X-Git-Url: https://git.m6w6.name/?a=blobdiff_plain;f=libmemcached%2Fconnect.cc;h=65be51a07f9a2c509f7dba7bc6c11043e358bc1a;hb=2e52a0a4fe2f17ea724a97409047874c341317ab;hp=f90cb6b057958ec3db6feedd35cbbf9c1914a7af;hpb=0fe409a0db64fc9d24a44ac363c502ea9e98857e;p=awesomized%2Flibmemcached

diff --git a/libmemcached/connect.cc b/libmemcached/connect.cc
index f90cb6b0..65be51a0 100644
--- a/libmemcached/connect.cc
+++ b/libmemcached/connect.cc
@@ -37,10 +37,24 @@
 
 
 #include <libmemcached/common.h>
+
+#include <cassert>
 #include <ctime>
 #include <sys/time.h>
 
-static memcached_return_t connect_poll(memcached_server_st *server)
+#ifndef SOCK_CLOEXEC 
+#  define SOCK_CLOEXEC 0
+#endif
+
+#ifndef SOCK_NONBLOCK 
+#  define SOCK_NONBLOCK 0
+#endif
+
+#ifndef FD_CLOEXEC
+# define FD_CLOEXEC 0
+#endif
+
+static memcached_return_t connect_poll(org::libmemcached::Instance* server)
 {
   struct pollfd fds[1];
   fds[0].fd= server->fd;
@@ -55,73 +69,87 @@ static memcached_return_t connect_poll(memcached_server_st *server)
 
   while (--loop_max) // Should only loop on cases of ERESTART or EINTR
   {
-    int error= poll(fds, 1, server->root->connect_timeout);
-    switch (error)
+    int number_of;
+    if ((number_of= poll(fds, 1, server->root->connect_timeout)) <= 0)
     {
-    case 1:
+      if (number_of == -1)
       {
-        int err;
-        socklen_t len= sizeof (err);
-        (void)getsockopt(server->fd, SOL_SOCKET, SO_ERROR, &err, &len);
-
-        // We check the value to see what happened wth the socket.
-        if (err == 0)
+        int local_errno= get_socket_errno(); // We cache in case closesocket() modifies errno
+        switch (local_errno)
         {
-          return MEMCACHED_SUCCESS;
-        }
-
-        return memcached_set_errno(*server, err, MEMCACHED_AT);
-      }
-    case 0:
-      {
-        return memcached_set_error(*server, MEMCACHED_TIMEOUT, MEMCACHED_AT);
-      }
-
-    default: // A real error occurred and we need to completely bail
-      switch (get_socket_errno())
-      {
 #ifdef TARGET_OS_LINUX
-      case ERESTART:
+        case ERESTART:
 #endif
-      case EINTR:
-        continue;
+        case EINTR:
+          continue;
+
+        case EFAULT:
+        case ENOMEM:
+          return memcached_set_error(*server, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT);
+
+        case EINVAL:
+          return memcached_set_error(*server, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT, memcached_literal_param("RLIMIT_NOFILE exceeded, or if OSX the timeout value was invalid"));
+
+        default: // This should not happen
+          if (fds[0].revents & POLLERR)
+          {
+            int err;
+            socklen_t len= sizeof(err);
+            if (getsockopt(server->fd, SOL_SOCKET, SO_ERROR, &err, &len) == 0)
+            {
+              if (err == 0)
+              {
+                // This should never happen, if it does? Punt.  
+                continue;
+              }
+              local_errno= err;
+            }
+          }
+
+          assert_msg(server->fd != INVALID_SOCKET, "poll() was passed an invalid file descriptor");
+          (void)closesocket(server->fd);
+          server->fd= INVALID_SOCKET;
+          server->state= MEMCACHED_SERVER_STATE_NEW;
 
-      case EFAULT:
-      case ENOMEM:
-        return memcached_set_error(*server, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT);
+          return memcached_set_errno(*server, local_errno, MEMCACHED_AT);
+        }
+      }
+      assert(number_of == 0);
 
