diff --git a/BUILD.bazel b/BUILD.bazel
index 0463f4cc2..46032144a 100644
--- a/BUILD.bazel
+++ b/BUILD.bazel
@@ -545,6 +545,7 @@ cc_binary(
     visibility = ["//java:__subpackages__"],
     deps = [
         ":gcs_server_lib",
+        ":stats_lib",
         "@com_github_gflags_gflags//:gflags",
     ],
 )
diff --git a/bazel/ray_deps_setup.bzl b/bazel/ray_deps_setup.bzl
index bd4111d21..d40f217f1 100644
--- a/bazel/ray_deps_setup.bzl
+++ b/bazel/ray_deps_setup.bzl
@@ -204,6 +204,7 @@ def ray_deps_setup():
         sha256 = "6592e07672e7f7980687f6c1abda81974d8d379e273fea3b54b6c4d855489b9d",
         patches = [
             "//thirdparty/patches:opencensus-cpp-harvest-interval.patch",
+            "//thirdparty/patches:opencensus-cpp-shutdown-api.patch",
         ]
     )
 
diff --git a/python/ray/node.py b/python/ray/node.py
index 768e901ee..8fce783ac 100644
--- a/python/ray/node.py
+++ b/python/ray/node.py
@@ -635,7 +635,8 @@ class Node:
             redis_password=self._ray_params.redis_password,
             config=self._config,
             fate_share=self.kernel_fate_share,
-            gcs_server_port=self._ray_params.gcs_server_port)
+            gcs_server_port=self._ray_params.gcs_server_port,
+            metrics_agent_port=self._ray_params.metrics_agent_port)
         assert (
             ray_constants.PROCESS_TYPE_GCS_SERVER not in self.all_processes)
         self.all_processes[ray_constants.PROCESS_TYPE_GCS_SERVER] = [
diff --git a/python/ray/services.py b/python/ray/services.py
index 57aa5fd51..0c90fe834 100644
--- a/python/ray/services.py
+++ b/python/ray/services.py
@@ -1203,7 +1203,8 @@ def start_gcs_server(redis_address,
                      redis_password=None,
                      config=None,
                      fate_share=None,
-                     gcs_server_port=None):
+                     gcs_server_port=None,
+                     metrics_agent_port=None):
     """Start a gcs server.
     Args:
         redis_address (str): The address that the Redis server is listening on.
@@ -1215,6 +1216,7 @@ def start_gcs_server(redis_address,
         config (dict|None): Optional configuration that will
             override defaults in RayConfig.
         gcs_server_port (int): Port number of the gcs server.
+        metrics_agent_port(int): The port where metrics agent is bound to.
     Returns:
         ProcessInfo for the process that was started.
     """
@@ -1230,6 +1232,7 @@ def start_gcs_server(redis_address,
         "--redis_port={}".format(gcs_port),
         "--config_list={}".format(config_str),
         "--gcs_server_port={}".format(gcs_server_port),
+        "--metrics-agent-port={}".format(metrics_agent_port),
     ]
     if redis_password:
         command += ["--redis_password={}".format(redis_password)]
diff --git a/src/ray/core_worker/transport/direct_actor_transport.h b/src/ray/core_worker/transport/direct_actor_transport.h
index e3d4dae3b..1436e988b 100644
--- a/src/ray/core_worker/transport/direct_actor_transport.h
+++ b/src/ray/core_worker/transport/direct_actor_transport.h
@@ -220,7 +220,7 @@ class CoreWorkerDirectActorTaskSubmitter
   /// Factory for producing new core worker clients.
   rpc::ClientFactoryFn client_factory_;
 
-  /// Mutex to proect the various maps below.
+  /// Mutex to protect the various maps below.
   mutable absl::Mutex mu_;
 
   absl::flat_hash_map<ActorID, ClientQueue> client_queues_ GUARDED_BY(mu_);
diff --git a/src/ray/gcs/gcs_server/gcs_server_main.cc b/src/ray/gcs/gcs_server/gcs_server_main.cc
index 167f04b1f..fd9033453 100644
--- a/src/ray/gcs/gcs_server/gcs_server_main.cc
+++ b/src/ray/gcs/gcs_server/gcs_server_main.cc
@@ -17,11 +17,13 @@
 #include "gflags/gflags.h"
 #include "ray/common/ray_config.h"
 #include "ray/gcs/gcs_server/gcs_server.h"
+#include "ray/stats/stats.h"
 #include "ray/util/util.h"
 
