Durable subscriptions and windows clients

Question

Hi,
I think I have found a potential problem.
Scenario
MQ: 3.x or 4.x
Clients: windows OS with Durable Subscriptions
Destinations: Topic
Problem:
Disconnect a windows client with a durable subscription (for example, pulling the network cable)
Try to reconnect, and you will get "Client ID already in use". Under unix, this happens only for a few secs and that's fine. Under Windows, you won't be able to reconnect for almost 10 minutes. That means that a windows client can't easily reconnect if it uses a durable subscription, and has to wait the server killing its socket.
The problem seems that the server socket stays ESTABLISHED (just do a netstat -an | grep -i ESTABLISHED on the server) for a longer time when the client is windows. So that is a windows socket problem (I just tried with a Simpel TCP Server and that's the same), but I think a JMS server should circumvent it
Possible solutions:
- MQ client overriding the connection if a client id is already in use AND the connection comes from the same IP. I think that should be the default!
- a configurable heartbeat between client and server
- Something like "imqcmd deactivate dur" could do the job. I haven't found a way to manually DISACTIVATE the connect, but only to destroy it (imqcmd destroy dur), which obviously isn't a viable option (possible msg loss)
- Java API to do the same thing
ciao,
uL

Answer 1

I think that the problem may be with the TTL on the sockets. Basically as far as I know unless there is a traffic on the connection there is no way to detect that the other end of a socket connection is gone. You may try enabling ping on the connection this may speed things up.
Tom