-      case EINVAL:
-        return memcached_set_error(*server, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT, memcached_literal_param("RLIMIT_NOFILE exceeded, or if OSX the timeout value was invalid"));
+      server->io_wait_count.timeouts++;
+      return memcached_set_error(*server, MEMCACHED_TIMEOUT, MEMCACHED_AT);
+    }
 
-      default: // This should not happen
-        if (fds[0].revents & POLLERR)
-        {
-          int err;
-          socklen_t len= sizeof (err);
-          (void)getsockopt(server->fd, SOL_SOCKET, SO_ERROR, &err, &len);
-          memcached_set_errno(*server, (err == 0) ? get_socket_errno() : err, MEMCACHED_AT);
-        }
-        else
+    if (fds[0].revents & POLLERR or
+        fds[0].revents & POLLHUP or 
+        fds[0].revents & POLLNVAL)
+    {
+      int err;
+      socklen_t len= sizeof (err);
+      if (getsockopt(fds[0].fd, SOL_SOCKET, SO_ERROR, &err, &len) == 0)
+      {
+        // We check the value to see what happened wth the socket.
+        if (err == 0)
         {
-          memcached_set_errno(*server, get_socket_errno(), MEMCACHED_AT);
+          return MEMCACHED_SUCCESS;
         }
-
-        assert_msg(server->fd != INVALID_SOCKET, "poll() was passed an invalid file descriptor");
-        (void)closesocket(server->fd);
-        server->fd= INVALID_SOCKET;
-        server->state= MEMCACHED_SERVER_STATE_NEW;
-
-        return memcached_set_errno(*server, get_socket_errno(), MEMCACHED_AT);
+        errno= err;
       }
+
+      return memcached_set_errno(*server, err, MEMCACHED_AT);
     }
+    assert(fds[0].revents & POLLIN or fds[0].revents & POLLOUT);
+
+    return MEMCACHED_SUCCESS;
   }
 
   // This should only be possible from ERESTART or EINTR;
   return memcached_set_errno(*server, get_socket_errno(), MEMCACHED_AT);
 }
 
-static memcached_return_t set_hostinfo(memcached_server_st *server)
+static memcached_return_t set_hostinfo(org::libmemcached::Instance* server)
 {
+  assert(server->type != MEMCACHED_CONNECTION_UNIX_SOCKET);
   if (server->address_info)
   {
     freeaddrinfo(server->address_info);
@@ -130,8 +158,8 @@ static memcached_return_t set_hostinfo(memcached_server_st *server)
   }
 
   char str_port[NI_MAXSERV];
-  int length= snprintf(str_port, NI_MAXSERV, "%u", (uint32_t)server->port);
-  if (length >= NI_MAXSERV or length < 0)
+  int length= snprintf(str_port, NI_MAXSERV, "%u", uint32_t(server->port()));
+  if (length >= NI_MAXSERV or length <= 0)
   {
     return MEMCACHED_FAILURE;
   }
@@ -142,7 +170,7 @@ static memcached_return_t set_hostinfo(memcached_server_st *server)
 #if 0
   hints.ai_family= AF_INET;
 #endif
-  if (server->type == MEMCACHED_CONNECTION_UDP)
+  if (memcached_is_udp(server->root))
   {
     hints.ai_protocol= IPPROTO_UDP;
     hints.ai_socktype= SOCK_DGRAM;
@@ -153,7 +181,8 @@ static memcached_return_t set_hostinfo(memcached_server_st *server)
     hints.ai_protocol= IPPROTO_TCP;
   }
 
