On 23 Apr 2008, at 00:27, deepak.kumar wrote:
Hi Folks,
I'm hoping this is an easy one to answer for some of you.
Been using AMQ 4.1.1 for a couple of months now, and only just
noticed
that messages on topics with durable subscriptions were not being
persisted
across restarts, which seems like a bit of problem :confused:. At a
high
level, here are the steps I follow:
- Disable all consumers
- Put a few messages on topic
- Verify topic size is non zero using JMX
- Restart AMQ
- Notice topic size is zero again.
The message producer definitely sets the
javax.jms.DeliveryMode#PERSISTENT flag (we use Spring's
JmsTemplate), and
the broker is configured as follows :
<broker useJmx="true" xmlns="http://activemq.org/config/1.0";
brokerName="localhost"
dataDirectory="${activemq.home}/activemq-data/"
[[SNIP]]
<persistenceAdapter>
<journaledJDBC journalLogFiles="5"
dataDirectory="${activemq.home}/activemq-data/journaledJDBC"/>
</persistenceAdapter>
[[SNIP]]
</broker>
I've also tried several combinations of the following :
- AMQ Versions 4.1.1, 4.1.2 & 5.0.0
- PersistenceAdapter kaha & journaledJDBC for the 4.1.x and
amqPersistenceAdapter for 5.0.0
- Within the journaledJDBC, 2 different data sources, mysql & derby
embedded.
- Set persistent="true" on the <broker>
What am I missing? I've spent the better part of today scouring the
internet
for leads, and reading through documentation with little success. If
someone
could right this ship, I'd really appreciate it.
I guess more specifically, the questions I've been unable to answer:
- Is AMQ capable of preserving messages across restarts?
- Is AMQ capable of preserving messages across restarts using an
embedded
derby instance?
- And the golden ticket : does anybody have configuration they can
share to
make it so ? :-D
Regards,
Deepak.
--
View this message in context:
http://www.nabble.com/Persisting-messages-across-restarts-%28AMQ-4.1.1---4.1.2%29-tp16827035s2354p16827035.html
Sent from the ActiveMQ - User mailing list archive at Nabble.com.
Hi Deepak,
you might have run into a common gotcha with durable topic
subscriptions - there is a faq - http://activemq.apache.org/why-do-i-not-receive-messages-on-my-durable-topic-subscription.html
which actually needs fleshing out a bit - but I wonder if you are
creating your durable topic subscriptions before you send you messages ?
Persistentence works differently between queues and topics - with
queues messages are always persisted - but with topics - messages are
only persisted across broker re-starts if there exits a durable
subscription (it does have to be running - just to have registered an
interest - i.e. started - then stopped).
This is one reason why virtual topics are handy - see
http://activemq.apache.org/virtual-destinations.html
or you could use JMX to create a a durable subscriber - its an
operation on the BrokerViewMBean
cheers,
Rob
http://open.iona.com/ -Enterprise Open Integration
http://rajdavies.blogspot.com/