 DEFINE_string(redis_address, "", "The ip address of redis.");
 DEFINE_int32(redis_port, -1, "The port of redis.");
 DEFINE_int32(gcs_server_port, -1, "The port of gcs server.");
+DEFINE_int32(metrics_agent_port, -1, "The port of metrics agent.");
 DEFINE_string(config_list, "", "The config list of raylet.");
 DEFINE_string(redis_password, "", "The password of redis.");
 DEFINE_bool(retry_redis, false, "Whether we retry to connect to the redis.");
@@ -36,6 +38,7 @@ int main(int argc, char *argv[]) {
   const std::string redis_address = FLAGS_redis_address;
   const int redis_port = static_cast<int>(FLAGS_redis_port);
   const int gcs_server_port = static_cast<int>(FLAGS_gcs_server_port);
+  const int metrics_agent_port = static_cast<int>(FLAGS_metrics_agent_port);
   const std::string config_list = FLAGS_config_list;
   const std::string redis_password = FLAGS_redis_password;
   const bool retry_redis = FLAGS_retry_redis;
@@ -54,6 +57,9 @@ int main(int argc, char *argv[]) {
   }
 
   RayConfig::instance().initialize(config_map);
+  const ray::stats::TagsType global_tags = {{ray::stats::JobNameKey, "gcs_server"},
+                                            {ray::stats::VersionKey, "0.9.0.dev0"}};
+  ray::stats::Init(global_tags, metrics_agent_port);
 
   boost::asio::io_service main_service;
 
@@ -74,6 +80,7 @@ int main(int argc, char *argv[]) {
                                               int signal_number) {
     RAY_LOG(INFO) << "GCS server received SIGTERM, shutting down...";
     gcs_server.Stop();
+    ray::stats::Shutdown();
     main_service.stop();
   };
   boost::asio::signal_set signals(main_service);
diff --git a/src/ray/raylet/main.cc b/src/ray/raylet/main.cc
index 0db0e25be..c07800712 100644
--- a/src/ray/raylet/main.cc
+++ b/src/ray/raylet/main.cc
@@ -229,7 +229,7 @@ int main(int argc, char *argv[]) {
       {ray::stats::JobNameKey, "raylet"},
       {ray::stats::VersionKey, "0.9.0.dev0"},
       {ray::stats::NodeAddressKey, node_ip_address}};
-  ray::stats::Init(global_tags, metrics_agent_port, main_service);
+  ray::stats::Init(global_tags, metrics_agent_port);
 
   // Destroy the Raylet on a SIGTERM. The pointer to main_service is
   // guaranteed to be valid since this function will run the event loop
@@ -240,6 +240,7 @@ int main(int argc, char *argv[]) {
     RAY_LOG(INFO) << "Raylet received SIGTERM, shutting down...";
     server->Stop();
     gcs_client->Disconnect();
+    ray::stats::Shutdown();
     main_service.stop();
     remove(raylet_socket_name.c_str());
   };
diff --git a/src/ray/raylet/node_manager.cc b/src/ray/raylet/node_manager.cc
index 061529bb0..6cd75b6f6 100644
--- a/src/ray/raylet/node_manager.cc
+++ b/src/ray/raylet/node_manager.cc
@@ -3583,9 +3583,6 @@ void NodeManager::FlushObjectsToFree() {
 void NodeManager::HandleGetNodeStats(const rpc::GetNodeStatsRequest &node_stats_request,
                                      rpc::GetNodeStatsReply *reply,
                                      rpc::SendReplyCallback send_reply_callback) {
-  // NOTE(sang): Currently reporting only infeasible/ready ActorCreationTask
-  // because Ray dashboard only renders actorCreationTask as of Feb 3 2020.
-  // TODO(sang): Support dashboard for non-ActorCreationTask.
   for (const auto task : local_queues_.GetTasks(TaskState::INFEASIBLE)) {
     if (task.GetTaskSpecification().IsActorCreationTask()) {
       auto infeasible_task = reply->add_infeasible_tasks();
@@ -3594,8 +3591,6 @@ void NodeManager::HandleGetNodeStats(const rpc::GetNodeStatsRequest &node_stats_
   }
   // Report tasks that are not scheduled because
   // resources are occupied by other actors/tasks.
-  // NOTE(sang): This solution is a workaround. It can be replaced by creating a new state
-  // like PENDING_UNTIL_RESOURCE_AVAILABLE.
   for (const auto task : local_queues_.GetTasks(TaskState::READY)) {
     if (task.GetTaskSpecification().IsActorCreationTask()) {
       auto ready_task = reply->add_ready_tasks();
diff --git a/src/ray/stats/metric.cc b/src/ray/stats/metric.cc
index 53fd22ed6..472b8209d 100644
--- a/src/ray/stats/metric.cc
+++ b/src/ray/stats/metric.cc
@@ -67,6 +67,10 @@ const absl::Duration &StatsConfig::GetHarvestInterval() const {
   return harvest_interval_;
 }
 