-  server->address_info= NULL;
+  assert(server->address_info == NULL);
+  assert(server->address_info_next == NULL);
   int errcode;
   switch(errcode= getaddrinfo(server->hostname, str_port, &hints, &server->address_info))
   {
@@ -161,19 +190,49 @@ static memcached_return_t set_hostinfo(memcached_server_st *server)
     break;
 
   case EAI_AGAIN:
+    if (server->address_info)
+    {
+      freeaddrinfo(server->address_info);
+      server->address_info= NULL;
+      server->address_info_next= NULL;
+    }
     return memcached_set_error(*server, MEMCACHED_TIMEOUT, MEMCACHED_AT, memcached_string_make_from_cstr(gai_strerror(errcode)));
 
   case EAI_SYSTEM:
+    if (server->address_info)
+    {
+      freeaddrinfo(server->address_info);
+      server->address_info= NULL;
+      server->address_info_next= NULL;
+    }
     return memcached_set_errno(*server, errno, MEMCACHED_AT, memcached_literal_param("getaddrinfo(EAI_SYSTEM)"));
 
   case EAI_BADFLAGS:
+    if (server->address_info)
+    {
+      freeaddrinfo(server->address_info);
+      server->address_info= NULL;
+      server->address_info_next= NULL;
+    }
     return memcached_set_error(*server, MEMCACHED_INVALID_ARGUMENTS, MEMCACHED_AT, memcached_literal_param("getaddrinfo(EAI_BADFLAGS)"));
 
   case EAI_MEMORY:
+    if (server->address_info)
+    {
+      freeaddrinfo(server->address_info);
+      server->address_info= NULL;
+      server->address_info_next= NULL;
+    }
     return memcached_set_error(*server, MEMCACHED_MEMORY_ALLOCATION_FAILURE, MEMCACHED_AT, memcached_literal_param("getaddrinfo(EAI_MEMORY)"));
 
   default:
     {
+      if (server->address_info)
+      {
+        freeaddrinfo(server->address_info);
+        server->address_info= NULL;
+        server->address_info_next= NULL;
+      }
       return memcached_set_error(*server, MEMCACHED_HOST_LOOKUP_FAILURE, MEMCACHED_AT, memcached_string_make_from_cstr(gai_strerror(errcode)));
     }
   }
@@ -183,7 +242,7 @@ static memcached_return_t set_hostinfo(memcached_server_st *server)
   return MEMCACHED_SUCCESS;
 }
 
-static inline void set_socket_nonblocking(memcached_server_st *server)
+static inline void set_socket_nonblocking(org::libmemcached::Instance* server)
 {
 #ifdef WIN32
   u_long arg= 1;
@@ -194,68 +253,71 @@ static inline void set_socket_nonblocking(memcached_server_st *server)
 #else
   int flags;
 
-  do
+  if (SOCK_NONBLOCK == 0)
   {
-    flags= fcntl(server->fd, F_GETFL, 0);
-  } while (flags == -1 && (errno == EINTR || errno == EAGAIN));
-
-  if (flags == -1)
-  {
-    memcached_set_errno(*server, errno, NULL);
-  }
-  else if ((flags & O_NONBLOCK) == 0)
-  {
-    int rval;
-
     do
     {
-      rval= fcntl(server->fd, F_SETFL, flags | O_NONBLOCK);
-    } while (rval == -1 && (errno == EINTR || errno == EAGAIN));
+      flags= fcntl(server->fd, F_GETFL, 0);
+    } while (flags == -1 && (errno == EINTR || errno == EAGAIN));
 
-    unlikely (rval == -1)
+    if (flags == -1)
     {
       memcached_set_errno(*server, errno, NULL);
     }
+    else if ((flags & O_NONBLOCK) == 0)
+    {
+      int rval;
+
+      do
+      {
+        rval= fcntl(server->fd, F_SETFL, flags | O_NONBLOCK);
+      } while (rval == -1 && (errno == EINTR or errno == EAGAIN));
+
+      if (rval == -1)
+      {
+        memcached_set_errno(*server, errno, NULL);
+      }
+    }
   }
 #endif
 }
 
-static void set_socket_options(memcached_server_st *server)
+static void set_socket_options(org::libmemcached::Instance* server)
 {
-  assert_msg(server->fd != -1, "invalid socket was passed to set_socket_options()");
+  assert_msg(server->fd != INVALID_SOCKET, "invalid socket was passed to set_socket_options()");
 
