dockerfile/distribtest/csharp_ubuntu1404_x64/Dockerfile b/tools/dockerfile/distribtest/csharp_ubuntu1404_x64/Dockerfile
index 901c981acb..3d04d032b5 100644
--- a/tools/dockerfile/distribtest/csharp_ubuntu1404_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/csharp_ubuntu1404_x64/Dockerfile
@@ -37,4 +37,4 @@ RUN apt-get update && apt-get install -y \
     ca-certificates-mono \
     nuget
 
-RUN apt-get update && apt-get install -y git unzip
+RUN apt-get update && apt-get install -y unzip
diff --git a/tools/dockerfile/distribtest/csharp_ubuntu1504_x64/Dockerfile b/tools/dockerfile/distribtest/csharp_ubuntu1504_x64/Dockerfile
index 1b8d454681..5eec570491 100644
--- a/tools/dockerfile/distribtest/csharp_ubuntu1504_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/csharp_ubuntu1504_x64/Dockerfile
@@ -37,4 +37,4 @@ RUN apt-get update && apt-get install -y \
     ca-certificates-mono \
     nuget
 
-RUN apt-get update && apt-get install -y git unzip
+RUN apt-get update && apt-get install -y unzip
diff --git a/tools/dockerfile/distribtest/csharp_ubuntu1510_x64/Dockerfile b/tools/dockerfile/distribtest/csharp_ubuntu1510_x64/Dockerfile
index a6c26a4b9e..a6d60fb4b9 100644
--- a/tools/dockerfile/distribtest/csharp_ubuntu1510_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/csharp_ubuntu1510_x64/Dockerfile
@@ -37,4 +37,4 @@ RUN apt-get update && apt-get install -y \
     ca-certificates-mono \
     nuget
 
-RUN apt-get update && apt-get install -y git unzip
+RUN apt-get update && apt-get install -y unzip
diff --git a/tools/dockerfile/distribtest/csharp_ubuntu1604_x64/Dockerfile b/tools/dockerfile/distribtest/csharp_ubuntu1604_x64/Dockerfile
index c6a8634937..61472704d7 100644
--- a/tools/dockerfile/distribtest/csharp_ubuntu1604_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/csharp_ubuntu1604_x64/Dockerfile
@@ -34,4 +34,4 @@ RUN apt-get update && apt-get install -y \
     ca-certificates-mono \
     nuget
 
-RUN apt-get update && apt-get install -y git unzip
+RUN apt-get update && apt-get install -y unzip
diff --git a/tools/dockerfile/distribtest/csharp_wheezy_x64/Dockerfile b/tools/dockerfile/distribtest/csharp_wheezy_x64/Dockerfile
index dd865e8bbc..9039c3c509 100644
--- a/tools/dockerfile/distribtest/csharp_wheezy_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/csharp_wheezy_x64/Dockerfile
@@ -29,4 +29,4 @@
 
 FROM mono:4.2.2.30
 
-RUN apt-get update && apt-get install -y git unzip
+RUN apt-get update && apt-get install -y unzip
diff --git a/tools/dockerfile/distribtest/node_centos7_x64/Dockerfile b/tools/dockerfile/distribtest/node_centos7_x64/Dockerfile
index 9c1f5ee729..f6e1664086 100644
--- a/tools/dockerfile/distribtest/node_centos7_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/node_centos7_x64/Dockerfile
@@ -29,7 +29,6 @@
 
 FROM centos:7
 
-RUN yum install -y git
 RUN yum install -y curl
 
 # Install nvm
diff --git a/tools/dockerfile/distribtest/node_jessie_x64/Dockerfile b/tools/dockerfile/distribtest/node_jessie_x64/Dockerfile
index 69a071500e..4ca5e86563 100644
--- a/tools/dockerfile/distribtest/node_jessie_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/node_jessie_x64/Dockerfile
@@ -29,7 +29,7 @@
 
 FROM debian:jessie
 
-RUN apt-get update && apt-get install -y curl git
+RUN apt-get update && apt-get install -y curl
 
 # Install nvm
 RUN touch .profile
diff --git a/tools/dockerfile/distribtest/node_jessie_x86/Dockerfile b/tools/dockerfile/distribtest/node_jessie_x86/Dockerfile
index 173c70360d..8b97d8bb5a 100644
--- a/tools/dockerfile/distribtest/node_jessie_x86/Dockerfile
+++ b/tools/dockerfile/distribtest/node_jessie_x86/Dockerfile
@@ -29,8 +29,8 @@
 
 FROM 32bit/debian:jessie
 
-RUN apt-get update && apt-get install -y curl git
+RUN apt-get update && apt-get install -y curl
 
 # Install nvm
 RUN touch .profile
-RUN curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.30.2/install.sh | bash
\ No newline at end of file
+RUN curl -o- https://raw.githubusercontent.com/creationix/nvm/v0.30.2/install.sh | bash
diff --git a/tools/dockerfile/distribtest/node_ubuntu1204_x64/Dockerfile b/tools/dockerfile/distribtest/node_ubuntu1204_x64/Dockerfile
index c53a4aa305..0134dc964e 100644
--- a/tools/dockerfile/distribtest/node_ubuntu1204_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/node_ubuntu1204_x64/Dockerfile
@@ -29,7 +29,7 @@
 
 FROM ubuntu:12.04
 
-RUN apt-get update && apt-get install -y curl git
+RUN apt-get update && apt-get install -y curl
 
 # Install nvm
 RUN touch .profile
diff --git a/tools/dockerfile/distribtest/node_ubuntu1404_x64/Dockerfile b/tools/dockerfile/distribtest/node_ubuntu1404_x64/Dockerfile
index 8fe6ae1f33..0fae447946 100644
--- a/tools/dockerfile/distribtest/node_ubuntu1404_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/node_ubuntu1404_x64/Dockerfile
@@ -29,7 +29,7 @@
 
 FROM ubuntu:14.04
 
-RUN apt-get update && apt-get install -y curl git
+RUN apt-get update && apt-get install -y curl
 
 # Install nvm
 RUN touch .profile
diff --git a/tools/dockerfile/distribtest/node_ubuntu1504_x64/Dockerfile b/tools/dockerfile/distribtest/node_ubuntu1504_x64/Dockerfile
index 013c2a0c72..55da46c3be 100644
--- a/tools/dockerfile/distribtest/node_ubuntu1504_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/node_ubuntu1504_x64/Dockerfile
@@ -29,7 +29,7 @@
 
 FROM ubuntu:15.04
 
-RUN apt-get update && apt-get install -y curl git
+RUN apt-get update && apt-get install -y curl
 
 # Install nvm
 RUN touch .profile
diff --git a/tools/dockerfile/distribtest/node_ubuntu1510_x64/Dockerfile b/tools/dockerfile/distribtest/node_ubuntu1510_x64/Dockerfile
index 43b3ae2738..c050cab7d3 100644
--- a/tools/dockerfile/distribtest/node_ubuntu1510_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/node_ubuntu1510_x64/Dockerfile
@@ -29,7 +29,7 @@
 