+void StatsConfig::SetIsInitialized(bool initialized) { is_initialized_ = initialized; }
+
+bool StatsConfig::IsInitialized() const { return is_initialized_; }
+
 void Metric::Record(double value, const TagsType &tags) {
   if (StatsConfig::instance().IsStatsDisabled()) {
     return;
diff --git a/src/ray/stats/metric.h b/src/ray/stats/metric.h
index 876526d48..b20482c03 100644
--- a/src/ray/stats/metric.h
+++ b/src/ray/stats/metric.h
@@ -29,30 +29,42 @@ namespace stats {
 /// Include tag_defs.h to define tag items
 #include "ray/stats/tag_defs.h"
 
+/// StatsConfig per process.
+/// Note that this is not thread-safe. Don't modify its internal values
+/// outside stats::Init() or stats::Shutdown() method.
 class StatsConfig final {
  public:
   static StatsConfig &instance();
 
-  /// Set the global tags that will be appended to all metrics in this process.
-  void SetGlobalTags(const TagsType &global_tags);
-
   /// Get the current global tags.
   const TagsType &GetGlobalTags() const;
 
-  /// Set if the stats are enabled in this process.
-  void SetIsDisableStats(bool disable_stats);
-
   /// Get whether or not stats are enabled.
   bool IsStatsDisabled() const;
 
-  void SetReportInterval(const absl::Duration interval);
-
   const absl::Duration &GetReportInterval() const;
 
-  void SetHarvestInterval(const absl::Duration interval);
-
   const absl::Duration &GetHarvestInterval() const;
 
+  bool IsInitialized() const;
+
+  ///
+  /// Functions that should be used only inside stats::Init()
+  /// NOTE: StatsConfig is not thread-safe. If you use these functions
+  /// in multi threaded environment, it can cause problems.
+  ///
+
+  /// Set the stats have been initialized.
+  void SetIsInitialized(bool initialized);
+  /// Set the interval where metrics are harvetsed.
+  void SetHarvestInterval(const absl::Duration interval);
+  /// Set the interval where metrics are reported to data sinks.
+  void SetReportInterval(const absl::Duration interval);
+  /// Set if the stats are enabled in this process.
+  void SetIsDisableStats(bool disable_stats);
+  /// Set the global tags that will be appended to all metrics in this process.
+  void SetGlobalTags(const TagsType &global_tags);
+
  private:
   StatsConfig() = default;
   ~StatsConfig() = default;
@@ -70,6 +82,8 @@ class StatsConfig final {
   // report interval. So harvest interval is suggusted to be half of report
   // interval.
   absl::Duration harvest_interval_ = absl::Seconds(5);
+  // Whether or not if the stats has been initialized.
+  bool is_initialized_ = false;
 };
 
 /// A thin wrapper that wraps the `opencensus::tag::measure` for using it simply.
diff --git a/src/ray/stats/metric_defs.h b/src/ray/stats/metric_defs.h
index 4c84e8fbb..0d5021827 100644
--- a/src/ray/stats/metric_defs.h
+++ b/src/ray/stats/metric_defs.h
@@ -24,6 +24,16 @@
 ///
 /// You can follow these examples to define your metrics.
 
