[Core] Remove ray._raylet.check_health (ray-project#47526)

Signed-off-by: Jiajun Yao <[email protected]>
Signed-off-by: ujjawal-khare <[email protected]>

src/ray/gcs/gcs_client/gcs_client.cc

@@ -718,6 +718,36 @@ std::unordered_map<std::string, std::string> PythonGetNodeLabels(
                                                       node_info.labels().end());
 }
 
+/// Creates a singleton thread that runs an io_service.
+/// All ConnectToGcsStandalone calls will share this io_service.
+class SingletonIoContext {
+ public:
+  static SingletonIoContext &Instance() {
+    static SingletonIoContext instance;
+    return instance;
+  }
+
+  instrumented_io_context &GetIoService() { return io_service_; }
+
+ private:
+  SingletonIoContext() : work_(io_service_) {
+    io_thread_ = std::thread([this] {
+      SetThreadName("singleton_io_context.gcs_client");
+      io_service_.run();
+    });
+  }
+  ~SingletonIoContext() {
+    io_service_.stop();
+    if (io_thread_.joinable()) {
+      io_thread_.join();
+    }
+  }
+
+  instrumented_io_context io_service_;
+  boost::asio::io_service::work work_;  // to keep io_service_ running
+  std::thread io_thread_;
+};
+
 Status ConnectOnSingletonIoContext(GcsClient &gcs_client, int64_t timeout_ms) {
   static InstrumentedIOContextWithThread io_context("gcs_client_io_service");
   instrumented_io_context &io_service = io_context.GetIoService();