MySQL Bugs: #36225: Connect time out not using values that are set

Bug #36225	Connect time out not using values that are set
Submitted:	21 Apr 2008 6:30	Modified:	16 Apr 2013 15:05
Reporter:	Michael Ryan	Email Updates:
Status:	Verified	Impact on me:	None
Category:	MySQL Server: C API (client library)	Severity:	S2 (Serious)
Version:	5.0.46, 5.0.54a, 5.1.23	OS:	Windows (Windows XP)
Assigned to:		CPU Architecture:	Any
Tags:	connect_timeout, MYSQL_OPT_CONNECT_TIMEOUT

Description:
I have a client program which is attempting to connect to a remote host that has been powered down due to failure. I have used ADISetOptions() with the MYSQL_OPT_CONNECT_TIMEOUT option and also I have set the value directory in the MYSQL structure for connect_timeout but it is not being used. Instead of timing the connection attempt out after X seconds, it always takes between 21 and 23 seconds. My client program is running on Windows XP and the remote machine is also Windows XP. This is not a firewall related issue as I have shut down the firewall and there was no difference in the time taken to fail the connection attempt.

How to repeat:
This is the test code I have created to make a repeatable test (I link with lib\opt\mysqlient.lib and I use MS VS2005).

#include <windows.h>
#include <process.h>
#include <stdio.h>
#include <stdlib.h>
#include <mysql.h>
#include <time.h>

#define CONVERT_TO_MS_DOUBLE(start, stop, ticksInSec) ((double)((stop).QuadPart - (start).QuadPart) / (ticksInSec).QuadPart) * 1000

int main(int argc, char **argv)
{
	MYSQL *myData;
   LARGE_INTEGER startTime, stopTime, ticksInSec;

   QueryPerformanceFrequency(&ticksInSec);

   QueryPerformanceCounter(&startTime);
	
	myData = mysql_init((MYSQL*) 0);
	myData->options.connect_timeout = 1;

	if (!mysql_real_connect(myData, "192.168.1.190", "adb_user", "adb", "adb", 3306, NULL, 0))
		printf("Error: %s\n", mysql_error(myData));
	else
		mysql_close( myData ) ;

   QueryPerformanceCounter(&stopTime);

	printf("Time in millisecs was %f\n", CONVERT_TO_MS_DOUBLE(startTime, stopTime, ticksInSec));

	return 0;
}

Thank you for the report.

Verified as described. Bug is repeatable only on Windows.

Is there any progress on this bug ? It was verified as a bug nearly 4 months ago and there has been no further update. I do not use the community edition. I actually paid for MySQL licenses so expected the feedback and response to be a little better than what it has been. The software I am writing is due to go live in a couple of months and this is still a major issue !

Thank you for the feedback.

> I actually paid for MySQL licenses so expected the feedback and response to be a little better than what it has been.

I am sorry, but bug database is only for discussions related to bug reports itself, not for usage. If you need feedback please open support issue.

> I am sorry, but bug database is only for discussions related to bug reports itself, not for usage. If you need feedback please open support issue.

Feedback to bugs corrected should be done through the bug database. I did not expect nor ask for feedback to me personally but feedback about the bug in the bug database. This should not need to be a support request seeing it is a bug and I simply want the bug report updated with progress (i.e. when will this bug be fixed).

Bug #41911 was marked as duplicate of this one.

I have written a patch that works for me. Maybe someone wants to review it and commit.

--- client.c.org	Fri Jun 03 12:25:45 2011
+++ client.c	Fri Jun 03 12:20:58 2011
@@ -129,6 +129,10 @@
 static int wait_for_data(my_socket fd, uint timeout);
 #endif
 
+#if defined(__WIN__) 
+static int is_socket_connected(int fd, fd_set *rd, fd_set *wr, fd_set *ex);
+#endif
+
 CHARSET_INFO *default_client_charset_info = &my_charset_latin1;
 
 /* Server error code and message */
@@ -147,8 +151,51 @@
 int my_connect(my_socket fd, const struct sockaddr *name, uint namelen,
 	       uint timeout)
 {
-#if defined(__WIN__) || defined(__NETWARE__)
+#if defined(__NETWARE__)
   return connect(fd, (struct sockaddr*) name, namelen);
+#elif defined(__WIN__)
+  int ret;
+  
+  // Set the socket to Non-blocking mode
+  int NonBlk = 1;  
+  ioctlsocket(fd, FIONBIO, &NonBlk);
+      
+  ret = connect(fd, (struct sockaddr*) name, namelen);
+  
+  // If connected, it will return 0, else it will return an error code
+  if (ret == SOCKET_ERROR)
+  {
+    ret = WSAGetLastError();
+    // Check if the error was WSAEWOULDBLOCK, where we'll wait.
+    if (ret == WSAEWOULDBLOCK)
+    {      
+      fd_set rd, wr, err;
+      struct timeval tv;
+
+      FD_ZERO(&rd);      
+      FD_SET(fd, &rd);
+      wr = rd;
+      err = rd;
+
+      // Set the timeout
+      tv.tv_sec  = timeout;
+      tv.tv_usec = 0;
+
+      ret = select (0, &rd, &wr, &err, &tv);
+      if ( ret == SOCKET_ERROR )
+        return(-1); /* select failed */		
+	    else if ( ret == 0 )
+        return(-1); /* select timeout */		    
+	    else if( is_socket_connected(fd, &rd, &wr, &err) )
+	      return(0);			
+	    else
+        return(-1);
+    }
+  }
+  else 
+    return(0);  /* Connect with no waiting! */
+
+  return(-1);    
 #else
   int flags, res, s_err;
 
@@ -179,6 +226,24 @@
 #endif
 }
 
+/*
+  Check socket status. Code taken from Effective TCP/IP Programming, 
+  by Jon Snader.
+*/
+#if defined(__WIN__)
+int is_socket_connected(int fd, fd_set *rd, fd_set *wr, fd_set *ex)
+{  
+  WSASetLastError(0);
+
+  if (!FD_ISSET(fd, rd) && !FD_ISSET(fd, wr))  
+    return(0);
+
+  if (FD_ISSET(fd, ex))  
+    return(0);  
+    
+  return(1);
+}
+#endif /*__WIN__*/
 
 /*
   Wait up to timeout seconds for a connection to be established.
@@ -278,7 +343,7 @@
   return (0);					/* ok */
 #endif /* HAVE_POLL */
 }
-#endif /* defined(__WIN__) || defined(__NETWARE__) */
+#endif /* !defined(__WIN__) || defined(__NETWARE__) */
 
 /**
   Set the internal error message to mysql handler

This issue was addressed by the patch for Bug#54790.

Reproduced this problem on MySQL 5.1 and 5.5.
5.6 is not affected.