diff --git a/src/utils/socket.h b/src/utils/socket.h
deleted file mode 100644
index 73caa2fea..000000000
--- a/src/utils/socket.h
+++ /dev/null
@@ -1,389 +0,0 @@
-#ifndef XGBOOST_UTILS_SOCKET_H
-#define XGBOOST_UTILS_SOCKET_H
-/*!
- * \file socket.h
- * \brief this file aims to provide a wrapper of sockets
- * \author Tianqi Chen
- */
-#if defined(_WIN32)
-#include <winsock2.h>
-#include <ws2tcpip.h>
-#else
-#include <fcntl.h>
-#include <netdb.h>
-#include <errno.h>
-#include <unistd.h>
-#include <arpa/inet.h>
-#include <netinet/in.h>
-#include <sys/socket.h>
-#include <sys/select.h>
-#endif
-#include <string>
-#include <cstring>
-#include "./utils.h"
-
-namespace xgboost {
-namespace utils {
-#if defined(_WIN32)
-typedef int ssize_t;
-typedef int sock_size_t;
-#else
-typedef int SOCKET;
-typedef size_t sock_size_t;
-const int INVALID_SOCKET = -1;
-#endif
-
-/*! \brief data structure for network address */
-struct SockAddr {
-  sockaddr_in addr;
-  // constructor
-  SockAddr(void) {}
-  SockAddr(const char *url, int port) {
-    this->Set(url, port);
-  }
-  inline static std::string GetHostName(void) {
-    std::string buf; buf.resize(256);
-    utils::Check(gethostname(&buf[0], 256) != -1, "fail to get host name");
-    return std::string(buf.c_str());
-  }
-  /*! 
-   * \brief set the address
-   * \param url the url of the address
-   * \param port the port of address
-   */
-  inline void Set(const char *host, int port) {
-    hostent *hp = gethostbyname(host);
-    Check(hp != NULL, "cannot obtain address of %s", host);
-    memset(&addr, 0, sizeof(addr));
-    addr.sin_family = AF_INET;
-    addr.sin_port = htons(port);
-    memcpy(&addr.sin_addr, hp->h_addr_list[0], hp->h_length);
-  }
-  /*! \brief return port of the address*/
-  inline int port(void) const {
-    return ntohs(addr.sin_port);
-  }
-  /*! \return a string representation of the address */
-  inline std::string AddrStr(void) const {
-    std::string buf; buf.resize(256);
-#ifdef _WIN32
-    const char *s = inet_ntop(AF_INET, (PVOID)&addr.sin_addr, &buf[0], buf.length());
-#else
-    const char *s = inet_ntop(AF_INET, &addr.sin_addr, &buf[0], buf.length());
-#endif
-    Assert(s != NULL, "cannot decode address");
-    return std::string(s);
-  }
-};
-/*! 
- * \brief a wrapper of TCP socket that hopefully be cross platform
- */
-class TCPSocket {
- public:
-  /*! \brief the file descriptor of socket */
-  SOCKET sockfd;
-  // constructor
-  TCPSocket(void) : sockfd(INVALID_SOCKET) {
-  }
-  explicit TCPSocket(SOCKET sockfd) : sockfd(sockfd) {
-  }
-  ~TCPSocket(void) {
-    // do nothing in destructor
-    // user need to take care of close
-  }
-  // default conversion to int
-  inline operator SOCKET() const {
-    return sockfd;
-  }
-  /*!
-   * \brief create the socket, call this before using socket
-   * \param af domain
-   */
-  inline void Create(int af = PF_INET) {
-    sockfd = socket(PF_INET, SOCK_STREAM, 0);
-    if (sockfd == INVALID_SOCKET) {
-      SockError("Create");
-    }
-  }
-  /*!
-   * \brief start up the socket module
-   *   call this before using the sockets
-   */
-  inline static void Startup(void) {
-#ifdef _WIN32
-    WSADATA wsa_data;
-    if (WSAStartup(MAKEWORD(2, 2), &wsa_data) != -1) {
-      SockError("Startup");
-    }
-    if (LOBYTE(wsa_data.wVersion) != 2 || HIBYTE(wsa_data.wVersion) != 2) {
-      WSACleanup();
-      utils::Error("Could not find a usable version of Winsock.dll\n");
-    }
-#endif
-  }
-  /*! 
-   * \brief shutdown the socket module after use, all sockets need to be closed
-   */  
-  inline static void Finalize(void) {
-#ifdef _WIN32
-    WSACleanup();
-#endif
-  }
-  /*! 