 FROM ubuntu:15.10
 
-RUN apt-get update && apt-get install -y curl git
+RUN apt-get update && apt-get install -y curl
 
 # Install nvm
 RUN touch .profile
diff --git a/tools/dockerfile/distribtest/node_ubuntu1604_x64/Dockerfile b/tools/dockerfile/distribtest/node_ubuntu1604_x64/Dockerfile
index 3eae75475c..ab9e8a32e3 100644
--- a/tools/dockerfile/distribtest/node_ubuntu1604_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/node_ubuntu1604_x64/Dockerfile
@@ -29,7 +29,7 @@
 
 FROM ubuntu:16.04
 
-RUN apt-get update && apt-get install -y curl git
+RUN apt-get update && apt-get install -y curl
 
 # Install nvm
 RUN touch .profile
diff --git a/tools/dockerfile/distribtest/python_arch_x64/Dockerfile b/tools/dockerfile/distribtest/python_arch_x64/Dockerfile
index 4d10e240c6..c4f2431080 100644
--- a/tools/dockerfile/distribtest/python_arch_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/python_arch_x64/Dockerfile
@@ -30,7 +30,7 @@
 FROM base/archlinux
 
 RUN pacman --noconfirm -Syy
-RUN pacman --noconfirm -S git
-RUN pacman --noconfirm -S python
-RUN pacman --noconfirm -S python-pip
+RUN pacman --noconfirm -S openssl
+RUN pacman --noconfirm -S python2
+RUN pacman --noconfirm -S python2-pip
 
diff --git a/tools/dockerfile/distribtest/python_centos6_x64/Dockerfile b/tools/dockerfile/distribtest/python_centos6_x64/Dockerfile
index 683686c6db..99306bb403 100644
--- a/tools/dockerfile/distribtest/python_centos6_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/python_centos6_x64/Dockerfile
@@ -29,9 +29,10 @@
 
 FROM centos:6
 
-RUN yum install -y git
 RUN yum install -y python
 
 RUN rpm -ivh http://dl.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
 RUN yum install -y python-pip
 
+RUN pip install --upgrade pip
+
diff --git a/tools/dockerfile/distribtest/python_centos7_x64/Dockerfile b/tools/dockerfile/distribtest/python_centos7_x64/Dockerfile
index 6b70f65f10..114957b573 100644
--- a/tools/dockerfile/distribtest/python_centos7_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/python_centos7_x64/Dockerfile
@@ -29,7 +29,6 @@
 
 FROM centos:7
 
-RUN yum install -y git
 RUN yum install -y python
 RUN yum install -y epel-release
 RUN yum install -y python-pip
diff --git a/tools/dockerfile/distribtest/python_fedora20_x64/Dockerfile b/tools/dockerfile/distribtest/python_fedora20_x64/Dockerfile
index 1c91594363..d58036410f 100644
--- a/tools/dockerfile/distribtest/python_fedora20_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/python_fedora20_x64/Dockerfile
@@ -29,9 +29,4 @@
 
 FROM fedora:20
 
-RUN yum clean all
-RUN yum update -y
-RUN yum install -y git
-RUN yum install -y python
-RUN yum install -y python-pip
-
+RUN yum clean all && yum update -y && yum install -y python python-pip
diff --git a/tools/dockerfile/distribtest/python_fedora21_x64/Dockerfile b/tools/dockerfile/distribtest/python_fedora21_x64/Dockerfile
index e35de109ea..b44fcff7e3 100644
--- a/tools/dockerfile/distribtest/python_fedora21_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/python_fedora21_x64/Dockerfile
@@ -29,9 +29,4 @@
 
 FROM fedora:21
 
-RUN yum clean all
-RUN yum update -y
-RUN yum install -y git
-RUN yum install -y python
-RUN yum install -y python-pip
-
+RUN yum clean all && yum update -y && yum install -y python python-pip
diff --git a/tools/dockerfile/distribtest/python_fedora22_x64/Dockerfile b/tools/dockerfile/distribtest/python_fedora22_x64/Dockerfile
index 69c3b541d3..c6415946c3 100644
--- a/tools/dockerfile/distribtest/python_fedora22_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/python_fedora22_x64/Dockerfile
@@ -29,9 +29,4 @@
 
 FROM fedora:22
 
-RUN yum clean all
-RUN yum update -y
-RUN yum install -y git
-RUN yum install -y python
-RUN yum install -y python-pip
-
+RUN yum clean all && yum update -y && yum install -y python python-pip
diff --git a/tools/dockerfile/distribtest/python_fedora23_x64/Dockerfile b/tools/dockerfile/distribtest/python_fedora23_x64/Dockerfile
index 74639a3118..6c834d2bc2 100644
--- a/tools/dockerfile/distribtest/python_fedora23_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/python_fedora23_x64/Dockerfile
@@ -29,9 +29,4 @@
 
 FROM fedora:23
 
-RUN yum clean all
-RUN yum update -y
-RUN yum install -y git
-RUN yum install -y python
-RUN yum install -y python-pip
-
+RUN yum clean all && yum update -y && yum install -y python python-pip
diff --git a/tools/dockerfile/distribtest/python_jessie_x64/Dockerfile b/tools/dockerfile/distribtest/python_jessie_x64/Dockerfile
index 3d511e267a..5778d604c8 100644
--- a/tools/dockerfile/distribtest/python_jessie_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/python_jessie_x64/Dockerfile
@@ -29,6 +29,4 @@
 
 FROM debian:jessie
 
-RUN apt-get update
-RUN apt-get install -y git python python-pip
-
+RUN apt-get update && apt-get install -y python python-pip
diff --git a/tools/dockerfile/distribtest/python_jessie_x86/Dockerfile b/tools/dockerfile/distribtest/python_jessie_x86/Dockerfile
index 035d56b655..e9cf99142b 100644
--- a/tools/dockerfile/distribtest/python_jessie_x86/Dockerfile
+++ b/tools/dockerfile/distribtest/python_jessie_x86/Dockerfile
@@ -29,6 +29,9 @@
 
 FROM 32bit/debian:jessie
 
-RUN apt-get update
-RUN apt-get install -y git python python-pip
+RUN apt-get update && apt-get install -y python python-pip
 
+# docker is running on a 64-bit machine, so we need to
+# override "uname -m" to report i686 instead of x86_64, otherwise
+# python will choose a wrong binary package to install.
+ENTRYPOINT ["linux32"]
diff --git a/tools/dockerfile/distribtest/python_opensuse_x64/Dockerfile b/tools/dockerfile/distribtest/python_opensuse_x64/Dockerfile
index 032beb97e5..417d9e0293 100644
--- a/tools/dockerfile/distribtest/python_opensuse_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/python_opensuse_x64/Dockerfile
@@ -29,7 +29,5 @@
 
