On 6/19/07, jcm231 <[EMAIL PROTECTED]> wrote:
James.Strachan wrote: > > On 6/18/07, jcm231 <[EMAIL PROTECTED]> wrote: >> >> Hi! >> >> I am have a standalone ActiveMQ server and I am sending messages using a >> producer. The messages include the JMSXGroupID header with two different >> values: "one" and "two". I launch two Consumer objects, both being >> threads >> and implementing the interface MesageListener. The result is that only >> one >> of the two consumers receives all the messages. Sometimes is the first >> consumer and sometimes is the second who receives them all. >> >> What am I doing wrong? It is the first time I use ActiveMQ and I would >> thank >> any help anybody could give me. > > We don't yet guarrentee an exact round-robin dispatch policy on a per > message group basis; consumers tend to eagerly grab as many messages > as will fit into their pre-fetch buffer. > http://activemq.apache.org/what-is-the-prefetch-limit-for.html > > to mimick round-robin, try setting the prefetch to 1 on both > consumers; or try using thousands of messages > > > > > -- > James > ------- > http://macstrac.blogspot.com/ > > I have sent 34000 messages but they all get consumed by the same consumer. I tried to specify the prefetchSize as indicated in: http://activemq.apache.org/what-is-the-prefetch-limit-for.html but I am not creating the ActiveMQQueue on the consumer's code but on the xml file. So I put this on my activemq.xml file: <!-- Destination --> <bean id="destination" class="org.apache.activemq.command.ActiveMQQueue"> <constructor-arg> <value>example.MyQueue?consumer.prefetchSize=1;consumer.exclusive=false</value> </constructor-arg> </bean> but it seems not be effective.
Creating a queue does nothing, unless you actually use it in your JMS client (e.g. to consume from) If you're struggling to set the prefetch groups; try sending say 50,000 messages to group 1, then start mixing 1 and 2; then the first consumer will get its pre-fetch buffer filled with the first group; so it won't grab group 2. (Or have lots of groups) -- James ------- http://macstrac.blogspot.com/
