Re: Connectivity problem (?), mysql_ping ()

[Lefteris Tsintjelis]

Hi again,

This is intresting, the documentation indeed mentions that mysql_ping
indicates "Zero if the connection to the server is alive" and not that
"zero if the server is alive", as I *naturally expected* also, so it
is kind of tricky this one. I would expect the same behavior with Unix
sockets or TCP sockets though. By restarting the server the connection
breaks so I guess the first ping restores that broken connection and
therefor returns with a non zero value since the connection was not
alive at that moment.

However, since reconnect was set, I would *_very_ naturally expect* to
try and reconnect first and then return with a 0 value if everything is
OK. This would definetly make much more sence and make mysql_ping ()
much easier to use, instead of now making an extra mysql_ping () again
to see if the first one restored the connection or not...

(I will also add those comments to your report)

Regards,

Lefteris

Gleb Paharenko wrote:
> Hello.
> 
> I've found that mysql_ping doesn't work properly with TCP connection (in
> your test case you put the hostname to "127.0.0.1"). My program was
> working with "localhost" - connection through the Unix socket. You may
> want to add you comments to my bug report at:
>   http://bugs.mysql.com/bug.php?id=14057
> 
> 
> 
> 
> Lefteris Tsintjelis wrote:
> 
>>I did some extensive testing and it looks like that only the first
>>mysql_ping () fails to reconnect or very possibly returns the wrong
>>result. I am currently using v4.1.14.
>>
>>Regards,
>>
>>Lefteris
>>
>>----------------------------------------------------
>>Begin
>>MySQL is up and running
>>Restart MySQL and hit enter (reconnect: 1)...
>>
>>Error: Lost connection to MySQL server during query
>>Ping 2 Ok!
>>Ping 3 Ok!
>>----------------------------------------------------
>>#include <stdio.h>
>>#include <mysql.h>
>>
>>int main ()
>>{
>>        int i;
>>        char c;
>>        MYSQL mysql;
>>
>>        fprintf (stdout, "Begin\n");
>>        mysql_init (&mysql);
>>        if (!mysql_real_connect (&mysql, "127.0.0.1", "root", "",
>>"test", 0, NULL, 0))
>>                fprintf (stderr, "Failed to connect to database: Error:
>>%s\n", mysql_error (&mysql));
>>        else
>>                fprintf (stdout, "MySQL is up and running\n");
>>        mysql.reconnect = 1;
>>        fprintf (stdout, "Restart MySQL and hit enter (reconnect:
>>%d)...", mysql.reconnect);
>>        c = getchar ();
>>        (void) putc ('\n', stdout);
>>        for (i = 1; i < 4; i++)
>>                if (mysql_ping (&mysql))
>>                        fprintf (stderr, "Error: %s\n",
>>mysql_error(&mysql));
>>                else
>>                        fprintf (stdout, "Ping %d Ok!\n", i);
>>        return (0);
>>}
>>
> 
> 
>