Idézet (Emmanuel Lecharny <[email protected]>):
On 7/7/10 1:49 PM, [email protected] wrote:
Hi,
we are developing a client/server application, where the
server-side uses MINA as its communication framework. On the top of
the filter chain there is a message handler class that extends
IoHandlerAdapter.
The message handler does some business logic, that is executed in
transactional context using Spring Framework's declarative
transaction management. After the method implementing the business
logic executed and returns the response message, the transaction is
committed and the response is sent back to the client.
The problem is when the client is disconnected during executing the
transactional method (network problems, etc.) In this scenario the
transaction is committed and the server detects the lost connection
only when it tries to send out the response message. In our case
the transaction should be rolled back.
Can you suggest some way how to detect the connection failure
earlier than sending out the message?
There is no way to detect a connection failure. The connection is
opened or closed, but you will know only after having successfully
sent something to the client.
In other words, you have to implement a kind of two-phases commit in
your case :
- receive the request
- make your business transaction
- send the response to the client (at this point, the business
transaction is supposed to have been sucessful)
- when the message has been sent, commit the business transaction.
I was afraid of this answer :) Probably we'll need to move from
declarative to programmatic transaction handling.
However, even if the response has been sent, you have no way to be
sure that your client has read it.
Yes, I'm aware of this, but in our practice it is far more common that
a client disconnects during the execution of the business function
which can take from few seconds up to few minutes, than disconnecting
while sending the response, that can be measured in tenths of seconds
or less.
Remember that you are dealing with remote communications, where one
of the peer may perfectly disconnect without notice, and you have to
deal with this at the protocol level. MINA won't help you here.
Okay, thank you for your response!
Regards,
Andras
We are using Mina 1.1.7.
Regards,
Andras
--
Regards,
Cordialement,
Emmanuel Lécharny
www.iktek.com