+///
+/// Common
+///
+static Histogram RedisLatency("redis_latency", "The latency of a Redis operation.", "us",
+                              {100, 200, 300, 400, 500, 600, 700, 800, 900, 1000},
+                              {CustomKey});
+
+///
+/// Raylet Metrics
+///
 static Gauge CurrentWorker("current_worker",
                            "This metric is used for reporting states of workers."
                            "Through this, we can see the worker's state on dashboard.",
@@ -36,10 +46,6 @@ static Gauge CurrentDriver("current_driver",
 static Count TaskCountReceived("task_count_received",
                                "Number of tasks received by raylet.", "pcs", {});
 
-static Histogram RedisLatency("redis_latency", "The latency of a Redis operation.", "us",
-                              {100, 200, 300, 400, 500, 600, 700, 800, 900, 1000},
-                              {CustomKey});
-
 static Gauge LocalAvailableResource("local_available_resource",
                                     "The available resources on this node.", "pcs",
                                     {ResourceNameKey});
diff --git a/src/ray/stats/metric_exporter.cc b/src/ray/stats/metric_exporter.cc
index 306a4354e..84fd27ac2 100644
--- a/src/ray/stats/metric_exporter.cc
+++ b/src/ray/stats/metric_exporter.cc
@@ -29,6 +29,7 @@ void MetricExporter::ExportToPoints(
   if (view_data.size() == 0) {
     return;
   }
+
   // NOTE(lingxuan.zlx): No sampling in histogram data, so all points all be filled in.
   std::unordered_map<std::string, std::string> tags;
   for (size_t i = 0; i < view_data.begin()->first.size(); ++i) {
@@ -104,5 +105,6 @@ void MetricExporter::ExportViewData(
   RAY_LOG(DEBUG) << "Point size : " << points.size();
   metric_exporter_client_->ReportMetrics(points);
 }
+
 }  // namespace stats
 }  // namespace ray
diff --git a/src/ray/stats/metric_exporter_client_test.cc b/src/ray/stats/metric_exporter_client_test.cc
index a1b39c299..455f020c6 100644
--- a/src/ray/stats/metric_exporter_client_test.cc
+++ b/src/ray/stats/metric_exporter_client_test.cc
@@ -31,6 +31,7 @@ namespace ray {
 using namespace stats;
 
 const size_t kMockReportBatchSize = 10;
+const int MetricsAgentPort = 10054;
 
 class MockExporterClient1 : public MetricExporterDecorator {
  public:
@@ -123,17 +124,14 @@ class MetricExporterClientTest : public ::testing::Test {
     exporter.reset(new stats::StdoutExporterClient());
     mock1.reset(new MockExporterClient1(exporter));
     mock2.reset(new MockExporterClient2(mock1));
-    ray::stats::Init(global_tags, 10054, io_service_, mock2, kMockReportBatchSize);
+    ray::stats::Init(global_tags, MetricsAgentPort, mock2, kMockReportBatchSize);
   }
 
   virtual void TearDown() override { Shutdown(); }
 
-  void Shutdown() {
-    opencensus::stats::StatsExporterImpl::Get()->ClearHandlersForTesting();
-  }
+  void Shutdown() { ray::stats::Shutdown(); }
 
  protected:
-  boost::asio::io_service io_service_;
   std::shared_ptr<MetricExporterClient> exporter;
   std::shared_ptr<MockExporterClient1> mock1;
   std::shared_ptr<MockExporterClient2> mock2;
diff --git a/src/ray/stats/stats.h b/src/ray/stats/stats.h
index d1de95902..668288a58 100644
--- a/src/ray/stats/stats.h
+++ b/src/ray/stats/stats.h
@@ -18,8 +18,8 @@
 #include <string>
 #include <unordered_map>
 