 FROM opensuse:42.1
 
-RUN zypper --non-interactive install git
 RUN zypper --non-interactive install python
 RUN zypper --non-interactive install python-pip
-
diff --git a/tools/dockerfile/distribtest/python_ubuntu1204_x64/Dockerfile b/tools/dockerfile/distribtest/python_ubuntu1204_x64/Dockerfile
index 9dbf90f511..a48ce0eeef 100644
--- a/tools/dockerfile/distribtest/python_ubuntu1204_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/python_ubuntu1204_x64/Dockerfile
@@ -29,8 +29,4 @@
 
 FROM ubuntu:12.04
 
-RUN apt-get update -y
-RUN apt-get install -y git
-RUN apt-get install -y python
-RUN apt-get install -y python-pip
-
+RUN apt-get update -y && apt-get install -y python python-pip
diff --git a/tools/dockerfile/distribtest/python_ubuntu1404_x64/Dockerfile b/tools/dockerfile/distribtest/python_ubuntu1404_x64/Dockerfile
index 3b366a9bb4..18dbfd4657 100644
--- a/tools/dockerfile/distribtest/python_ubuntu1404_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/python_ubuntu1404_x64/Dockerfile
@@ -29,8 +29,4 @@
 
 FROM ubuntu:14.04
 
-RUN apt-get update -y
-RUN apt-get install -y git
-RUN apt-get install -y python
-RUN apt-get install -y python-pip
-
+RUN apt-get update -y && apt-get install -y python python-pip
diff --git a/tools/dockerfile/distribtest/python_ubuntu1504_x64/Dockerfile b/tools/dockerfile/distribtest/python_ubuntu1504_x64/Dockerfile
index de90b5b7e2..444a54d14b 100644
--- a/tools/dockerfile/distribtest/python_ubuntu1504_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/python_ubuntu1504_x64/Dockerfile
@@ -29,8 +29,4 @@
 
 FROM ubuntu:15.04
 
-RUN apt-get update -y
-RUN apt-get install -y git
-RUN apt-get install -y python
-RUN apt-get install -y python-pip
-
+RUN apt-get update -y && apt-get install -y python python-pip
diff --git a/tools/dockerfile/distribtest/python_ubuntu1510_x64/Dockerfile b/tools/dockerfile/distribtest/python_ubuntu1510_x64/Dockerfile
index d10e04aacc..245ffb9413 100644
--- a/tools/dockerfile/distribtest/python_ubuntu1510_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/python_ubuntu1510_x64/Dockerfile
@@ -29,8 +29,4 @@
 
 FROM ubuntu:15.10
 
-RUN apt-get update -y
-RUN apt-get install -y git
-RUN apt-get install -y python
-RUN apt-get install -y python-pip
-
+RUN apt-get update -y && apt-get install -y python python-pip
diff --git a/tools/dockerfile/distribtest/python_ubuntu1604_x64/Dockerfile b/tools/dockerfile/distribtest/python_ubuntu1604_x64/Dockerfile
index bc56285a3d..a1ac3051ba 100644
--- a/tools/dockerfile/distribtest/python_ubuntu1604_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/python_ubuntu1604_x64/Dockerfile
@@ -29,8 +29,4 @@
 
 FROM ubuntu:16.04
 
-RUN apt-get update -y
-RUN apt-get install -y git
-RUN apt-get install -y python
-RUN apt-get install -y python-pip
-
+RUN apt-get update -y && apt-get install -y python python-pip
diff --git a/tools/dockerfile/distribtest/python_wheezy_x64/Dockerfile b/tools/dockerfile/distribtest/python_wheezy_x64/Dockerfile
index 895dd96747..46353b92d6 100644
--- a/tools/dockerfile/distribtest/python_wheezy_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/python_wheezy_x64/Dockerfile
@@ -29,6 +29,4 @@
 
 FROM debian:wheezy
 
-RUN apt-get update
-RUN apt-get install -y git python python-pip
-
+RUN apt-get update -y && apt-get install -y python python-pip
diff --git a/tools/dockerfile/distribtest/ruby_centos6_x64/Dockerfile b/tools/dockerfile/distribtest/ruby_centos6_x64/Dockerfile
index 28a5c4ad71..fd2cf63a59 100644
--- a/tools/dockerfile/distribtest/ruby_centos6_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/ruby_centos6_x64/Dockerfile
@@ -29,6 +29,4 @@
 
 FROM centos:6
 
-RUN yum install -y git
 RUN yum install -y ruby
-
diff --git a/tools/dockerfile/distribtest/ruby_centos7_x64/Dockerfile b/tools/dockerfile/distribtest/ruby_centos7_x64/Dockerfile
index bdc100ee1c..5bb9bd6fa6 100644
--- a/tools/dockerfile/distribtest/ruby_centos7_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/ruby_centos7_x64/Dockerfile
@@ -29,6 +29,4 @@
 
 FROM centos:7
 
-RUN yum install -y git
 RUN yum install -y ruby
-
diff --git a/tools/dockerfile/distribtest/ruby_fedora20_x64/Dockerfile b/tools/dockerfile/distribtest/ruby_fedora20_x64/Dockerfile
index 50ff0b038b..9f23be986f 100644
--- a/tools/dockerfile/distribtest/ruby_fedora20_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/ruby_fedora20_x64/Dockerfile
@@ -29,8 +29,4 @@
 
 FROM fedora:20
 
-RUN yum clean all
-RUN yum update -y
-RUN yum install -y git
-RUN yum install -y ruby
-
+RUN yum clean all && yum update -y && yum install -y ruby
diff --git a/tools/dockerfile/distribtest/ruby_fedora21_x64/Dockerfile b/tools/dockerfile/distribtest/ruby_fedora21_x64/Dockerfile
index 219ecc8b53..57106a4894 100644
--- a/tools/dockerfile/distribtest/ruby_fedora21_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/ruby_fedora21_x64/Dockerfile
@@ -29,8 +29,4 @@
 
 FROM fedora:21
 
-RUN yum clean all
-RUN yum update -y
-RUN yum install -y git
-RUN yum install -y ruby
-
+RUN yum clean all && yum update -y && yum install -y ruby
diff --git a/tools/dockerfile/distribtest/ruby_fedora22_x64/Dockerfile b/tools/dockerfile/distribtest/ruby_fedora22_x64/Dockerfile
index 49d4c7d7f8..d770177381 100644
--- a/tools/dockerfile/distribtest/ruby_fedora22_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/ruby_fedora22_x64/Dockerfile
@@ -29,8 +29,4 @@
 
 FROM fedora:22
 
-RUN yum clean all
-RUN yum update -y
-RUN yum install -y git
-RUN yum install -y ruby
-
+RUN yum clean all && yum update -y && yum install -y ruby
diff --git a/tools/dockerfile/distribtest/ruby_fedora23_x64/Dockerfile b/tools/dockerfile/distribtest/ruby_fedora23_x64/Dockerfile
index 3c5363fb63..2c9b78ed08 100644
--- a/tools/dockerfile/distribtest/ruby_fedora23_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/ruby_fedora23_x64/Dockerfile
@@ -29,8 +29,4 @@
 
