Actually all the code up to executeQuery did not require a db connection,
so it only tried to get the db connection when that statement was reached.

I just committed a change that gets a db connection when a
ManagedConnection is created: this will be when not enough are pooled to
satisfy a request for a Connection.

I think your investigations pretty clearly show that for some reason you
aren't able to connect to the server. I'd start by adding a log statement
so you can see the IOException. Hopefully this will give a clue- this
should be logged anyway-- I'll add it to cvs.

Are all the connections for the same user, password, and other properties?

Thanks
david jencks

On 2002.03.21 13:02:35 -0500 Mandip S. Sangha wrote:
> Hi David
>
> The code being executed for every query is:
>
> Class.forName (driverClass).newInstance();
> connection = DriverManager.getConnection (url,properties);
> statement = connection.createStatement();
> (1)
> (2)
> resultSet = statement.executeQuery(sqlString);
>
> resultSet.close();
> resultSet = null;
>
> statement.close();
> statement = null;
>
> connection.close();
> connection = null;
>
> I've got a sys.out at point (1) that checks:
> a) Whether the connection is null.
> b) Whether the connection is closed.
> BOTH RETURN FALSE even when the error in question is thrown!
>
> When the error is thrown the code fails at point (2), as far as I can
> see(from the above checks) the connection and statement are fine up to
> this point
>
> Therefore, am I correct in assuming that the error cannot be thrown
> because we "can't get a connection" or the "connection died and the
> driver didn't notice".
>
> If not please can you tell me how to check the connection really is
> valid and is open.
>
> Otherwise that leaves the possibility of "the server dying", if I've
> understood correctly what you mean by this then this is not an issue
> since there has never been an instance where the error has actually
> crashed/stopped/shutdown the database server. Also the database server
> that I connect to is running locally eliminating any problems that could
> be caused by sending things over the wire.
>
> This leads me back to the error:
>
> [GDS_Impl,DEBUG] Got socket
> [GDS_Impl,DEBUG] user.name: mandip
> [GDS_Impl,DEBUG] op_connect
> [GDS_Impl,DEBUG] sent
> [GDS_Impl,DEBUG] op_accept
> [FBManagedConnectionFactory,ERROR] GDS Exception in getDbHandle
> org.firebirdsql.gds.GDSException: unable to complete network request to
> host
> at org.firebirdsql.jgds.GDS_Impl.connect(GDS_Impl.java:1304)
>
> Looking at the connect method in the GDS_Impl class we see:
>
> :
> :
> db.out.writeInt(3); // ptype_batch_send
> db.out.writeInt(2);
> db.out.flush();
> if (log.isDebugEnabled()) {log.debug("sent");}
> (1)
> if (log.isDebugEnabled()) {log.debug("op_accept ");}
> (2)
> if (readOperation(db) == op_accept) {
> db.in.readInt(); // Protocol version number
> db.in.readInt(); // Architecture for protocol
> db.in.readInt(); // Minimum type
> if (log.isDebugEnabled()) {log.debug("received");}
> }
> (3)
> else {
> disconnect(db);
> if (log.isDebugEnabled()) {log.debug("not received");}
> throw new GDSException(isc_connect_reject);
> }
> } catch (IOException ex) {
> throw new GDSException(isc_network_error);
> }
>
> Everthing executes fine up to point (1) as reflected by the log message,
> but after this things become unclear, can we determine at exactly what
> point the exception is thrown?
>
> Again your comments/suggestions would be greatly appreciated. :-)
>
> Regards
> Mandip
>
>
>
>
>
> David Jencks wrote:
>
> > Either you can't get a connection due to misconfiguration or the server
> > dying or a connection died and the driver didn't notice. Due to
> adapting
> > firebird to xa semantics the driver doesn't actually make a connection
> > until it knows what transaction you are working in.
> >
> > Do some of your tests succeed?
> > Does some test before the one that fails in this way do something that
> > might break the connection?
> > If you are using the built in pooling, try turning it off and see what
> > happens: if you aren't, you might try turning it on;-)
> >
> > david jencks
>
>
>
>
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