I will add another couple of thoughts on this topic. I totally get that,
and I agree.
My thinking though is that outside testing, where yes, it could be very
convenient, I doubt it will find much use in production. The main reason
is that one would very likely have to change code in order to
reconfigure the broker. In practice, there are way more stringent rules
for code deployment than configuration changes. Sometimes that's what
one wants, treating configuration as code and limit changes, but then
one could very well deliver the activemq.xml configuration in a
jar/bundle with the same effect.
So anyway, from a production perspective, very limited benefit, I see it
mostly as bloat. From a community perspective, I have very bad
experience with larger jars, with a large number of packages and
classes, sometimes just alternatives for each other. They tend to be
confusing and off-putting for new contributors. From a vendor
perspective, I do see the appeal of providing more 'features'. I try to
resist the temptation.
I hope that clarifies the rationale behind my previous statements.
Cheers,
Hadrian
On 03/16/2015 08:39 AM, Dejan Bosanac wrote:
I like this approach of configuring the brokers. I see it as as very
powerful tool for writing complex unit tests, which can make our lives
easier. On the other hand, I don’t see any reason why wouldn’t we include
it in the code base. It doesn’t affect the core, so it’s not a
stability/performance risk, nor it is a big maintenance burden.
Regards
--
Dejan Bosanac
----------------------
Red Hat, Inc.
[email protected]
Twitter: @dejanb
Blog: http://sensatic.net
ActiveMQ in Action: http://www.manning.com/snyder/
On Sat, Mar 14, 2015 at 1:44 PM, Jakub Korab <[email protected]>
wrote:
The end() idiom was just something I put in to make it clear when an
element was closing (there's no way to easily express the difference
between an attribute and a subelement of a config node, or when an element
is finishing). I'm not married to any particular syntax here, and it
definitely has room for improvement.
Just to refer back to my previous reply to Hadrian, imagine this sort of
thing, and you get a much better idea as to where my thinking is heading
with regard to the power of a DSL.
String[] destinationsToReplicate = new String[] {"a", "b", "c", "d",
"e"...};
List<VirtualDestinationDefinition> virtualDestinations = new
ArrayList()<>;
for (String destination : destinationsToReplicate} {
virtualDestinations.add(
compositeQueue(destination) // statically included method
.forwardOnly(true)
.forwardTo()
.queue("toNY." + destination)
.queue("toLN." + destination)
.topic("audit." + destination));
}
ActiveMQBrokers.broker("TY.orderRouter")
.destinationInterceptors()
.virtualDestinationInterception()
.withVirtualDestinations(virtualDestinations)
.networkConnectors()
.networkConnector("TY-NY", "tcp...")
.staticallyIncludedDestinations("toNY.>")
.networkConnector("TY-LN", "tcp...")
.staticallyIncludedDestinations("toLN.>");
Tiny amount of code, lots of work being performed, easy to comprehend and
maintain.
If you had multiple brokers in different geographical locations, you could
inject all the string values from some config into a template broker
definition, and have a standard deployed process that uses this DSL spin up
a uniformly configured broker specific to that location. That's something
you can't do with ease right now.
Jakub
On 13/03/15 22:18, David Jencks wrote:
Unfortunately your sample didn't show up on the mailing list…. I had to
resort to looking at nabble.
I think your example is too simple to see the benefits of a fluent api.
For instance, you haven't added an object that itself needs configuration
to a collection (e.g. transport connector). My experience is that they
make configuring anything reasonably complicated 10x simpler and more
pleasant :-)
That being said….. I'm not familiar with the ".end()" idiom. Is this
common? "standard"? I'd think it would be less confusing if they were
.endTransportConnectors() etc so it was clear what you were ending.
thanks
david jencks
On Mar 13, 2015, at 5:32 PM, artnaseef <[email protected]> wrote:
I see "fluent is easier" as a valid argument to maintaining the project,
but
not necessarily as a reason to pull it into the ActiveMQ main code base.
Still, I am 50/50 on this myself. I personally don't have a need for
simpler configuration of embedded brokers. Also, the syntax of fluent
builders doesn't appeal to me personally, so that makes it harder for me
to
buy-in. For example:
Seems simpler to understand than (I'm making this one up - not using the
posted language):
With that said - I acknowledge this is my opinion and welcome some
discussion of the benefit of including the code inside of ActiveMQ itself
(beyond the well-understood "it will then be maintained with the core
code").
Art
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