-  if (server->type == MEMCACHED_CONNECTION_UDP)
+  if (memcached_is_udp(server->root))
   {
     return;
   }
 
 #ifdef HAVE_SNDTIMEO
-  if (server->root->snd_timeout)
+  if (server->root->snd_timeout > 0)
   {
-    int error;
     struct timeval waittime;
 
-    waittime.tv_sec= 0;
-    waittime.tv_usec= server->root->snd_timeout;
+    waittime.tv_sec= server->root->snd_timeout / 1000000;
+    waittime.tv_usec= server->root->snd_timeout % 1000000;
 
-    error= setsockopt(server->fd, SOL_SOCKET, SO_SNDTIMEO,
-                      &waittime, (socklen_t)sizeof(struct timeval));
-    WATCHPOINT_ASSERT(error == 0);
+    int error= setsockopt(server->fd, SOL_SOCKET, SO_SNDTIMEO,
+                          &waittime, (socklen_t)sizeof(struct timeval));
+    (void)error;
+    assert(error == 0);
   }
 #endif
 
 #ifdef HAVE_RCVTIMEO
-  if (server->root->rcv_timeout)
+  if (server->root->rcv_timeout > 0)
   {
-    int error;
     struct timeval waittime;
 
-    waittime.tv_sec= 0;
-    waittime.tv_usec= server->root->rcv_timeout;
+    waittime.tv_sec= server->root->rcv_timeout / 1000000;
+    waittime.tv_usec= server->root->rcv_timeout % 1000000;
 
-    error= setsockopt(server->fd, SOL_SOCKET, SO_RCVTIMEO,
-                      &waittime, (socklen_t)sizeof(struct timeval));
-    WATCHPOINT_ASSERT(error == 0);
+    int error= setsockopt(server->fd, SOL_SOCKET, SO_RCVTIMEO,
+                          &waittime, (socklen_t)sizeof(struct timeval));
+    (void)(error);
+    assert(error == 0);
   }
 #endif
 
@@ -265,87 +327,97 @@ static void set_socket_options(memcached_server_st *server)
     int set= 1;
     int error= setsockopt(server->fd, SOL_SOCKET, SO_NOSIGPIPE, (void *)&set, sizeof(int));
 
+    assert(error == 0);
+
     // This is not considered a fatal error
     if (error == -1)
     {
-      WATCHPOINT_ERRNO(get_socket_errno());
+#if 0
       perror("setsockopt(SO_NOSIGPIPE)");
+#endif
     }
   }
 #endif
 
   if (server->root->flags.no_block)
   {
-    int error;
     struct linger linger;
 
     linger.l_onoff= 1;
     linger.l_linger= 0; /* By default on close() just drop the socket */
-    error= setsockopt(server->fd, SOL_SOCKET, SO_LINGER,
-                      &linger, (socklen_t)sizeof(struct linger));
-    WATCHPOINT_ASSERT(error == 0);
+    int error= setsockopt(server->fd, SOL_SOCKET, SO_LINGER,
+                          &linger, (socklen_t)sizeof(struct linger));
+    (void)(error);
+    assert(error == 0);
   }
 
   if (server->root->flags.tcp_nodelay)
   {
     int flag= 1;
-    int error;
 
-    error= setsockopt(server->fd, IPPROTO_TCP, TCP_NODELAY,
-                      &flag, (socklen_t)sizeof(int));
-    WATCHPOINT_ASSERT(error == 0);
+    int error= setsockopt(server->fd, IPPROTO_TCP, TCP_NODELAY,
+                          &flag, (socklen_t)sizeof(int));
+    (void)(error);
+    assert(error == 0);
   }
 
   if (server->root->flags.tcp_keepalive)
   {
     int flag= 1;
-    int error;
 