 FROM fedora:23
 
-RUN yum clean all
-RUN yum update -y
-RUN yum install -y git
-RUN yum install -y ruby
-
+RUN yum clean all && yum update -y && yum install -y ruby
diff --git a/tools/dockerfile/distribtest/ruby_jessie_x64/Dockerfile b/tools/dockerfile/distribtest/ruby_jessie_x64/Dockerfile
index 6a3d7edba0..4784bd73b4 100644
--- a/tools/dockerfile/distribtest/ruby_jessie_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/ruby_jessie_x64/Dockerfile
@@ -29,7 +29,4 @@
 
 FROM debian:jessie
 
-RUN apt-get update
-RUN apt-get install -y git
-RUN apt-get install -y ruby-full
-
+RUN apt-get update && apt-get install -y ruby-full
diff --git a/tools/dockerfile/distribtest/ruby_jessie_x86/Dockerfile b/tools/dockerfile/distribtest/ruby_jessie_x86/Dockerfile
index ca3b731f56..4f649cbc03 100644
--- a/tools/dockerfile/distribtest/ruby_jessie_x86/Dockerfile
+++ b/tools/dockerfile/distribtest/ruby_jessie_x86/Dockerfile
@@ -29,7 +29,4 @@
 
 FROM 32bit/debian:jessie
 
-RUN apt-get update
-RUN apt-get install -y git
-RUN apt-get install -y ruby-full
-
+RUN apt-get update && apt-get install -y ruby-full
diff --git a/tools/dockerfile/distribtest/ruby_opensuse_x64/Dockerfile b/tools/dockerfile/distribtest/ruby_opensuse_x64/Dockerfile
index a9423042ea..a249950998 100644
--- a/tools/dockerfile/distribtest/ruby_opensuse_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/ruby_opensuse_x64/Dockerfile
@@ -29,6 +29,4 @@
 
 FROM opensuse:42.1
 
-RUN zypper --non-interactive install git
 RUN zypper --non-interactive install ruby
-
diff --git a/tools/dockerfile/distribtest/ruby_ubuntu1204_x64/Dockerfile b/tools/dockerfile/distribtest/ruby_ubuntu1204_x64/Dockerfile
index 66f17100cf..95b7702afb 100644
--- a/tools/dockerfile/distribtest/ruby_ubuntu1204_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/ruby_ubuntu1204_x64/Dockerfile
@@ -29,7 +29,4 @@
 
 FROM ubuntu:12.04
 
-RUN apt-get update -y
-RUN apt-get install -y git
-RUN apt-get install -y ruby-full
-
+RUN apt-get update -y && apt-get install -y ruby-full
diff --git a/tools/dockerfile/distribtest/ruby_ubuntu1404_x64/Dockerfile b/tools/dockerfile/distribtest/ruby_ubuntu1404_x64/Dockerfile
index dc533a5fca..66ba01d37e 100644
--- a/tools/dockerfile/distribtest/ruby_ubuntu1404_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/ruby_ubuntu1404_x64/Dockerfile
@@ -29,7 +29,4 @@
 
 FROM ubuntu:14.04
 
-RUN apt-get update -y
-RUN apt-get install -y git
-RUN apt-get install -y ruby-full
-
+RUN apt-get update -y && apt-get install -y ruby-full
diff --git a/tools/dockerfile/distribtest/ruby_ubuntu1504_x64/Dockerfile b/tools/dockerfile/distribtest/ruby_ubuntu1504_x64/Dockerfile
index 7e4f203041..81e7ca1d3c 100644
--- a/tools/dockerfile/distribtest/ruby_ubuntu1504_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/ruby_ubuntu1504_x64/Dockerfile
@@ -29,7 +29,4 @@
 
 FROM ubuntu:15.04
 
-RUN apt-get update -y
-RUN apt-get install -y git
-RUN apt-get install -y ruby-full
-
+RUN apt-get update -y && apt-get install -y ruby-full
diff --git a/tools/dockerfile/distribtest/ruby_ubuntu1510_x64/Dockerfile b/tools/dockerfile/distribtest/ruby_ubuntu1510_x64/Dockerfile
index 43ef63ec8c..37b897f0f5 100644
--- a/tools/dockerfile/distribtest/ruby_ubuntu1510_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/ruby_ubuntu1510_x64/Dockerfile
@@ -29,7 +29,4 @@
 
 FROM ubuntu:15.10
 
-RUN apt-get update -y
-RUN apt-get install -y git
-RUN apt-get install -y ruby-full
-
+RUN apt-get update -y && apt-get install -y ruby-full
diff --git a/tools/dockerfile/distribtest/ruby_ubuntu1604_x64/Dockerfile b/tools/dockerfile/distribtest/ruby_ubuntu1604_x64/Dockerfile
index 3b63976d3c..5c54b8f754 100644
--- a/tools/dockerfile/distribtest/ruby_ubuntu1604_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/ruby_ubuntu1604_x64/Dockerfile
@@ -29,7 +29,4 @@
 
 FROM ubuntu:16.04
 
-RUN apt-get update -y
-RUN apt-get install -y git
-RUN apt-get install -y ruby-full
-
+RUN apt-get update -y && apt-get install -y ruby-full
diff --git a/tools/dockerfile/distribtest/ruby_wheezy_x64/Dockerfile b/tools/dockerfile/distribtest/ruby_wheezy_x64/Dockerfile
index 1ff083d43c..2e6593c230 100644
--- a/tools/dockerfile/distribtest/ruby_wheezy_x64/Dockerfile
+++ b/tools/dockerfile/distribtest/ruby_wheezy_x64/Dockerfile
@@ -29,7 +29,4 @@
 
 FROM debian:wheezy
 
-RUN apt-get update
-RUN apt-get install -y git
-RUN apt-get install -y ruby-full
-
+RUN apt-get update && apt-get install -y ruby-full
diff --git a/tools/jenkins/build_and_run_docker.sh b/tools/jenkins/build_and_run_docker.sh
index b77cd0aebb..92dbbc6f38 100755
--- a/tools/jenkins/build_and_run_docker.sh
+++ b/tools/jenkins/build_and_run_docker.sh
@@ -37,9 +37,6 @@ cd $(dirname $0)/../..
 git_root=$(pwd)
 cd -
 
-# Create a local branch so the child Docker script won't complain
-git branch -f jenkins-docker
-
 # Inputs
 # DOCKERFILE_DIR - Directory in which Dockerfile file is located.
 # DOCKER_RUN_SCRIPT - Script to run under docker (relative to grpc repo root)
diff --git a/tools/jenkins/build_artifacts.sh b/tools/jenkins/build_artifacts.sh
index 9af553ae48..c0acbdfb27 100755
--- a/tools/jenkins/build_artifacts.sh
+++ b/tools/jenkins/build_artifacts.sh
@@ -39,4 +39,8 @@ set -ex -o igncr || set -ex
 curr_platform="$platform"
 unset platform  # variable named 'platform' breaks the windows build
 
-python tools/run_tests/task_runner.py -f artifact $language $curr_platform $architecture
+if [ "$curr_platform" == "linux" ] && [ "$language" == "ruby" ] ; then
+  ./tools/run_tests/build_artifact_ruby.sh
+else
+  python tools/run_tests/task_runner.py -f artifact $language $curr_platform $architecture
+fi
diff --git a/tools/jenkins/docker_run.sh b/tools/jenkins/docker_run.sh
index 49553aae2f..519dc5cade 100755
--- a/tools/jenkins/docker_run.sh
+++ b/tools/jenkins/docker_run.sh
@@ -31,18 +31,24 @@
 # This script is invoked by build_docker_* inside a docker
 # container. You should never need to call this script on your own.
 
