Yes, I have tested that.
My test results seem to tally up with what I could read here
http://dev.mysql.com/doc/refman/5.0/en/auto-reconnect.html
Code below was used. I restarted the server at every 30s sleep() I have
in the below code.
If you follow the same but with the "SET @@session..." lines other than
the first set commented out; the sequence generated in the table is 1 2
3, where as the expected sequence is 1 3 5
Here MySQL version is 5.0.75
--------------------------8<----------------------------
#include <mysql++.h>
#include <string>
#include <iostream>
int main() {
mysqlpp::Connection conn(true);
conn.set_option(new mysqlpp::ReconnectOption(true));
if(!conn.connect("test_purge", "localhost", "root")) {
std::cerr << "db connection failed - " << conn.error() << std::endl;
return 1;
}
conn.query("SET @@session.AUTO_INCREMENT_INCREMENT = 2").execute();
conn.query("SET @@session.AUTO_INCREMENT_OFFSET = 1").execute();
conn.query("INSERT INTO auto_inc () VALUES ()").execute();
std::cout << "========================" << std::endl;
sleep(30);
conn.query("SET @@session.AUTO_INCREMENT_INCREMENT = 2").execute();
conn.query("SET @@session.AUTO_INCREMENT_OFFSET = 1").execute();
conn.query("INSERT INTO auto_inc () VALUES ()").execute();
std::cout << "========================" << std::endl;
sleep(30);
conn.query("SET @@session.AUTO_INCREMENT_INCREMENT = 2").execute();
conn.query("SET @@session.AUTO_INCREMENT_OFFSET = 1").execute();
conn.query("INSERT INTO auto_inc () VALUES ()").execute();
}
-------------------8<-------------------
CREATE TABLE `auto_inc` (
`id` int(11) NOT NULL auto_increment,
PRIMARY KEY (`id`)
) ENGINE=MyISAM
Warren Young wrote:
> Dino Korah wrote:
>> reconnect -> re-initialise-connection -> do-processing.
>
> Are you certain you need to re-send the connection setup SQL commands
> after reconnection? The whole point of automatic reconnection is that
> the connection should be put back in the same state it was in before it
> was dropped. I don't know one way or the other; have you tested it?
>
> If that doesn't happen, then I would suggest using periodic
> Connection::ping() calls instead of ReconnectOption. When ping() fails,
> reconnect and reinit. You also have to check query failure if you go
> down this path, however, because the DB server could go away in between
> a ping() success and the Query::execute()/store()/use() call.