-    error= setsockopt(server->fd, SOL_SOCKET, SO_KEEPALIVE,
+    int error= setsockopt(server->fd, SOL_SOCKET, SO_KEEPALIVE,
                       &flag, (socklen_t)sizeof(int));
-    WATCHPOINT_ASSERT(error == 0);
+    (void)(error);
+    assert(error == 0);
   }
 
 #ifdef TCP_KEEPIDLE
   if (server->root->tcp_keepidle > 0)
   {
-    int error;
-
-    error= setsockopt(server->fd, IPPROTO_TCP, TCP_KEEPIDLE,
-                      &server->root->tcp_keepidle, (socklen_t)sizeof(int));
-    WATCHPOINT_ASSERT(error == 0);
+    int error= setsockopt(server->fd, IPPROTO_TCP, TCP_KEEPIDLE,
+                          &server->root->tcp_keepidle, (socklen_t)sizeof(int));
+    (void)(error);
+    assert(error == 0);
   }
 #endif
 
   if (server->root->send_size > 0)
   {
-    int error;
-
-    error= setsockopt(server->fd, SOL_SOCKET, SO_SNDBUF,
-                      &server->root->send_size, (socklen_t)sizeof(int));
-    WATCHPOINT_ASSERT(error == 0);
+    int error= setsockopt(server->fd, SOL_SOCKET, SO_SNDBUF,
+                          &server->root->send_size, (socklen_t)sizeof(int));
+    (void)(error);
+    assert(error == 0);
   }
 
   if (server->root->recv_size > 0)
   {
-    int error;
-
-    error= setsockopt(server->fd, SOL_SOCKET, SO_RCVBUF,
-                      &server->root->recv_size, (socklen_t)sizeof(int));
-    WATCHPOINT_ASSERT(error == 0);
+    int error= setsockopt(server->fd, SOL_SOCKET, SO_RCVBUF,
+                          &server->root->recv_size, (socklen_t)sizeof(int));
+    (void)(error);
+    assert(error == 0);
   }
 
-
   /* libmemcached will always use nonblocking IO to avoid write deadlocks */
   set_socket_nonblocking(server);
 }
 
-static memcached_return_t unix_socket_connect(memcached_server_st *server)
+static memcached_return_t unix_socket_connect(org::libmemcached::Instance* server)
 {
 #ifndef WIN32
-  WATCHPOINT_ASSERT(server->fd == -1);
+  WATCHPOINT_ASSERT(server->fd == INVALID_SOCKET);
+
+  int type= SOCK_STREAM;
+  if (SOCK_CLOEXEC)
+  {
+    type|= SOCK_CLOEXEC;
+  }
 
-  if ((server->fd= socket(AF_UNIX, SOCK_STREAM, 0)) < 0)
+  if (SOCK_NONBLOCK)
+  {
+    type|= SOCK_NONBLOCK;
+  }
+
+  if ((server->fd= socket(AF_UNIX, type, 0)) < 0)
   {
     memcached_set_errno(*server, errno, NULL);
     return MEMCACHED_CONNECTION_FAILURE;
@@ -369,7 +441,7 @@ static memcached_return_t unix_socket_connect(memcached_server_st *server)
 
       case EISCONN: /* We were spinning waiting on connect */
         {
-          WATCHPOINT_ASSERT(0); // Programmer error
+          assert(0); // Programmer error
           break;
         }
 
@@ -391,56 +463,75 @@ static memcached_return_t unix_socket_connect(memcached_server_st *server)
 #endif
 }
 
-static memcached_return_t network_connect(memcached_server_st *server)
+static memcached_return_t network_connect(org::libmemcached::Instance* server)
 {
   bool timeout_error_occured= false;
 
   WATCHPOINT_ASSERT(server->fd == INVALID_SOCKET);
-  WATCHPOINT_ASSERT(server->cursor_active == 0);
+  WATCHPOINT_ASSERT(server->cursor_active_ == 0);
 
