Mailing-List: contact dev-help@geronimo.apache.org; run by ezmlm
Precedence: bulk
Reply-To: dev@geronimo.apache.org
Received-SPF: pass (nike.apache.org: local policy)
Message-ID: <4E930085.6000104@cait.org>
Date: Mon, 10 Oct 2011 09:26:13 -0500
From: Russell E Glaue <rglaue@cait.org>
User-Agent: Mozilla/5.0 (X11; Linux i686;
 rv:6.0) Gecko/20110812 Thunderbird/6.0
MIME-Version: 1.0
To: dev@geronimo.apache.org
Subject: Re: Use version suffix for deployment plan file names
References: 
 <CALS1ypDcdp3Kqx31gbXmZnUZwo4uNDX=6+0g9Rzacxv+ynVm=g@mail.gmail.com>
 <4E8A0A2F.2020404@cait.org>
 <CALS1ypBMp3GzewKLa1y4q6m0M3JY=nF=+-vcTh1n+nozvhYXEA@mail.gmail.com>
 <4E8DD71B.5040803@cait.org>
 <CALS1ypDd-XNGgj64MG1jKxFREUgyfpfOhbmPbB=zUTvqzNaOdQ@mail.gmail.com>
 <4E8F5166.30905@cait.org>
 <CALS1ypAaZaHnf=TctiDQZXxybOK=ndJDGocqo7OWPf3ZW9LDyA@mail.gmail.com>
In-Reply-To: 
 <CALS1ypAaZaHnf=TctiDQZXxybOK=ndJDGocqo7OWPf3ZW9LDyA@mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit

So it sounds like, that if we are to do this, we have to maintain the additional
deployment plan at the maintenance release (e.g. 3.1.21 =>
geronimo-web_3.1.21.xml) and cannot maintain it at the minor release (e.g.
3.1.21 => geronimo-web_3.1.xml) for the following reasons:
 1. We might change the schema (add elements) in a maintenance release.
 2. App Developers may need to test between two widely-gapped maintenance
releases (e.g. 3.0.0 and 3.0.55)

And we will only read in one deployment plan, and will not allow configuration
overlap from multiple deployment plan files. (App Developers will have to
practice copying to the version suffix deployment plan, and merge changes from
the default deployment plan.) We will look for the first validly named
deployment plan, but only at the maintenance release level. Such that if the
current release is 3.2.4, we will look for a deployment plan in the following
order (the first one found will be chosen):
1. geronimo-web_3.2.4.xml
2. geronimo-web_3.2.3.xml
3. geronimo-web_3.2.2.xml
4. geronimo-web_3.2.1.xml
5. geronimo-web_3.2.0.xml
6. geronimo-web.xml
7. Else: Fail -> "No Deployment Plan"

During an apps deployment, Geronimo should definitely print out what deployment
plan it is using. E.g.: "Using deployment plan geronimo-web_3.2.4.xml." - or
perhaps this is a message that prints out on higher verbosity, or only in the
server log.


If we have a greater acceptance from the developers, I don't see any reason not
to put this feature in. I will help you write the documentation.

Do we want to backport this to Geronimo 2.X?

