Java IBM MQ Client connected but not getting messages from queue

Question

I have a Camel/Spring-based Java MQ client, which should connect to MQ and get some messages from queue. The connection is estabilished, but the client is not downloading any messages. Wireshark network analysis shows that after some initial processing an MQCLOSE is generated and only further only heartbeat traffic appears.

The IBM MQ server version is 8.0.0.5 while the client JARs are in version 7.1.0.3. But I believe this combination worked on other environments.

I have checked the application on some other environment, where it works properly and after the MQCLOSE_REPLY there comes a number of other messages, starting with what Wireshark recognizes as SOCKET_ACTION. But this does not happen on this environment, why??

Answer 1

Your application isn't requesting any messages, that's why it is not receiving any.

Based on the snippet of network trace from your non-working environment, it is only connecting (opening, inquiring and closing the queue manager - which it does during connection processing and after the MQCONN). The connection that was created is then not used - there are no MQGET or SPI flows, just heartbeats.

Why are you trying to debug this using network packet trace anyway?!

Look at the application and work out what it does after connecting and determine why it isn't requesting any messages.

Answer 2

a_cornish_pasty was right - the application was not requesting any messages. And that's because the Camel route has not been started properly due to some startup error I missed.