-  if (not server->address_info)
+  /*
+    We want to check both of these because if address_info_next has been fully tried, we want to do a new lookup to make sure we have picked up on any new DNS information.
+  */
+  if (server->address_info == NULL or server->address_info_next == NULL)
   {
     WATCHPOINT_ASSERT(server->state == MEMCACHED_SERVER_STATE_NEW);
-    memcached_return_t rc;
-    uint32_t counter= 5;
-    while (--counter)
-    {
-      if ((rc= set_hostinfo(server)) != MEMCACHED_TIMEOUT)
-      {
-        break;
-      }
-
-#ifndef WIN32
-      struct timespec dream, rem;
-
-      dream.tv_nsec= 1000;
-      dream.tv_sec= 0;
-
-      nanosleep(&dream, &rem);
-#endif
-    }
+    server->address_info_next= NULL;
+    memcached_return_t rc= set_hostinfo(server);
 
     if (memcached_failed(rc))
+    {
       return rc;
+    }
+  }
+
+  if (server->address_info_next == NULL)
+  {
+    server->address_info_next= server->address_info;
+    server->state= MEMCACHED_SERVER_STATE_ADDRINFO;
   }
 
   /* Create the socket */
-  while (server->address_info_next && server->fd == INVALID_SOCKET)
+  while (server->address_info_next and server->fd == INVALID_SOCKET)
   {
     /* Memcache server does not support IPV6 in udp mode, so skip if not ipv4 */
-    if (server->type == MEMCACHED_CONNECTION_UDP && server->address_info_next->ai_family != AF_INET)
+    if (memcached_is_udp(server->root) and server->address_info_next->ai_family != AF_INET)
     {
       server->address_info_next= server->address_info_next->ai_next;
       continue;
     }
 
+    int type= server->address_info_next->ai_socktype;
+    if (SOCK_CLOEXEC)
+    {
+      type|= SOCK_CLOEXEC;
+    }
+
+    if (SOCK_NONBLOCK)
+    {
+      type|= SOCK_NONBLOCK;
+    }
+
     if ((server->fd= socket(server->address_info_next->ai_family,
-                            server->address_info_next->ai_socktype,
+                            type,
                             server->address_info_next->ai_protocol)) < 0)
     {
       return memcached_set_errno(*server, get_socket_errno(), NULL);
     }
 
+    // If SOCK_CLOEXEC exists then we don't need to call the following
+    if (SOCK_CLOEXEC == 0)
+    {
+      if (FD_CLOEXEC)
+      {
+        int rval;
+        do
+        {
+          rval= fcntl (server->fd, F_SETFD, FD_CLOEXEC);
+        } while (rval == -1 && (errno == EINTR or errno == EAGAIN));
+      }
+    }
+
     set_socket_options(server);
 
     /* connect to server */
@@ -457,7 +548,10 @@ static memcached_return_t network_connect(memcached_server_st *server)
       timeout_error_occured= true;
       break;
 
+    case EAGAIN:
+#if EWOULDBLOCK != EAGAIN
     case EWOULDBLOCK:
+#endif
     case EINPROGRESS: // nonblocking mode - first return
     case EALREADY: // nonblocking mode - subsequent returns
       {
@@ -510,20 +604,10 @@ static memcached_return_t network_connect(memcached_server_st *server)
   }
 
   WATCHPOINT_STRING("Never got a good file descriptor");
-  /* Failed to connect. schedule next retry */
-  if (server->root->retry_timeout)
-  {
-    struct timeval next_time;
-
-    if (gettimeofday(&next_time, NULL) == 0)
-    {
-      server->next_retry= next_time.tv_sec + server->root->retry_timeout;
-    }
-  }
 
   if (memcached_has_current_error(*server))
   {
-    return memcached_server_error_return(server);
+    return memcached_instance_error_return(server);
   }
 
   if (timeout_error_occured and server->state < MEMCACHED_SERVER_STATE_IN_PROGRESS)
@@ -534,58 +618,106 @@ static memcached_return_t network_connect(memcached_server_st *server)
   return memcached_set_error(*server, MEMCACHED_CONNECTION_FAILURE, MEMCACHED_AT); /* The last error should be from connect() */
 }
 
