On Tue, 2007-07-24 at 20:56 +0200, Sergei Golubchik wrote:
> Hi!
>
> On Jul 24, Antony T Curtis wrote:
> > On Tue, 2007-07-24 at 19:15 +0200, Sergei Golubchik wrote:
> > > On Jul 09, antony@stripped wrote:
> > > > ChangeSet@stripped, 2007-07-09 21:54:16-07:00, antony@stripped +4 -0
> > > > Bug#25679
> > > > "Federated Denial of Service"
> > > > Federated storage engine used to attempt to open connections
> within
> > > > the ::create() and ::open() methods which are invoked while
> LOCK_open
> > > > mutex is being held by mysqld. As a result, no other connection
> can
> > > > open tables during the network processing. Long DNS lookup times
> > > > would stall mysqld's operation and a rogue connection string
> which
> > > > connects to a remote server which simply stalls during handshake
> can
> > > > stall mysqld for much longer periods of time.
> > > > This patch moves the connection-opening much later to when
> LOCK_open
> > > > mutex is not being held.
> > >
> > > > diff -Nrup a/sql/ha_federated.cc b/sql/ha_federated.cc
> > > > --- a/sql/ha_federated.cc 2007-06-29 15:14:00 -07:00
> > > > +++ b/sql/ha_federated.cc 2007-07-09 21:54:03 -07:00
> > > ....
> > > > + if (!mysql_real_connect(mysql,
> > > > + share->hostname,
> > > > + share->username,
> > > > + share->password,
> > > > + share->database,
> > > > + share->port,
> > > > + share->socket, 0))
> > > > + {
> > > > + mysql_close(mysql);
> > > > + mysql= NULL;
> > > > + sql_query.append("database: '");
> > > > + sql_query.append(share->database);
> > > > + sql_query.append("' username: '");
> > > > + sql_query.append(share->username);
> > > > + sql_query.append("' hostname: '");
> > > > + sql_query.append(share->hostname);
> > > > + sql_query.append("'");
> > > > + my_error(ER_CONNECT_TO_FOREIGN_DATA_SOURCE, MYF(0),
> sql_query.ptr());
> > > > + remote_error_number= -1;
> > >
> > > Why you don't use stash_remote_error(), but generates less informative
> > > generic error message ?
> >
> > Using same error message as it used to generate in case where connection
> > has failed.
>
> But there was stash_remote_error() in ha_federated::open() before.
Hmm... looks like I copied this out from the connection test code which
was used by create()
I will correct this in the updated patch.
Regards,
--
Antony T Curtis, Senior Software Developer
MySQL Inc, www.mysql.com
SIP: 4468@stripped