-set -e
+set -ex
 
-mkdir -p /var/local/git
-git clone --recursive "$EXTERNAL_GIT_ROOT" /var/local/git/grpc
+if [ "$RELATIVE_COPY_PATH" == "" ]
+then
+  mkdir -p /var/local/git
+  git clone --recursive "$EXTERNAL_GIT_ROOT" /var/local/git/grpc
+else
+  mkdir -p "/var/local/git/grpc/$RELATIVE_COPY_PATH"
+  cp -r "$EXTERNAL_GIT_ROOT/$RELATIVE_COPY_PATH"/* "/var/local/git/grpc/$RELATIVE_COPY_PATH"
+fi
 
 if [ -x "$(command -v rvm)" ]
 then
   rvm use ruby-2.1
 fi
 
-cd /var/local/git/grpc
-
 nvm use 4 || true
 
+cd /var/local/git/grpc
+
 $RUN_COMMAND
diff --git a/tools/jenkins/docker_run_tests.sh b/tools/jenkins/docker_run_tests.sh
index 26e5585d2d..12874386a3 100755
--- a/tools/jenkins/docker_run_tests.sh
+++ b/tools/jenkins/docker_run_tests.sh
@@ -43,8 +43,6 @@ chown `whoami` $XDG_CACHE_HOME
 mkdir -p /var/local/git
 git clone --recursive /var/local/jenkins/grpc /var/local/git/grpc
 
-nvm use 0.12 || true
-
 if [ -x "$(command -v rvm)" ]
 then
   rvm use ruby-2.1
diff --git a/tools/run_tests/build_artifact_python.sh b/tools/run_tests/build_artifact_python.sh
index 48cf390f69..835fad83e1 100755
--- a/tools/run_tests/build_artifact_python.sh
+++ b/tools/run_tests/build_artifact_python.sh
@@ -39,11 +39,13 @@ then
   pip install -rrequirements.txt
 fi
 
-GRPC_PYTHON_BUILD_WITH_CYTHON=1 ${SETARCH_CMD} python setup.py \
-    bdist_wheel \
-    sdist \
+GRPC_PYTHON_USE_CUSTOM_BDIST=0  \
+GRPC_PYTHON_BUILD_WITH_CYTHON=1 \
+${SETARCH_CMD} python setup.py  \
+    bdist_wheel                 \
+    sdist                       \
     bdist_egg_grpc_custom
 
 mkdir -p artifacts
 
-cp -r dist/* artifacts
\ No newline at end of file
+cp -r dist/* artifacts
diff --git a/tools/run_tests/build_artifact_ruby.sh b/tools/run_tests/build_artifact_ruby.sh
index 482d128be3..2d97b4068b 100755
--- a/tools/run_tests/build_artifact_ruby.sh
+++ b/tools/run_tests/build_artifact_ruby.sh
@@ -27,16 +27,40 @@
 # 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.
-
 set -ex
 
+SYSTEM=`uname | cut -f 1 -d_`
+
 cd $(dirname $0)/../..
+set +ex
+[[ -s /etc/profile.d/rvm.sh ]] && . /etc/profile.d/rvm.sh
+[[ -s "$HOME/.rvm/scripts/rvm" ]] && source "$HOME/.rvm/scripts/rvm"
+set -ex
+
+if [ "$SYSTEM" == "MSYS" ] ; then
+  SYSTEM=MINGW32
+fi
+if [ "$SYSTEM" == "MINGW64" ] ; then
+  SYSTEM=MINGW32
+fi
 
-${SETARCH_CMD} bundle install
+if [ "$SYSTEM" == "MINGW32" ] ; then
+  echo "Need Linux to build the Windows ruby gem."
+  exit 1
+fi
 
-${SETARCH_CMD} rake native gem
+set +ex
+rvm use default
+gem install bundler --update
+bundle install
+set -ex
+
+rake gem:native
+
+if [ "$SYSTEM" == "Darwin" ] ; then
+  rm `ls pkg/*.gem | grep -v darwin`
+fi
 
 mkdir -p artifacts
 
 cp pkg/*.gem artifacts
-
diff --git a/tools/run_tests/build_node.sh b/tools/run_tests/build_node.sh
index 8f2ab4413a..9c4af07185 100755
--- a/tools/run_tests/build_node.sh
+++ b/tools/run_tests/build_node.sh
@@ -29,8 +29,12 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+NODE_VERSION=$1
+source ~/.nvm/nvm.sh
 set -ex
 
+nvm use $NODE_VERSION
+
 CONFIG=${CONFIG:-opt}
 
 # change to grpc repo root
diff --git a/tools/run_tests/build_package_python.sh b/tools/run_tests/build_package_python.sh
new file mode 100755
index 0000000000..2511a6ae46
--- /dev/null
+++ b/tools/run_tests/build_package_python.sh
@@ -0,0 +1,43 @@
+#!/bin/bash
+# Copyright 2016, 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.
+
+set -ex
+
+cd $(dirname $0)/../..
+
+mkdir -p artifacts/
+
+# All the python packages have been built in the artifact phase already
+# and we only collect them here to deliver them to the distribtest phase.
+cp -r $EXTERNAL_GIT_ROOT/architecture={x86,x64},language=python,platform={windows,linux,macos}/artifacts/* artifacts/ || true
+
+# TODO: all the artifact builder configurations generate a grpcio-VERSION.tar.gz
+# source distribution package, and only one of them will end up
+# in the artifacts/ directory. They should be all equivalent though.
diff --git a/tools/run_tests/build_package_ruby.sh b/tools/run_tests/build_package_ruby.sh
new file mode 100755
index 0000000000..1a5b94348d
--- /dev/null
+++ b/tools/run_tests/build_package_ruby.sh
@@ -0,0 +1,43 @@
+#!/bin/bash
+# Copyright 2016, 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.
+
+set -ex
+
+cd $(dirname $0)/../..
+
+mkdir -p artifacts/
+
+# All the ruby packages have been built in the artifact phase already
+# and we only collect them here to deliver them to the distribtest phase.
+cp -r $EXTERNAL_GIT_ROOT/architecture={x86,x64},language=ruby,platform={windows,linux,macos}/artifacts/* artifacts/ || true
+
+# TODO: all the artifact builder configurations generate a grpc-VERSION.gem
+# source distribution package, and only one of them will end up
+# in the artifacts/ directory. They should be all equivalent though.
diff --git a/tools/run_tests/distribtest_targets.py b/tools/run_tests/distribtest_targets.py
index e9a80d2cf4..fc7dd17145 100644
--- a/tools/run_tests/distribtest_targets.py
+++ b/tools/run_tests/distribtest_targets.py
@@ -38,6 +38,7 @@ def create_docker_jobspec(name, dockerfile_dir, shell_command, environ={},
   """Creates jobspec for a task running under docker."""
   environ = environ.copy()
   environ['RUN_COMMAND'] = shell_command
+  environ['RELATIVE_COPY_PATH'] = 'test/distrib'
 