-void set_last_disconnected_host(memcached_server_write_instance_st self)
-{
-  // const_cast
-  memcached_st *root= (memcached_st *)self->root;
 
-  memcached_server_free(root->last_disconnected_server);
-  root->last_disconnected_server= memcached_server_clone(NULL, self);
-}
+/*
+  backoff_handling()
 
-memcached_return_t memcached_connect(memcached_server_write_instance_st server)
+  Based on time/failure count fail the connect without trying. This prevents waiting in a state where
+  we get caught spending cycles just waiting.
+*/
+static memcached_return_t backoff_handling(org::libmemcached::Instance* server, bool& in_timeout)
 {
-  memcached_return_t rc= MEMCACHED_NO_SERVERS;
+  struct timeval curr_time;
+  bool _gettime_success= (gettimeofday(&curr_time, NULL) == 0);
 
-  if (server->fd != INVALID_SOCKET)
+  /* 
+    If we hit server_failure_limit then something is completely wrong about the server.
+
+    1) If autoeject is enabled we do that.
+    2) If not? We go into timeout again, there is much else to do :(
+  */
+  if (server->server_failure_counter >= server->root->server_failure_limit)
   {
-    return MEMCACHED_SUCCESS;
-  }
+    /*
+      We just auto_eject if we hit this point 
+    */
+    if (_is_auto_eject_host(server->root))
+    {
+      set_last_disconnected_host(server);
 
-  LIBMEMCACHED_MEMCACHED_CONNECT_START();
+      // Retry dead servers if requested
+      if (_gettime_success and server->root->dead_timeout > 0)
+      {
+        server->next_retry= curr_time.tv_sec +server->root->dead_timeout;
 
-  /* both retry_timeout and server_failure_limit must be set in order to delay retrying a server on error. */
-  WATCHPOINT_ASSERT(server->root);
-  if (server->root->retry_timeout and server->next_retry)
-  {
-    struct timeval curr_time;
+        // We only retry dead servers once before assuming failure again
+        server->server_failure_counter= server->root->server_failure_limit -1;
+      }
+
+      memcached_return_t rc;
+      if (memcached_failed(rc= run_distribution((memcached_st *)server->root)))
+      {
+        return memcached_set_error(*server, rc, MEMCACHED_AT, memcached_literal_param("Backoff handling failed during run_distribution"));
+      }
 
-    gettimeofday(&curr_time, NULL);
+      return memcached_set_error(*server, MEMCACHED_SERVER_MARKED_DEAD, MEMCACHED_AT);
+    }
 
-    // We should optimize this to remove the allocation if the server was
-    // the last server to die
-    if (server->next_retry > curr_time.tv_sec)
+    server->state= MEMCACHED_SERVER_STATE_IN_TIMEOUT;
+
+    // Sanity check/setting
+    if (server->next_retry == 0)
     {
-      set_last_disconnected_host(server);
+      server->next_retry= 1;
+    }
+  }
 
-      return memcached_set_error(*server, MEMCACHED_SERVER_MARKED_DEAD, MEMCACHED_AT);
+  if (server->state == MEMCACHED_SERVER_STATE_IN_TIMEOUT)
+  {
+    /*
+      If next_retry is less then our current time, then we reset and try everything again.
+    */
+    if (_gettime_success and server->next_retry < curr_time.tv_sec)
+    {
+      server->state= MEMCACHED_SERVER_STATE_NEW;
+    }
+    else
+    {
+      return memcached_set_error(*server, MEMCACHED_SERVER_TEMPORARILY_DISABLED, MEMCACHED_AT);
     }
+
+    in_timeout= true;
+  }
+
+  return MEMCACHED_SUCCESS;
+}
+
+static memcached_return_t _memcached_connect(org::libmemcached::Instance* server, const bool set_last_disconnected)
+{
+  assert(server);
+  if (server->fd != INVALID_SOCKET)
+  {
+    return MEMCACHED_SUCCESS;
   }
 
