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From Kuppe <>
Subject Connection questions
Date Thu, 22 Jun 2006 10:47:19 GMT

Hi guys,

hopefullly a simple one for you. i am using ActiveMQ RC2 to create a broker
and multiple pub/sub clients.

for the clients i use failover(tcp:) transport and on the broker i use the
default broker configuration without persistence. I create all client
connections using the createConnection() method of the
ActiveMqConnectionFactory which has prefetch policy defined and asynch send
and dispatch set. No other methods are called on the connection or factory
for configuration. Specifically i do not explicitly set a client id.

i notice the following symptom - some clients enter into an endless
reconnect loop whilst establishing connections to the broker (actually many
clients, and more regularly when connecting through a proxy server). on the
broker i notice exceptions from inactivity monitor showing no activity, but
nothing explicit regarding the specific client.

After scanning through your forum, i noticed a possible link to the
maxInactivityDuration and have set it to 0 for the tcp transport on the
broker. This SEEMS to help but it SEEMS not to help in the case when clients
are connecting through a proxy server.

Firstly, can you help me with resolving this issue? Is there further
optimization to be made on the broker/client?

Ok, my second question is more general. When i have a number of clients
connected to a broker which is embedded in a VM with some other service
which the clients communicate with over the broker, it is often necessary to
restart the services. Obviously this will also restart the broker. Should i
expect that the clients will reconnect cleanly including recreating all

Again i have looked through your forums and it SEEMS that this should work
and am sure i have tested this. At the same time though, when i do this in
the case where there are many more clients connected i receive many
exceptions in the broker with the message : Client:
ID:test-45964-1150966470288-1:5 already connected.

Can you please explain the reconnect process? What can i expect and what
should i definitely NOT expect?

Finally, when i set a prefetch policy to 1000 (which is recommended in your
documentation for high throughput on fast connections) i often receive the
error message that the message queue is full with 300 messages and that
other threads may block. 

I am wondering where this message limit size is set and how this could ever
be smaller than a prefetch limit for my connection? Any information that
will give me a better understanding of this topic would also be appreciated.

Many thanks in advance.
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