-   * \brief set this socket to use non-blocking mode
-   * \param non_block whether set it to be non-block, if it is false
-   *        it will set it back to block mode
-   */
-  inline void SetNonBlock(bool non_block) {
-#ifdef _WIN32  
-    u_long mode = non_block ? 1 : 0;
-    if (ioctlsocket(sockfd, FIONBIO, &mode) != NO_ERROR) {
-      SockError("SetNonBlock");
-    }
-#else
-    int flag = fcntl(sockfd, F_GETFL, 0);
-    if (flag == -1) {
-      SockError("SetNonBlock-1");
-    }
-    if (non_block) {
-      flag |= O_NONBLOCK;
-    } else {
-      flag &= ~O_NONBLOCK;
-    }
-    if (fcntl(sockfd, F_SETFL, flag) == -1) {
-      SockError("SetNonBlock-2");
-    }
-#endif
-  }
-  /*!
-   * \brief perform listen of the socket
-   * \param backlog backlog parameter
-   */
-  inline void Listen(int backlog = 16) {
-    listen(sockfd, backlog);
-  }
-  /*! \brief get a new connection */
-  TCPSocket Accept(void) {
-    SOCKET newfd = accept(sockfd, NULL, NULL);
-    if (newfd == INVALID_SOCKET) {
-      SockError("Accept");
-    }
-    return TCPSocket(newfd);
-  }
-  /*! 
-   * \brief bind the socket to an address 
-   * \param addr
-   */
-  inline void Bind(const SockAddr &addr) {
-    if (bind(sockfd, (sockaddr*)&addr.addr, sizeof(addr.addr)) == -1) {
-      SockError("Bind");
-    }
-  }
-  /*! 
-   * \brief try bind the socket to host, from start_port to end_port
-   * \param start_port starting port number to try
-   * \param end_port ending port number to try
-   * \param out_addr the binding address, if successful
-   * \return whether the binding is successful
-   */
-  inline int TryBindHost(int start_port, int end_port) {    
-    for (int port = start_port; port < end_port; ++port) {
-      SockAddr addr("0.0.0.0", port);
-      if (bind(sockfd, (sockaddr*)&addr.addr, sizeof(addr.addr)) == 0) {
-        return port;
-      }
-      if (errno != EADDRINUSE) {
-        SockError("TryBindHost");
-      }
-    }
-    return -1;
-  }                      
-  /*! 
-   * \brief connect to an address 
-   * \param addr the address to connect to
-   */
-  inline void Connect(const SockAddr &addr) {
-    if (connect(sockfd, (sockaddr*)&addr.addr, sizeof(addr.addr)) == -1) {
-      SockError("Connect");
-    }
-  }
-  /*! \brief close the connection */
-  inline void Close(void) {
-    if (sockfd != -1) {
-#ifdef _WIN32
-      closesocket(sockfd);
-#else
-	  close(sockfd);
-#endif
-	  sockfd = INVALID_SOCKET;
-    } else {
-      Error("TCPSocket::Close double close the socket or close without create");
-    }
-  }
-  /*!
-   * \brief send data using the socket 
-   * \param buf the pointer to the buffer
-   * \param len the size of the buffer
-   * \param flags extra flags
-   * \return size of data actually sent
-   */
-  inline size_t Send(const void *buf_, size_t len, int flag = 0) {
-	const char *buf = reinterpret_cast<const char*>(buf_);
-    if (len == 0) return 0;
-    ssize_t ret = send(sockfd, buf, static_cast<sock_size_t>(len), flag);
-    if (ret == -1) {
-      if (errno == EAGAIN || errno == EWOULDBLOCK) return 0;
-      SockError("Send");
-    }
-    return ret;
-  }  
-  /*! 
-   * \brief receive data using the socket 
-   * \param buf_ the pointer to the buffer
-   * \param len the size of the buffer
-   * \param flags extra flags
-   * \return size of data actually received 
-   */
-  inline size_t Recv(void *buf_, size_t len, int flags = 0) {
-	char *buf = reinterpret_cast<char*>(buf_);
-    if (len == 0) return 0;    
-    ssize_t ret = recv(sockfd, buf, static_cast<sock_size_t>(len), flags);
-    if (ret == -1) {
-      if (errno == EAGAIN || errno == EWOULDBLOCK) return 0;
-      SockError("Recv");
-    }
-    return ret;
-  } 
-  /*!
