On 23 Oct 2009, at 10:16, Fred Moore wrote:
> Hi folks,
>
> I'm an IBM WebSphere MQ veteran new to ActiveMQ, I recently started
> exploring ActiveMQ: great product, really great features... with some
> aspects just a little bit confusing for senior citizens like me :-)
> coming
> from years dwelling in WMQ-land.
Welcome to ActiveMQ land - there's some senior citizens here too.
>
> My general question here is: are there any resources available for
> quickly
> getting experiences WMQers up to speed with ActiveMQ?
>
> Moreover I have a few more specific but very newbie level questions,
> in case
> someone has the patience tackle them:
Yeah right - not fooled by this - bound to be something canny in an
email this long ;)
>
> 1\ In a broker2broker scenario (BRK1 --> BRK2) in the event of a
> network
> outage msgs will pile up on the BRK1
> 1.1\ where will they be internally stored? a hidden queue or
> something like
> it? (in WMQ a "special" queue called trasmission queue handles this).
> 1.2\ how can I inspect how many messages are waiting to be delivered
> to a
> particular remote broker?
Well, unlike WMQ AMQ doesn't make special provisions internally for
networks - they just appear as another consumer (there are a few
nuisances - but nothing to worry about - yet).
>
> 2\ In a broker2broker scenario (BRK1 --> BRK2) I want to send a
> message from
> BRK1 to a queue Q2 residing on the remote broker BRK2, the appropriate
> network and protocol connectors are already in place
> 2.1\ Do I have to define any queue/pointers on BRK1 to point to
> Q2@BRK2? (in
> WMQ a "special" queue called remote queue definition handles this)
In AMQ all Queues are "global" - in that they will be shared across
networks - there is some flexibility around this - see included/
excluded destinations on the Network Properties here: http://activemq.apache.org/networks-of-brokers.html
> 2.2\ ...if not: does this mean that conceptually all queues in a
> network of
> connected brokers belong to the same "namespace" (i.e. Q2 is known
> to be
> residing on BRK1 by all brokers in the network)
Yes - they are all global.
> 2.3\ ...if so: what happens to message routing when two queues with
> the same
> name are defined on two distinct interconnected brokers? (in WMQ
> Clusters
> (good feature, bad name: it's not related to HA) this causes dynamic
> workload distribution between the two queue instances)
Same thing happens in AMQ - though network subscribers can have their
priority lowered - see the decreaseNetworkConsumerPriority - so
messages at the local broker will be routed to local subscribers first.
>
> 3\ In a broker2broker hub & spoke scenario (BRKH being the hub,
> BRKS1 BRKS2
> BRKS3 being the spokes) I want enroll a new spoke broker BRK4
> without having
> to touch BRKH configuration
> 3.1\ Is it correct to say that all I have to do is plug a network
> connector
> to BRK4 pointing to BRKH?
Yes - you can do that - but you have to ensure that the duplex
property is enabled. By default networks are one way - they push
messages (if there are interested subscribers) to the remote broker.
> 3.2\ Is it correct to say that setting the network connector attribute
> duplex=true will enable full two way connectivity between BRK4 and
> BRKH?
Yes.
>
> I guess this is more than enough for a first post!
>
> Thanks in advance and congrats for the product, I hope to have the
> chance of
> seriously working with it soon.
> Cheers,
> F.
>
> PS: ...hey any Hursley lurkers out there? :-)
No Hursley lurkers - there are one or two of us in the UK - but we
have been rightly kept out of the posh end :)
cheers,
Rob
Rob Davies
http://twitter.com/rajdavies
I work here: http://fusesource.com
My Blog: http://rajdavies.blogspot.com/
I'm writing this: http://www.manning.com/snyder/
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