   docker_args=[]
   for k,v in environ.iteritems():
@@ -54,28 +55,49 @@ def create_docker_jobspec(name, dockerfile_dir, shell_command, environ={},
   return jobspec
 
 
+def create_jobspec(name, cmdline, environ=None, shell=False,
+                   flake_retries=0, timeout_retries=0):
+  """Creates jobspec."""
+  jobspec = jobset.JobSpec(
+          cmdline=cmdline,
+          environ=environ,
+          shortname='distribtest.%s' % (name),
+          timeout_seconds=10*60,
+          flake_retries=flake_retries,
+          timeout_retries=timeout_retries,
+          shell=shell)
+  return jobspec
+
+
 class CSharpDistribTest(object):
   """Tests C# NuGet package"""
 
-  def __init__(self, platform, arch, docker_suffix):
-    self.name = 'csharp_nuget_%s_%s_%s' % (platform, arch, docker_suffix)
+  def __init__(self, platform, arch, docker_suffix=None):
+    self.name = 'csharp_nuget_%s_%s' % (platform, arch)
     self.platform = platform
     self.arch = arch
     self.docker_suffix = docker_suffix
-    self.labels = ['distribtest', 'csharp', platform, arch, docker_suffix]
+    self.labels = ['distribtest', 'csharp', platform, arch]
+    if docker_suffix:
+      self.name += '_%s' % docker_suffix
+      self.labels.append(docker_suffix)
 
   def pre_build_jobspecs(self):
     return []
 
   def build_jobspec(self):
-    if not self.platform == 'linux':
-      raise Exception("Not supported yet.")
-
-    return create_docker_jobspec(self.name,
+    if self.platform == 'linux':
+      return create_docker_jobspec(self.name,
           'tools/dockerfile/distribtest/csharp_%s_%s' % (
               self.docker_suffix,
               self.arch),
           'test/distrib/csharp/run_distrib_test.sh')
+    elif self.platform == 'macos':
+      return create_jobspec(self.name,
+          ['test/distrib/csharp/run_distrib_test.sh'],
+          environ={'EXTERNAL_GIT_ROOT': '../../..'})
+    else:
+      raise Exception("Not supported yet.")
 
   def __str__(self):
     return self.name
@@ -104,8 +126,7 @@ class NodeDistribTest(object):
                                  'tools/dockerfile/distribtest/node_%s_%s' % (
                                      self.docker_suffix,
                                      self.arch),
-                                 # bash -l needed to make nvm available
-                                 'bash -l test/distrib/node/run_distrib_test.sh %s' % (
+                                 'test/distrib/node/run_distrib_test.sh %s' % (
                                      self.node_version))
     def __str__(self):
       return self.name
@@ -175,6 +196,7 @@ def targets():
           CSharpDistribTest('linux', 'x64', 'ubuntu1504'),
           CSharpDistribTest('linux', 'x64', 'ubuntu1510'),
           CSharpDistribTest('linux', 'x64', 'ubuntu1604'),
+          CSharpDistribTest('macos', 'x86'),
           PythonDistribTest('linux', 'x64', 'wheezy'),
           PythonDistribTest('linux', 'x64', 'jessie'),
           PythonDistribTest('linux', 'x86', 'jessie'),
diff --git a/tools/run_tests/interop_html_report.template b/tools/run_tests/interop_html_report.template
index 114a508c31..46cce426b7 100644
--- a/tools/run_tests/interop_html_report.template
+++ b/tools/run_tests/interop_html_report.template
@@ -64,17 +64,8 @@
   % endif
 </%def>
 
-% if num_failures > 1:
-  <p><h2><font color="red">${num_failures} tests failed!</font></h2></p>
-% elif num_failures:
-  <p><h2><font color="red">${num_failures} test failed!</font></h2></p>
-% else:
-  <p><h2><font color="green">All tests passed!</font></h2></p>
-% endif
-
-% if cloud_to_prod:
+<%def name="display_cloud_to_prod_result(prod_server)">
   ## Each column header is the client language.
-  <h2>Cloud to Prod</h2>
   <table style="width:100%" border="1">
   <tr bgcolor="#00BFFF">
   <th>Client languages &#9658;<br/>Test Cases &#9660;</th>
@@ -87,15 +78,32 @@
     % for client_lang in client_langs:
       <% 
         if test_case in auth_test_cases:
-          shortname = 'cloud_to_prod_auth:%s:%s' % (client_lang, test_case)
+          shortname = 'cloud_to_prod_auth:%s:%s:%s' % (
+              prod_server, client_lang, test_case)
         else:
-          shortname = 'cloud_to_prod:%s:%s' % (client_lang, test_case)
+          shortname = 'cloud_to_prod:%s:%s:%s' % (
+              prod_server, client_lang, test_case)
       %>
       ${fill_one_test_result(shortname, resultset)}
     % endfor
     </tr> 
   % endfor
   </table>
+</%def>
+
+% if num_failures > 1:
+  <p><h2><font color="red">${num_failures} tests failed!</font></h2></p>
+% elif num_failures:
+  <p><h2><font color="red">${num_failures} test failed!</font></h2></p>
+% else:
+  <p><h2><font color="green">All tests passed!</font></h2></p>
+% endif
+
+% if cloud_to_prod:
+  % for prod_server in prod_servers:
+    <h2>Cloud to ${prod_server}</h2>
+    ${display_cloud_to_prod_result(prod_server)}
+  % endfor
 % endif
 
 % if http2_interop:
@@ -108,7 +116,9 @@
     <th>${server_lang}</th>
   % endfor
   % if cloud_to_prod:
-    <th>prod</th>
+    % for prod_server in prod_servers:
+      <th>${prod_server}</th>
+    % endfor
   % endif
   </tr>
   % for test_case in http2_cases:
@@ -122,8 +132,10 @@
       ${fill_one_http2_test_result(shortname, resultset)}
     % endfor
     % if cloud_to_prod:
-      <% shortname = 'cloud_to_prod:http2:%s' % test_case %>
-      ${fill_one_http2_test_result(shortname, resultset)}
+      % for prod_server in prod_servers:
+        <% shortname = 'cloud_to_prod:%s:http2:%s' % (prod_server, test_case) %>
+        ${fill_one_http2_test_result(shortname, resultset)}
+      % endfor
     % endif
     </tr>
   % endfor
diff --git a/tools/run_tests/package_targets.py b/tools/run_tests/package_targets.py
index 997bc57cc5..4ca8279f1b 100644
--- a/tools/run_tests/package_targets.py
+++ b/tools/run_tests/package_targets.py
@@ -68,11 +68,11 @@ def create_jobspec(name, cmdline, environ=None, cwd=None, shell=False,
   return jobspec
 
