RE: Connection Error [-708] Could not send data

[Alexander Schroeder]

Hello Robert,

could you retrieve the specific driver version (I'm quite sure, but to be safe,
tell me what 'java -jar sapdbc.jar -V' did print out).


> Statement stmt = conn.createStatement();
> ...
> stmt.executeQuery("SELECT * FROM check_table WHERE 1 = 2").close();
> 
> Now, *if* the connection did timeout, then this line should trigger an
> exception and the connection is never returned from the pool 
> but instead
> discarded.  If there is no valid connection in the pool, a new one is
> created.  But why then would the new connection throw this 
> exception, as it
> was just (i.e. n seconds ago with n < timeout) created?
> 
> Also, our code has a level of fault tolerance: we're using prepared
> statements and if an execution fails, the prepared statement 
> is closed, the
> connection dropped and a new connection is obtained.  Then a new PS is
> created etc.  Strangely enough the second attempt (with the 
> new conn) yields
> the same error as the first attempt.  How can it be that a 
> new connection
> has this problem?  

This all together tells that it is probably not a timeout itself, but 
a network error in the resolution of a timeout error. The stack backtrace
comes from the CONNECT statement of the 'silent' reconnect, *but* this
statement is not the first packet sent to the server ...

> Is there some pooling of physical connections done
> internally in the driver?

No.

Regards
Alexander Schröder