-#include "opencensus/exporters/stats/prometheus/prometheus_exporter.h"
-#include "opencensus/exporters/stats/stdout/stdout_exporter.h"
+#include "absl/synchronization/mutex.h"
+
 #include "opencensus/stats/internal/delta_producer.h"
 #include "opencensus/stats/stats.h"
 #include "opencensus/tags/tag_key.h"
@@ -27,6 +27,7 @@
 #include "ray/stats/metric.h"
 #include "ray/stats/metric_exporter.h"
 #include "ray/stats/metric_exporter_client.h"
+#include "ray/util/io_service_pool.h"
 #include "ray/util/logging.h"
 
 namespace ray {
@@ -38,38 +39,75 @@ namespace stats {
 /// Include metric_defs.h to define measure items.
 #include "ray/stats/metric_defs.h"
 
-/// Initialize stats.
-static inline void Init(
-    const TagsType &global_tags, const int metrics_agent_port,
-    boost::asio::io_service &io_service,
-    std::shared_ptr<MetricExporterClient> exporter_to_use = nullptr,
-    int64_t metrics_report_batch_size = RayConfig::instance().metrics_report_batch_size(),
-    bool disable_stats = !RayConfig::instance().enable_metrics_collection()) {
+// TODO(sang) Put all states and logic into a singleton class Stats.
+static std::shared_ptr<IOServicePool> metrics_io_service_pool;
+static std::shared_ptr<MetricExporterClient> exporter;
+static absl::Mutex stats_mutex;
+
+/// Initialize stats for a process.
+/// NOTE:
+/// - stats::Init should be called only once per PROCESS. Redundant calls will be just
+/// ignored.
+/// - If you want to reinitialize, you should call stats::Shutdown().
+/// - It is thread-safe.
+/// We recommend you to use this only once inside a main script and add Shutdown() method
+/// to any signal handler.
+/// \param global_tags[in] Tags that will be appended to all metrics in this process.
+/// \param metrics_agent_port[in] The port to export metrics at each node.
+/// \param exporter_to_use[in] The exporter client you will use for this process' metrics.
+static inline void Init(const TagsType &global_tags, const int metrics_agent_port,
+                        std::shared_ptr<MetricExporterClient> exporter_to_use = nullptr,
+                        int64_t metrics_report_batch_size =
+                            RayConfig::instance().metrics_report_batch_size()) {
+  absl::MutexLock lock(&stats_mutex);
+  if (StatsConfig::instance().IsInitialized()) {
+    RAY_CHECK(metrics_io_service_pool != nullptr);
+    RAY_CHECK(exporter != nullptr);
+    return;
+  }
+
+  RAY_CHECK(metrics_io_service_pool == nullptr);
+  RAY_CHECK(exporter == nullptr);
+  bool disable_stats = !RayConfig::instance().enable_metrics_collection();
   StatsConfig::instance().SetIsDisableStats(disable_stats);
   if (disable_stats) {
     RAY_LOG(INFO) << "Disabled stats.";
     return;
   }
 
-  // Force to have a singleton exporter.
-  static std::shared_ptr<MetricExporterClient> exporter;
-  // Default exporter is metrics agent exporter.
+  metrics_io_service_pool = std::make_shared<IOServicePool>(1);
+  metrics_io_service_pool->Run();
+  boost::asio::io_service *metrics_io_service = metrics_io_service_pool->Get();
+  RAY_CHECK(metrics_io_service != nullptr);
+
+  // Default exporter is a metrics agent exporter.
   if (exporter_to_use == nullptr) {
     std::shared_ptr<MetricExporterClient> stdout_exporter(new StdoutExporterClient());
     exporter.reset(new MetricsAgentExporter(stdout_exporter, metrics_agent_port,
-                                            io_service, "127.0.0.1"));
+                                            (*metrics_io_service), "127.0.0.1"));
   } else {
     exporter = exporter_to_use;
   }
 
-  // TODO(sang): Currently, we don't do any cleanup. This can lead us to lose last 10
-  // seconds data before we exit the main script.
   MetricExporter::Register(exporter, metrics_report_batch_size);
   opencensus::stats::StatsExporter::SetInterval(
       StatsConfig::instance().GetReportInterval());
   opencensus::stats::DeltaProducer::Get()->SetHarvestInterval(
       StatsConfig::instance().GetHarvestInterval());
   StatsConfig::instance().SetGlobalTags(global_tags);
+  StatsConfig::instance().SetIsInitialized(true);
+}
+
+/// Shutdown the initialized stats library.
+/// This cleans up various threads and metadata for stats library.
+static inline void Shutdown() {
+  // TODO(sang): Harvest thread is not currently cleaned up.
+  absl::MutexLock lock(&stats_mutex);
+  metrics_io_service_pool->Stop();
+  opencensus::stats::StatsExporter::Shutdown();
+  metrics_io_service_pool = nullptr;
+  exporter = nullptr;
+  StatsConfig::instance().SetIsInitialized(false);
 }
 