 
-class CSharpNugetTarget:
+class CSharpPackage:
   """Builds C# nuget packages."""
 
   def __init__(self):
-    self.name = 'csharp_nuget'
+    self.name = 'csharp_package'
     self.labels = ['package', 'csharp', 'windows']
 
   def pre_build_jobspecs(self):
@@ -87,11 +87,12 @@ class CSharpNugetTarget:
   def __str__(self):
     return self.name
 
-class NodeNpmBinaryTarget:
-  """Builds Node NPM package and collects binaries"""
+
+class NodePackage:
+  """Builds Node NPM package and collects precompiled binaries"""
 
   def __init__(self):
-    self.name = 'node_npm_binary'
+    self.name = 'node_package'
     self.labels = ['package', 'node', 'linux']
 
   def pre_build_jobspecs(self):
@@ -103,6 +104,44 @@ class NodeNpmBinaryTarget:
         'tools/dockerfile/grpc_artifact_linux_x64',
         'tools/run_tests/build_package_node.sh')
 
+
+class RubyPackage:
+  """Collects ruby gems created in the artifact phase"""
+
+  def __init__(self):
+    self.name = 'ruby_package'
+    self.labels = ['package', 'ruby', 'linux']
+
+  def pre_build_jobspecs(self):
+    return []
+
+  def build_jobspec(self):
+    return create_docker_jobspec(
+        self.name,
+        'tools/dockerfile/grpc_artifact_linux_x64',
+        'tools/run_tests/build_package_ruby.sh')
+
+
+class PythonPackage:
+  """Collects python eggs and wheels created in the artifact phase"""
+
+  def __init__(self):
+    self.name = 'python_package'
+    self.labels = ['package', 'python', 'linux']
+
+  def pre_build_jobspecs(self):
+    return []
+
+  def build_jobspec(self):
+    return create_docker_jobspec(
+        self.name,
+        'tools/dockerfile/grpc_artifact_linux_x64',
+        'tools/run_tests/build_package_python.sh')
+
+
 def targets():
   """Gets list of supported targets"""
-  return [CSharpNugetTarget(), NodeNpmBinaryTarget()]
+  return [CSharpPackage(),
+          NodePackage(),
+          RubyPackage(),
+          PythonPackage()]
diff --git a/tools/run_tests/pre_build_node.sh b/tools/run_tests/pre_build_node.sh
index 28ce354f27..11f46d60fc 100755
--- a/tools/run_tests/pre_build_node.sh
+++ b/tools/run_tests/pre_build_node.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -29,8 +29,12 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+NODE_VERSION=$1
+source ~/.nvm/nvm.sh
 set -ex
 
+nvm use $NODE_VERSION
+
 export GRPC_CONFIG=${CONFIG:-opt}
 
 # Expire cache after 1 week
diff --git a/tools/run_tests/report_utils.py b/tools/run_tests/report_utils.py
index 35f2069bee..0032a98523 100644
--- a/tools/run_tests/report_utils.py
+++ b/tools/run_tests/report_utils.py
@@ -1,4 +1,4 @@
-# Copyright 2015, Google Inc.
+# Copyright 2015-2016, Google Inc.
 # All rights reserved.
 #
 # Redistribution and use in source and binary forms, with or without
@@ -77,7 +77,7 @@ def render_junit_xml_report(resultset, xml_report):
 
 def render_interop_html_report(
   client_langs, server_langs, test_cases, auth_test_cases, http2_cases, 
-  resultset, num_failures, cloud_to_prod, http2_interop):
+  resultset, num_failures, cloud_to_prod, prod_servers, http2_interop):
   """Generate HTML report for interop tests."""
   template_file = 'tools/run_tests/interop_html_report.template'
   try:
@@ -94,6 +94,7 @@ def render_interop_html_report(
   sorted_http2_cases = sorted(http2_cases)
   sorted_client_langs = sorted(client_langs)
   sorted_server_langs = sorted(server_langs)
+  sorted_prod_servers = sorted(prod_servers)
 
   args = {'client_langs': sorted_client_langs, 
           'server_langs': sorted_server_langs,
@@ -103,6 +104,7 @@ def render_interop_html_report(
           'resultset': resultset,
           'num_failures': num_failures,
           'cloud_to_prod': cloud_to_prod,
+          'prod_servers': sorted_prod_servers,
           'http2_interop': http2_interop}
 
   html_report_out_dir = 'reports' 
diff --git a/tools/run_tests/run_interop_tests.py b/tools/run_tests/run_interop_tests.py
index fbc3b3cdf6..4a670e0c9d 100755
--- a/tools/run_tests/run_interop_tests.py
+++ b/tools/run_tests/run_interop_tests.py
@@ -422,12 +422,13 @@ def _job_kill_handler(job):
     time.sleep(2)
 
 
-def cloud_to_prod_jobspec(language, test_case, docker_image=None, auth=False):
+def cloud_to_prod_jobspec(language, test_case, server_host_name, 
+                          server_host_detail, docker_image=None, auth=False):
   """Creates jobspec for cloud-to-prod interop test"""
   container_name = None
   cmdargs = [
-      '--server_host_override=grpc-test.sandbox.googleapis.com',
-      '--server_host=grpc-test.sandbox.googleapis.com',
+      '--server_host=%s' % server_host_detail[0],
+      '--server_host_override=%s' % server_host_detail[1],
       '--server_port=443',
       '--use_tls=true',
       '--test_case=%s' % test_case]
@@ -440,7 +441,8 @@ def cloud_to_prod_jobspec(language, test_case, docker_image=None, auth=False):
   cwd = language.client_cwd
 
   if docker_image:
-    container_name = dockerjob.random_name('interop_client_%s' % language.safename)
+    container_name = dockerjob.random_name('interop_client_%s' % 
+                                           language.safename)
     cmdline = docker_run_cmdline(cmdline,
                                  image=docker_image,
                                  cwd=cwd,
@@ -455,7 +457,8 @@ def cloud_to_prod_jobspec(language, test_case, docker_image=None, auth=False):
           cmdline=cmdline,
           cwd=cwd,
           environ=environ,
-          shortname='%s:%s:%s' % (suite_name, language, test_case),
+          shortname='%s:%s:%s:%s' % (suite_name, server_host_name, language, 
+                                     test_case),
           timeout_seconds=90,
           flake_retries=5 if args.allow_flakes else 0,
           timeout_retries=2 if args.allow_flakes else 0,
@@ -491,7 +494,7 @@ def cloud_to_cloud_jobspec(language, test_case, server_name, server_host,
           cwd=cwd,
           environ=environ,
           shortname='cloud_to_cloud:%s:%s_server:%s' % (language, server_name,
-                                                 test_case),
+                                                        test_case),
           timeout_seconds=90,
           flake_retries=5 if args.allow_flakes else 0,
           timeout_retries=2 if args.allow_flakes else 0,
@@ -572,6 +575,21 @@ def aggregate_http2_results(stdout):
     'percent': 1.0 * passed / (passed + failed)
   }
 
