Some good points emerging from this discussion! :-)
Would it be a nice idea to put following on wiki:
1) State goals/philosophy for C2 in light of lessons learnt from 1.x
development - lean, mean, extensible (~add any other here~)
2) Document *all* features/requirements we want to see in C2 on wiki
(even if they are already present in 1.x!).
3) Draw a proposed architecture.
4) Assign items in (1) a priority/weight. Add use-cases to each item in
(1) to determine this.
5) Group the priortised requirements/features into milestones.
6) Start cutting code.
PS: Codehaus wiki seems to be very slow. Any chance we can have a space
created on Apache wiki? Or, I guess it will have to wait for TLP vote.
Brett Porter wrote:
This looks very exciting, and agree with most of the thread that
follows. I'm just going to reply in summary - most of my thoughts are
actually non-technical :)
Regarding databases: I don't think xml files are the solution (except
for the configuration where it makes a lot more sense :) - the data
needs to be queryable. I think Andy made a good point in his comment
on the roadmap - we need to look at the actual problems. Here's what I
think needs to be improved:
- better centralisation of access. The architecture of Continuum
bleeds JDO decisions all through the code since you access lazy stuff
for the first time in obscure places.
- I think this might be that the model is too complicated (sorry, my
fault) - it assumes complex relationships are handled easily. It seems
to be going ok these days, but I feel it would be hard to modify.
I haven't looked at Rahul's branch yet, but I think we should consider
a more decoupled database (ie, lookup build results for a project but
keep them separate in the model to avoid the need to lazyload 90% of
the time), and more centralised database logic. I would consider JPA
just because it gives more options in terms of an implementation. It
is quite easy to use from a development standpoint. But we also need
to consider what functionality is needed up front - I think high on
the list needs to be migrations between versions. Also, We are
probably going to need to store more data in the future, and be able
to query it (particularly historical datapoints).
On the container: I would prefer to move off Plexus simply because
it's a moving target and it's a barrier to entry for new developers.
Now, my more general observations. Firstly, the roadmap doesn't appear
to have any features - these are all technology changes. Some of that
might be cool and a feature in itself, but I think there needs to be a
balance between evolution, features, and bugfixing. I would also
emphasise that features should be creative new things Continuum can do
(for which we've had plenty of ideas), not just catching up to other
CI servers :)
I think the first part of the roadmap is key - separating the layers
out, and basically building Continuum to be lightweight and
distributed from the ground up. I hope that's the focus of the
development. Note this also impacts the database as it should store
much less information on builder machines (it can ship history back to
the main server).
I also think that supporting plugins is a good idea - it has been a
huge bonus in other apps and in Maven itself. I'd like to investigate
using OSGi for this.
But by far the biggest question I have is what happened to 1.2? I
think Continuum needs to set a target to achieve, but get there in
gradual steps that at each stage sees a production release. The long
1.1 cycle really set Continuum back - a lot of it was changing
features, but there was also a lot of changing technologies :) I don't
think Continuum will survive another year-and-a-half release cycle. So
the start could be to break all the actions out (plexus, not webwork)
into services and add some features, then the next release could
adjust the database model and add some other features. And as we split
these things out we make sure they are nicely documented and tested.
That's my thoughts :)
On 30/01/2008, at 9:34 AM, Emmanuel Venisse wrote:
I started a document  with my ideas about Continuum 2.
As you can see in this doc, I want to add lot of things in the next
Feel free to comment on it.