diff --git a/src/ray/common/client_connection.h b/src/ray/common/client_connection.h
index 89d30fbbcdbc..ec77edd79248 100644
--- a/src/ray/common/client_connection.h
+++ b/src/ray/common/client_connection.h
@@ -44,6 +44,9 @@ Status ConnectSocketRetry(local_stream_socket &socket,
 /// can be used to write messages synchronously to the server.
 class ServerConnection : public std::enable_shared_from_this<ServerConnection> {
  public:
+  ServerConnection(const ServerConnection &) = delete;
+  ServerConnection &operator=(const ServerConnection &) = delete;
+
   /// ServerConnection destructor.
   virtual ~ServerConnection();
 
@@ -187,6 +190,9 @@ class ClientConnection : public ServerConnection {
  public:
   using std::enable_shared_from_this<ServerConnection>::shared_from_this;
 
+  ClientConnection(const ClientConnection &) = delete;
+  ClientConnection &operator=(const ClientConnection &) = delete;
+
   /// Allocate a new node client connection.
   ///
   /// \param new_client_handler A reference to the client handler.
diff --git a/src/ray/raylet/node_manager.cc b/src/ray/raylet/node_manager.cc
index 7d4a40b50c24..cb99b7d040e4 100644
--- a/src/ray/raylet/node_manager.cc
+++ b/src/ray/raylet/node_manager.cc
@@ -1297,7 +1297,7 @@ void NodeManager::ProcessRegisterClientRequestMessage(
              worker_type == rpc::WorkerType::RESTORE_WORKER) {
     RAY_CHECK(job_id.IsNil());
   }
-  auto worker = std::dynamic_pointer_cast<WorkerInterface>(
+  auto worker = std::static_pointer_cast<WorkerInterface>(
       std::make_shared<Worker>(job_id,
                                runtime_env_hash,
                                worker_id,
diff --git a/src/ray/util/process.cc b/src/ray/util/process.cc
index 34be370198d4..de29aadd6b08 100644
--- a/src/ray/util/process.cc
+++ b/src/ray/util/process.cc
@@ -88,11 +88,12 @@ class ProcessFD {
   ~ProcessFD();
   ProcessFD();
   ProcessFD(pid_t pid, intptr_t fd = -1);
-  ProcessFD(const ProcessFD &other);
   ProcessFD(ProcessFD &&other);
-  ProcessFD &operator=(const ProcessFD &other);
   ProcessFD &operator=(ProcessFD &&other);
-  intptr_t CloneFD() const;
+
+  ProcessFD(const ProcessFD &other) = delete;
+  ProcessFD &operator=(const ProcessFD &other) = delete;
+
   void CloseFD();
   intptr_t GetFD() const;
   pid_t GetId() const;
@@ -217,17 +218,7 @@ class ProcessFD {
   }
 };
 
-ProcessFD::~ProcessFD() {
-  if (fd_ != -1) {
-    bool success;
-#ifdef _WIN32
-    success = !!CloseHandle(reinterpret_cast<HANDLE>(fd_));
-#else
-    success = close(static_cast<int>(fd_)) == 0;
-#endif
-    RAY_CHECK(success) << "error " << errno << " closing process " << pid_ << " FD";
-  }
-}
+ProcessFD::~ProcessFD() { CloseFD(); }
 
 ProcessFD::ProcessFD() : pid_(-1), fd_(-1) {}
 
@@ -277,18 +268,8 @@ ProcessFD::ProcessFD(pid_t pid, intptr_t fd) : pid_(pid), fd_(fd) {
   }
 }
 
-ProcessFD::ProcessFD(const ProcessFD &other) : ProcessFD(other.pid_, other.CloneFD()) {}
-
 ProcessFD::ProcessFD(ProcessFD &&other) : ProcessFD() { *this = std::move(other); }
 
-ProcessFD &ProcessFD::operator=(const ProcessFD &other) {
-  if (this != &other) {
-    // Construct a copy, then call the move constructor
-    *this = static_cast<ProcessFD>(other);
-  }
-  return *this;
-}
-
 ProcessFD &ProcessFD::operator=(ProcessFD &&other) {
   if (this != &other) {
     // We use swap() to make sure the argument is actually moved from
@@ -299,32 +280,19 @@ ProcessFD &ProcessFD::operator=(ProcessFD &&other) {
   return *this;
 }
 
-intptr_t ProcessFD::CloneFD() const {
-  intptr_t fd;
+void ProcessFD::CloseFD() {
   if (fd_ != -1) {
+    bool success;
 #ifdef _WIN32
-    HANDLE handle;
-    BOOL inheritable = FALSE;
-    fd = DuplicateHandle(GetCurrentProcess(),
-                         reinterpret_cast<HANDLE>(fd_),
-                         GetCurrentProcess(),
-                         &handle,
-                         0,
-                         inheritable,
-                         DUPLICATE_SAME_ACCESS)
-             ? reinterpret_cast<intptr_t>(handle)
-             : -1;
+    success = !!CloseHandle(reinterpret_cast<HANDLE>(fd_));
 #else
-    fd = dup(static_cast<int>(fd_));
+    success = close(static_cast<int>(fd_)) == 0;
 #endif
-    RAY_DCHECK(fd != -1);
-  } else {
-    fd = -1;
+    RAY_CHECK(success) << "error " << errno << " closing process " << pid_ << " FD";
   }
-  return fd;
-}
 
-void ProcessFD::CloseFD() { fd_ = -1; }
+  fd_ = -1;
+}
 
 intptr_t ProcessFD::GetFD() const { return fd_; }