Thanks, and yes: I'll ensure tests cover rebinding where the values are absent.

Aled


On 20/08/2015 13:20, Alex Heneveld wrote:

aled-

+1 multiple booleans. something might be disabled but not deprecated. there would be no functional difference but it might be a semantic difference.

can we make sure persisted state is happy if the entry is absent, it just defaults to false?

best
alex


On 20/08/2015 13:12, Aled Sage wrote:
Hi all,

I'd like to finish this soon, so would like to reach consensus:

I lean towards boolean for deprecated:

 * because disabling/enabling shouldn't clear whether it is "deprecated"
 * because google images use a separate piece of metadata for each of
   deprecated, obsolete and deleted (and hopefully they thought about
   it a lot; they also have "reason").

---
We can refactor it later - it's (mostly) back-end stuff.

However, we'd need to be careful to transform the catalog item's persisted state (which will store the booleans).

The REST API also implies a mental model of separate metadata properties. The api allows:
    POST /v1/catalog/{itemId}/deprecated/true
    POST /v1/catalog/{itemId}/deprecated/false
    POST /v1/catalog/{itemId}/disabled/true
    POST /v1/catalog/{itemId}/disabled/false

An alternative would be something like:
    POST /v1/catalog/{itemId}/availability/available
    POST /v1/catalog/{itemId}/availability/deprecated
    POST /v1/catalog/{itemId}/availability/disabled

Aled


On 19/08/2015 14:55, Aled Sage wrote:
Thanks Alex, all,

I'd just finished implementing the basic "boolean disabled" functionality [1].

Yes, disabled is stronger than deprecated.

Enumeration: interesting suggestion. Not sure - hard to know what if any other states we'd add, and whether there's any use-case for setting as both deprecated + disabled. I am tempted to change to an enumeration, even though I don't want to have to do more work on it right now!
Thoughts?

"Replacement" field (as GCE have). Nice idea. Can be added separately/later, I think. Normally it's because there is a newer version of the blueprint that should be used instead, which is fairly self evident. But I'm sure it would be useful in other situations.

Aled

[1] https://github.com/apache/incubator-brooklyn/pull/850 (but needs rebased against master for package renames)


On 19/08/2015 14:36, Alex Heneveld wrote:

+1 to the idea of "disabled"

Presumably disabled is stronger than deprecated. Do we want both as booleans or an enum e.g. "availability" ?

Could be nice to have a "replacement" field (which can be set to refer to a catalog item to use instead) and perhaps an availability_comment (free-form text on why something is deprecated/disabled)... just some thoughts.

--A



On 19/08/2015 14:20, Andrea Turli wrote:
Hi Aled,

not different, simply I was wondering if a schema like the one used in GCE

{
"state": string,
"replacement": string,
"deprecated": string,
"obsolete": string,
"deleted": string
}

could have been of any help.
Seems like `disabled` is similar to `obsolete` so your proposal is in line
with GCE approach, I think.

My two cents,
Andrea

On Wed, 19 Aug 2015 at 15:06 Aled Sage <[email protected]> wrote:

Hi Andrea,

We are attaching metadata to the persisted catalog item. One can
explicitly set "deprecated" on a catalog item, and the proposal is to
add support for "disabled".

Is the GCE metadata a different approach from this?

Aled


On 19/08/2015 13:02, Andrea Turli wrote:
Aled,

interesting problem!

I don't want to confuse things, but this reminds me of something I've
seen
before. Could metadata attached to the blueprint be an idea, like they do
for images at GCE [1]?

Best,
Andrea

[1]:
https://cloud.google.com/compute/docs/reference/latest/images/deprecate
On Wed, 19 Aug 2015 at 12:11 Alasdair Hodge <
[email protected]> wrote:

Agree with your proposal, Aled: WARN on deployment of any
deprecated/superseded catalog item, but permit it. Could also emit a (different?) warning when rebinding to deprecated catalog items, but that's less important IMO. I might even suggest that deprecated items
should still be available in the UI, but clearly discouraged for
deployment.

Agree with "disabled" in principle, but wonder how likely is it that
users will actually maintain that attribute on old catalog items.
Probably the best (== least surprising) available option however.

Your customer might appreciate a launch option or brooklyn.property to
force deprecation warnings to be treated as errors, much like
configurable IDE settings for various compiler warnings. "--strict" or
something.

A.
--
Alasdair Hodge
Principal Engineer,
Cloudsoft Corporation


On 18/08/2015 20:01, Aled Sage wrote:
Hi all,

A customer has asked that Brooklyn give an error when attempting to
deploy "deprecated" catalog items (i.e. refuse to deploy them).

In my opinion, this is not quite the classic meaning of "deprecated"
[1,2]. I suggest we add another state for catalog items (e.g.
"disabled").
Do people agree? Or think we should change the behaviour of deprecated?

_*Existing behaviour*_
Items in the catalog can be marked as deprecated. This means the item
is
still kept in the catalog, but its metadata says "deprecated".

In the Brooklyn web-console "add application" wizard, the deprecated item is hidden. However, if you specify that exact version in YAML,
then
you can still use it.

Note: it's important to not delete the catalog item if any applications are using it. On rebind (i.e. restarting Brooklyn), we want to be able to find the catalog item for class-loading purposes (e.g. to find out
the right OSGi bundles).

_*Proposal*_
We leave "deprecated" to have (mostly) the existing behaviour. We
augment this to log.warn whenever an app is deployed that is
deprecated.
(It would be nice to show in the web-console that a deprecated app was
used, but I suggest we defer that).

We add "disabled". When a catalog item is disabled, it cannot be used
for deploying new apps. Any such attempt would give an error.

_*In the future...*_
Longer term, we could consider changing the behaviour of "deleting" a catalog item. For example, the item would no longer be listable or usable. However, it would not be expunged from the catalog until there were no more active uses of that catalog item. This would be detected
automatically (akin to garbage collection).

We could perhaps add an "expunge" for catalog items that entirely
deleted it from the catalog, even if app instances existed.

Aled

[1] https://en.wikipedia.org/wiki/Deprecation
       "indicate that it should be avoided"
"a feature, design, or practice that is permitted but no longer
recommended"

[2] http://docs.oracle.com/javase/7/docs/api/java/lang/Deprecated.html


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