 }  // namespace stats
diff --git a/src/ray/stats/stats_test.cc b/src/ray/stats/stats_test.cc
index 1546c398b..327d681af 100644
--- a/src/ray/stats/stats_test.cc
+++ b/src/ray/stats/stats_test.cc
@@ -25,6 +25,8 @@
 
 namespace ray {
 
+const int MetricsAgentPort = 10054;
+
 class MockExporter : public opencensus::stats::StatsExporter::Handler {
  public:
   static void Register() {
@@ -62,7 +64,7 @@ uint32_t kReportFlushInterval = 500;
 
 class StatsTest : public ::testing::Test {
  public:
-  void SetUp() {
+  void SetUp() override {
     absl::Duration report_interval = absl::Milliseconds(kReportFlushInterval);
     absl::Duration harvest_interval = absl::Milliseconds(kReportFlushInterval / 2);
     ray::stats::StatsConfig::instance().SetReportInterval(report_interval);
@@ -71,14 +73,13 @@ class StatsTest : public ::testing::Test {
                                          {stats::WorkerPidKey, "1000"}};
     std::shared_ptr<stats::MetricExporterClient> exporter(
         new stats::StdoutExporterClient());
-    ray::stats::Init(global_tags, 10054, io_service_, exporter);
+    ray::stats::Init(global_tags, MetricsAgentPort, exporter);
     MockExporter::Register();
   }
 
-  void Shutdown() {}
+  virtual void TearDown() override { Shutdown(); }
 
- private:
-  boost::asio::io_service io_service_;
+  void Shutdown() { ray::stats::Shutdown(); }
 };
 
 TEST_F(StatsTest, F) {
@@ -88,6 +89,36 @@ TEST_F(StatsTest, F) {
   }
 }
 
+TEST_F(StatsTest, InitializationTest) {
+  // Do initialization multiple times and make sure only the first initialization
+  // was applied.
+  ASSERT_TRUE(ray::stats::StatsConfig::instance().IsInitialized());
+  auto test_tag_value_that_shouldnt_be_applied = "TEST";
+  for (size_t i = 0; i < 20; ++i) {
+    std::shared_ptr<stats::MetricExporterClient> exporter(
+        new stats::StdoutExporterClient());
+    ray::stats::Init({{stats::LanguageKey, test_tag_value_that_shouldnt_be_applied}},
+                     MetricsAgentPort, exporter);
+  }
+
+  auto &first_tag = ray::stats::StatsConfig::instance().GetGlobalTags()[0];
+  ASSERT_TRUE(first_tag.second != test_tag_value_that_shouldnt_be_applied);
+
+  ray::stats::Shutdown();
+  ASSERT_FALSE(ray::stats::StatsConfig::instance().IsInitialized());
+
+  // Reinitialize. It should be initialized now.
+  const stats::TagsType global_tags = {
+      {stats::LanguageKey, test_tag_value_that_shouldnt_be_applied}};
+  std::shared_ptr<stats::MetricExporterClient> exporter(
+      new stats::StdoutExporterClient());
+
+  ray::stats::Init(global_tags, MetricsAgentPort, exporter);
+  ASSERT_TRUE(ray::stats::StatsConfig::instance().IsInitialized());
+  auto &new_first_tag = ray::stats::StatsConfig::instance().GetGlobalTags()[0];
+  ASSERT_TRUE(new_first_tag.second == test_tag_value_that_shouldnt_be_applied);
+}
+
 }  // namespace ray
 