-  // If we are over the counter failure, we just fail. Reject host only
-  // works if you have a set number of failures.
-  if (server->root->server_failure_limit and server->server_failure_counter >= server->root->server_failure_limit)
+  LIBMEMCACHED_MEMCACHED_CONNECT_START();
+
+  bool in_timeout= false;
+  memcached_return_t rc;
+  if (memcached_failed(rc= backoff_handling(server, in_timeout)))
   {
     set_last_disconnected_host(server);
+    return rc;
+  }
 
-    // @todo fix this by fixing behavior to no longer make use of
-    // memcached_st
-    if (_is_auto_eject_host(server->root))
-    {
-      run_distribution((memcached_st *)server->root);
-    }
+  if (LIBMEMCACHED_WITH_SASL_SUPPORT and server->root->sasl.callbacks and memcached_is_udp(server->root))
+  {
+    return memcached_set_error(*server, MEMCACHED_INVALID_HOST_PROTOCOL, MEMCACHED_AT, memcached_literal_param("SASL is not supported for UDP connections"));
+  }
 
-    return memcached_set_error(*server, MEMCACHED_SERVER_MARKED_DEAD, MEMCACHED_AT);
+  if (server->hostname[0] == '/')
+  {
+    server->type= MEMCACHED_CONNECTION_UNIX_SOCKET;
   }
 
   /* We need to clean up the multi startup piece */
@@ -594,6 +726,7 @@ memcached_return_t memcached_connect(memcached_server_write_instance_st server)
   case MEMCACHED_CONNECTION_UDP:
   case MEMCACHED_CONNECTION_TCP:
     rc= network_connect(server);
+
     if (LIBMEMCACHED_WITH_SASL_SUPPORT)
     {
       if (server->fd != INVALID_SOCKET and server->root->sasl.callbacks)
@@ -616,22 +749,48 @@ memcached_return_t memcached_connect(memcached_server_write_instance_st server)
 
   if (memcached_success(rc))
   {
-    server->server_failure_counter= 0;
-    server->next_retry= 0;
+    server->mark_server_as_clean();
+    memcached_version_instance(server);
+    return rc;
   }
-  else if (memcached_has_current_error(*server))
+  else if (set_last_disconnected)
   {
-    server->server_failure_counter++;
     set_last_disconnected_host(server);
+    if (memcached_has_current_error(*server))
+    {
+      memcached_mark_server_for_timeout(server);
+      assert(memcached_failed(memcached_instance_error_return(server)));
+    }
+    else
+    {
+      memcached_set_error(*server, rc, MEMCACHED_AT);
+      memcached_mark_server_for_timeout(server);
+    }
+
+    LIBMEMCACHED_MEMCACHED_CONNECT_END();
+
+    if (in_timeout)
+    {
+      char buffer[1024];
+      int snprintf_length= snprintf(buffer, sizeof(buffer), "%s:%d", server->hostname, int(server->port()));
+      return memcached_set_error(*server, MEMCACHED_SERVER_TEMPORARILY_DISABLED, MEMCACHED_AT, buffer, snprintf_length);
+    }
   }
-  else
+
+  return rc;
+}
+
+memcached_return_t memcached_connect_try(org::libmemcached::Instance* server)
+{
+  if (server and server->root and server->root->state.is_parsing)
   {
-    memcached_set_error(*server, rc, MEMCACHED_AT);
-    server->server_failure_counter++;
-    set_last_disconnected_host(server);
+    return MEMCACHED_SUCCESS;
   }
 
-  LIBMEMCACHED_MEMCACHED_CONNECT_END();
+  return _memcached_connect(server, false);
+}
 
-  return rc;
+memcached_return_t memcached_connect(org::libmemcached::Instance* server)
+{
+  return _memcached_connect(server, true);
 }