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
q...@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/