-   * \brief peform block write that will attempt to send all data out
-   *    can still return smaller than request when error occurs
-   * \param buf the pointer to the buffer
-   * \param len the size of the buffer
-   * \return size of data actually sent
-   */
-  inline size_t SendAll(const void *buf_, size_t len) {
-    const char *buf = reinterpret_cast<const char*>(buf_);
-    size_t ndone = 0;
-    while (ndone <  len) {
-      ssize_t ret = send(sockfd, buf, static_cast<ssize_t>(len - ndone), 0);
-      if (ret == -1) {
-        if (errno == EAGAIN || errno == EWOULDBLOCK) return ndone;
-        SockError("Recv");
-      }
-      buf += ret;
-      ndone += ret;
-    }
-    return ndone;
-  }
-  /*!
-   * \brief peforma block read that will attempt to read all data
-   *    can still return smaller than request when error occurs
-   * \param buf_ the buffer pointer
-   * \param len length of data to recv
-   * \return size of data actually sent
-   */
-  inline size_t RecvAll(void *buf_, size_t len) {
-    char *buf = reinterpret_cast<char*>(buf_);
-    size_t ndone = 0;
-    while (ndone <  len) {
-      ssize_t ret = recv(sockfd, buf, static_cast<sock_size_t>(len - ndone), MSG_WAITALL);
-      if (ret == -1) {
-        if (errno == EAGAIN || errno == EWOULDBLOCK) return ndone;
-        SockError("Recv");
-      }
-      if (ret == 0) return ndone;
-      buf += ret;
-      ndone += ret;
-    }
-    return ndone;
-  }
-
- private:
-  // report an socket error
-  inline static void SockError(const char *msg) {
-    int errsv = errno;
-    Error("Socket %s Error:%s", msg, strerror(errsv));
-  }
-};
-/*! \brief helper data structure to perform select */
-struct SelectHelper {
- public:
-  SelectHelper(void) {
-    this->Clear();
-  }
-  /*!
-   * \brief add file descriptor to watch for read 
-   * \param fd file descriptor to be watched
-   */
-  inline void WatchRead(SOCKET fd) {
-    read_fds.push_back(fd);
-    if (fd > maxfd) maxfd = fd;
-  }
-  /*!
-   * \brief add file descriptor to watch for write
-   * \param fd file descriptor to be watched
-   */
-  inline void WatchWrite(SOCKET fd) {
-    write_fds.push_back(fd);
-    if (fd > maxfd) maxfd = fd;
-  }
-  /*!
-   * \brief Check if the descriptor is ready for read
-   * \param fd file descriptor to check status
-   */
-  inline bool CheckRead(SOCKET fd) const {
-    return FD_ISSET(fd, &read_set) != 0;
-  }
-  /*!
-   * \brief Check if the descriptor is ready for write
-   * \param fd file descriptor to check status
-   */
-  inline bool CheckWrite(SOCKET fd) const {
-    return FD_ISSET(fd, &write_set) != 0;
-  }
-  /*!
-   * \brief clear all the monitored descriptors
-   */
-  inline void Clear(void) {
-    read_fds.clear();
-    write_fds.clear();
-    maxfd = 0;
-  }
-  /*!
-   * \brief peform select on the set defined
-   * \param timeout specify timeout in micro-seconds(ms) if equals 0, means select will always block
-   * \return number of active descriptors selected
-   */
-  inline int Select(long timeout = 0) {
-    FD_ZERO(&read_set);
-    FD_ZERO(&write_set);
-    for (size_t i = 0; i < read_fds.size(); ++i) {
-      FD_SET(read_fds[i], &read_set);
-    } 
-    for (size_t i = 0; i < write_fds.size(); ++i) {
-      FD_SET(write_fds[i], &write_set);
-    }
-    int ret;
-    if (timeout == 0) {
-      ret = select(static_cast<int>(maxfd + 1), &read_set, &write_set, NULL, NULL);
-    } else {
-      timeval tm;
-      tm.tv_usec = (timeout % 1000) * 1000;
-      tm.tv_sec = timeout / 1000;
-      ret = select(static_cast<int>(maxfd + 1), &read_set, &write_set, NULL, &tm);
-    }
-    if (ret == -1) {
-      int errsv = errno;
-      Error("Select Error: %s", strerror(errsv));
-    }
-    return ret;
-  }
-  
- private:
-  SOCKET maxfd; 
-  fd_set read_set, write_set;
-  std::vector<SOCKET> read_fds, write_fds;
-};
-}
-}
-#endif