 int main(int argc, char **argv) {
diff --git a/src/ray/stats/tag_defs.h b/src/ray/stats/tag_defs.h
index 28edd54b7..462a05f2d 100644
--- a/src/ray/stats/tag_defs.h
+++ b/src/ray/stats/tag_defs.h
@@ -37,3 +37,5 @@ static const TagKeyType DriverPidKey = TagKeyType::Register("DriverPid");
 static const TagKeyType ResourceNameKey = TagKeyType::Register("ResourceName");
 
 static const TagKeyType ValueTypeKey = TagKeyType::Register("ValueType");
+
+static const TagKeyType ActorIdKey = TagKeyType::Register("ActorId");
diff --git a/thirdparty/patches/opencensus-cpp-shutdown-api.patch b/thirdparty/patches/opencensus-cpp-shutdown-api.patch
new file mode 100644
index 000000000..62f7777ff
--- /dev/null
+++ b/thirdparty/patches/opencensus-cpp-shutdown-api.patch
@@ -0,0 +1,80 @@
+diff --git opencensus/stats/internal/stats_exporter.cc b/opencensus/stats/internal/stats_exporter.cc
+--- opencensus/stats/internal/stats_exporter.cc
++++ opencensus/stats/internal/stats_exporter.cc
+@@ -95,25 +95,51 @@ void StatsExporterImpl::ClearHandlersForTesting() {
+ }
+ 
+ void StatsExporterImpl::StartExportThread() EXCLUSIVE_LOCKS_REQUIRED(mu_) {
+-  t_ = std::thread(&StatsExporterImpl::RunWorkerLoop, this);
+   thread_started_ = true;
++  t_ = std::thread(&StatsExporterImpl::RunWorkerLoop, this);
++}
++
++void StatsExporterImpl::Shutdown() {
++  absl::MutexLock l(&mu_);
++  if (!thread_started_) {
++    return;
++  }
++  thread_started_ = false;
++  // Join loop thread when shutdown.
++  if (t_.joinable()) {
++    t_.join();
++  }
+ }
+ 
+ void StatsExporterImpl::RunWorkerLoop() {
+   absl::Time next_export_time = GetNextExportTime();
+-  while (true) {
++  bool thread_started = false;
++  {
++    absl::MutexLock l(&mu_);
++    bool thread_started = thread_started_;
++  }
++  while (thread_started) {
+     // SleepFor() returns immediately when given a negative duration.
+     absl::SleepFor(next_export_time - absl::Now());
+     // In case the last export took longer than the export interval, we
+     // calculate the next time from now.
+     next_export_time = GetNextExportTime();
+     Export();
++    {
++      absl::MutexLock l(&mu_);
++      thread_started = thread_started_;
++    }
+   }
+ }
+ 
+ // StatsExporter
+ // -------------
+ 
++void StatsExporter::Shutdown() {
++  StatsExporterImpl::Get()->Shutdown();
++  StatsExporterImpl::Get()->ClearHandlersForTesting();
++}
++
+ // static
+ void StatsExporter::SetInterval(absl::Duration interval) {
+   StatsExporterImpl::Get()->SetInterval(interval);
+diff --git opencensus/stats/internal/stats_exporter_impl.h b/opencensus/stats/internal/stats_exporter_impl.h
+--- opencensus/stats/internal/stats_exporter_impl.h
++++ opencensus/stats/internal/stats_exporter_impl.h
+@@ -35,6 +35,7 @@ class StatsExporterImpl {
+   static StatsExporterImpl* Get();
+   void SetInterval(absl::Duration interval);
+   absl::Time GetNextExportTime() const;
++  void Shutdown();
+   void AddView(const ViewDescriptor& view);
+   void RemoveView(absl::string_view name);
+ 
+diff --git opencensus/stats/stats_exporter.h b/opencensus/stats/stats_exporter.h
+--- opencensus/stats/stats_exporter.h
++++ opencensus/stats/stats_exporter.h
+@@ -45,6 +45,8 @@ class StatsExporter final {
+   // Removes the view with 'name' from the registry, if one is registered.
+   static void RemoveView(absl::string_view name);
+ 
++  static void Shutdown();
++
+   // StatsExporter::Handler is the interface for push exporters that export
+   // recorded data for registered views. The exporter should provide a static
+   // Register() method that takes any arguments needed by the exporter (e.g. a