activemq-users mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Kuppe <>
Subject Re: LastImage-style topic
Date Wed, 31 May 2006 13:26:28 GMT

Thanks James for the quick reply.

I understand that they are two different topics. I was only trying to
demonstrate the scenario that is interesting to me. Everytime that the
client receives messages it is only receiving the most recent and none of
the previously updated messages - somehow receive latest image.

So after reading the MessageEvictionStrategy, it seems that i need to
implement this interface and therefore implement the
evictMessage(LinkedList) method. My implementation would receive a linked
list of messages which are ordered by time, and i should return a
MessageReference referencing a message that can be evicted. Is this correct?

I assume then that this should be accompanied by a
PendingMessageLimitStrategy which will force the MessageEvictionStrategy to
be used. Is this correct?

I also assume then that i could implement my own PendingMessageLimitStrategy
that would determine just how many messages are valid for all messages in
the queue. But the javadoc describes that the number returned from the
getMaximumPendingMessageLimit is based on the messages currently in the
message queue and is in excess of the prefetch size for the subscription.

Are both of these interfaces pluggable in the configuration? If so, how do i
plug in my own specific implementation. It seems the examples given show
only an alias for the implementation class.

Still, it seems that it is not possible to configure a way of constantly
overwriting the latest price with a new price in the message queue. So if i
have 5 updates for a specific symbol from the publisher between two receives
from the consumer, it may still need to receive stale updates to get to the
latest  quote. Ideally an update could expire the previous...

Still, perhaps i am trying to push a square peg through a round hole. I hope
you can offer some insight...

Thanks in advance.
View this message in context:
Sent from the ActiveMQ - User forum at

View raw message