+# A dictionary of prod servers to test. 
+# Format: server_name: (server_host, server_host_override, errors_allowed)
+# TODO(adelez): implement logic for errors_allowed where if the indicated tests
+# fail, they don't impact the overall test result.
+prod_servers = {
+    'default': ('grpc-test.sandbox.googleapis.com', 
+                'grpc-test.sandbox.googleapis.com', False),
+    'gateway_v2': ('grpc-test2.sandbox.googleapis.com', 
+                   'grpc-test2.sandbox.googleapis.com', True),
+    'cloud_gateway': ('216.239.32.255', 'grpc-test.sandbox.googleapis.com', 
+                      False),
+    'cloud_gateway_v2': ('216.239.32.255', 'grpc-test2.sandbox.googleapis.com', 
+                         True)
+}
+
 argp = argparse.ArgumentParser(description='Run interop tests.')
 argp.add_argument('-l', '--language',
                   choices=['all'] + sorted(_LANGUAGES),
@@ -589,6 +607,12 @@ argp.add_argument('--cloud_to_prod_auth',
                   action='store_const',
                   const=True,
                   help='Run cloud_to_prod_auth tests.')
+argp.add_argument('--prod_servers',
+                  choices=prod_servers.keys(),
+                  default=['default'],
+                  nargs='+',
+                  help=('The servers to run cloud_to_prod and '
+                        'cloud_to_prod_auth tests against.'))
 argp.add_argument('-s', '--server',
                   choices=['all'] + sorted(_SERVERS),
                   action='append',
@@ -688,32 +712,37 @@ try:
     server_jobs[lang] = job
     server_addresses[lang] = ('localhost', job.mapped_port(_DEFAULT_SERVER_PORT))
 
-
   jobs = []
   if args.cloud_to_prod:
-    for language in languages:
-      for test_case in _TEST_CASES:
-        if not test_case in language.unimplemented_test_cases():
-          if not test_case in _SKIP_ADVANCED + _SKIP_COMPRESSION:
-            test_job = cloud_to_prod_jobspec(language, test_case,
-                                             docker_image=docker_images.get(str(language)))
-            jobs.append(test_job)
-
-    if args.http2_interop:
-      for test_case in _HTTP2_TEST_CASES:
-        test_job = cloud_to_prod_jobspec(http2Interop, test_case,
-                                         docker_image=docker_images.get(str(http2Interop)))
-        jobs.append(test_job)
-
+    for server_host_name in args.prod_servers:
+      for language in languages:
+        for test_case in _TEST_CASES:
+          if not test_case in language.unimplemented_test_cases():
+            if not test_case in _SKIP_ADVANCED + _SKIP_COMPRESSION:
+              test_job = cloud_to_prod_jobspec(
+                  language, test_case, server_host_name, 
+                  prod_servers[server_host_name],
+                  docker_image=docker_images.get(str(language)))
+              jobs.append(test_job)
+
+      if args.http2_interop:
+        for test_case in _HTTP2_TEST_CASES:
+          test_job = cloud_to_prod_jobspec(
+              http2Interop, test_case, server_host_name, 
+              prod_servers[server_host_name],
+              docker_image=docker_images.get(str(http2Interop)))
+          jobs.append(test_job)
 
   if args.cloud_to_prod_auth:
-    for language in languages:
-      for test_case in _AUTH_TEST_CASES:
-        if not test_case in language.unimplemented_test_cases():
-          test_job = cloud_to_prod_jobspec(language, test_case,
-                                           docker_image=docker_images.get(str(language)),
-                                           auth=True)
-          jobs.append(test_job)
+    for server_host_name in args.prod_servers:
+      for language in languages:
+        for test_case in _AUTH_TEST_CASES:
+          if not test_case in language.unimplemented_test_cases():
+            test_job = cloud_to_prod_jobspec(
+                language, test_case, server_host_name, 
+                prod_servers[server_host_name],
+                docker_image=docker_images.get(str(language)), auth=True)
+            jobs.append(test_job)
 
   for server in args.override_server:
     server_name = server[0]
@@ -773,7 +802,8 @@ try:
   report_utils.render_interop_html_report(
       set([str(l) for l in languages]), servers, _TEST_CASES, _AUTH_TEST_CASES,
       _HTTP2_TEST_CASES, resultset, num_failures,
-      args.cloud_to_prod_auth or args.cloud_to_prod, args.http2_interop)
+      args.cloud_to_prod_auth or args.cloud_to_prod, args.prod_servers, 
+      args.http2_interop)
 
 finally:
   # Check if servers are still running.
diff --git a/tools/run_tests/run_node.sh b/tools/run_tests/run_node.sh
index f93c9c30cb..40f61d77cc 100755
--- a/tools/run_tests/run_node.sh
+++ b/tools/run_tests/run_node.sh
@@ -28,8 +28,12 @@
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+NODE_VERSION=$1
+source ~/.nvm/nvm.sh
 set -ex
 
+nvm use $NODE_VERSION
+
 CONFIG=${CONFIG:-opt}
 
 # change to grpc repo root
diff --git a/tools/run_tests/run_tests.py b/tools/run_tests/run_tests.py
index 9e7b97c6a2..6dfdc705be 100755
--- a/tools/run_tests/run_tests.py
+++ b/tools/run_tests/run_tests.py
@@ -194,13 +194,17 @@ class CLanguage(object):
 
 class NodeLanguage(object):
 
+  def __init__(self):
+    self.node_version = '0.12'
+
   def test_specs(self, config, args):
-    return [config.job_spec(['tools/run_tests/run_node.sh'], None,
+    return [config.job_spec(['tools/run_tests/run_node.sh', self.node_version],
+                            None,
                             environ=_FORCE_ENVIRON_FOR_WRAPPERS)]
 
   def pre_build_steps(self):
     # Default to 1 week cache expiration
-    return [['tools/run_tests/pre_build_node.sh']]
+    return [['tools/run_tests/pre_build_node.sh', self.node_version]]
 
   def make_targets(self, test_regex):
     return []
@@ -209,7 +213,7 @@ class NodeLanguage(object):
     return []
 
   def build_steps(self):
-    return [['tools/run_tests/build_node.sh']]
+    return [['tools/run_tests/build_node.sh', self.node_version]]
 
   def post_tests_steps(self):
     return []