-RG


On 10/08/2011 01:25 AM, Ivan wrote:
> 
> 
> 2011/10/8 Russell E Glaue <rglaue@cait.org <mailto:rglaue@cait.org>>
> 
> 
> 
>     On 10/06/2011 10:31 PM, Ivan wrote:
>     >
>     > 2011/10/7 Russell E Glaue <rglaue@cait.org <mailto:rglaue@cait.org>
>     <mailto:rglaue@cait.org <mailto:rglaue@cait.org>>>
>     >
>     >     To make this clear, and allow me to ask a question, let's look at an
>     example
>     >     case study, and tell me if this is how it will happen.
>     >
>     >     A Geronimo User is running G2.2 and want to deploy a G3.0 server
>     side-by-side.
>     >     User has a web application with the deployment plan
>     "WEB-INF/geronimo-web.xml"
>     >     To be able to deploy to both servers, you are suggesting the User
>     needs a second
>     >     deployment plan "WEB-INF/geronimo-web_3.0.0.xml".
>     >     After which, during the User's testing of G3.0.0, G3.0.1 is released
>     and the
>     >     User upgrades to G3.0.1.
>     >
>     >
>     >     I did not mean that the users have to provide an extra file for 3.0.0
>     > server. It is only required when some incompatible features are used. e.g.
>     > import-package. For the server deployer, it will first check whether there
>     is a
>     > specific plan file for the current version, say geronimo-web_3.0.1.xml, if it
>     > exists, use that file, or it will check the geronimo-web.xml file.
> 
>     Yes, I understand that it is optional. Sorry I was not clear. I was meaning if
>     the developer wants to use the optional geronimo-web_3.0.0.xml file, do they
>     have to rename it to geronimo-web_3.0.1.xml when they upgrade G3 from 3.0.0 to
>     3.0.1? And you answered that below, in the next block, which is we could read
>     them all in.
> 
>     Which one has precedence? geronimo-web.xml or geronimo-web_3.0.1.xml
>     So I mean, if some feature is declared in both, but configured differently among
>     both, which one is the final accepted configuration? I would assume that the
>     version-suffix deployment plan holds the final configuration - is this your
>     suggestion?
>      
> 
> 
>     >
>     >     Are you saying the User needs to either rename
>     "WEB-INF/geronimo-web_3.0.0.xml"
>     >     to "WEB-INF/geronimo-web_3.0.1.xml", or create a new deployment plan as
>     >     "WEB-INF/geronimo-web_3.0.1.xml"?
>     >
>     >
>     >     That sounds fine to me for small case scenarios like this.
>     >
>     >
>     >     For the minor version, maybe we could make the algorithm more elegant, the
>     > deployer will also check the file for 3.0.0 exists if current version is
>     3.0.1 ?
> 
>     We could search for all files matching the name /geronimo-web.*\.xml/, sort
>     them, and read the content in accordingly, overlaying the structure on top of
>     each other as we ascend from geronimo-web.xml to geronimo-web_X.X.X.xml.
> 
> 
>     Firstly, if there are multiple files in the directory, it looks to me that
> only one will be used, as merging multiple files may introduce some odd issues.
>     For the precedence order, my rough idea is :
>     a. strict version matches
>     b. backward searching all the files belong to the same major and minor
> version. If the running server is 3.0.21, the deployer could search 3.0.20 -> 3.0.0
>     c. default file, e.g. geronimo-web.xml
> 
> 
> 
>     >
>     >
>     >     Can I ask just for the sake of asking, assuming we are not removing schema
>     >     elements of the deployment plan between maintenance revisions, is it
>     sufficient
>     >     to recognize the deployment plan by minor revision instead of by
>     maintenance
>     >     revision?
>     >
>     >
>     >     We usually do NOT remove the unused elements in the schema files, and with
>     > this, it is possible to keep forward-compatibility, which means those old
>     > deployment plan files could still be used without no change in the new server,
>     > and deployer will print some warning message to notify the users those unused
>     > elements are deprecated. The problem here is that, how to make the
>     > back-compatibility, and how to make the deployment plan with new added
>     elements
>     > could be used in a previous server.
> 
>     If a user wants to deploy in both Geronimo versions, this will certainly require
>     them to be pragmatic about it. But I think it is a good idea. A developer can
>     maintain a web application for an older version, while at the same time testing
>     it with a newer version using the suffix-versioned deployment plan. I know, in
>     real life, our developers with my employer would benefit every time I upgrade
>     versions and the schema changes. We have ran into hiccups in this migration
>     process, which your suggestion would help alleviate.
> 
>     But my previous question:
>     Do we add schema for new features in maintenance releases?
>      Say between G3.0.0 and G3.0.21?
>     Or do we restrict adding schema for new features to minor releases?
>      Say between G3.0.0 and G3.1.0?
> 
> 
>     I think that it depends on, and so far I did not see there is a related rule
> in the community. Please figure it out if I missed it :-)
>     Mostly, schema files will not change usually, and we even do not update the
> schema versions if we only add the new elements (this is actually what we always
> do), which will not break the compatibility, those old files could be validated
> successfully with the new schema.
>     The recent big changes in the schema is incoming Geronimo 3.0 beta. due to
> the OSGi integration, and it only add new elements.
>  
> 
> 
>     I ask because I was considering it would be less confusing and more easily
>     manageable if the version-suffix deployment plans we maintained at the minor
>     version, rather than the maintenance version - this is as long as we are
>     restricting schema changes to minor releases - we probably would not want to do
>     this as I suggest if we allow schema changes in maintenance releases.
> 
> 
>     Yes, any new feature should not bring confusion to the users, or it is not a
> good feature :-) In my expectation, the users only need to add a new
> version-suffix deployment plan files id they have to take advantage of those new
> features, and usually, they just need to leave the files there. e.g. If the
> application has to support both geronimo-2.1/2.2/3.0, and a new file is required
> for 3.0, he could just create a default file geronimo-web.xml for 2.1 and 2.2,
> and one new file geronimo-web-3.0.0.xml for 3.0. In the future, if a new feature
> is imported in 3.0.12, they could just create a file named geronimo-web-3.0.12
> there.
>     
> 
>     >
>     >
>     >
>     >     So instead of "WEB-INF/geronimo-web_3.0.0.xml" and
>     >     "WEB-INF/geronimo-web_3.0.1.xml", the deployment plan file
>     >     "WEB-INF/geronimo-web_3.0.xml" would suffice and cover both cases.
>     >
>     >     -RG
>     >
>     >
>     >     On 10/05/2011 07:59 PM, Ivan wrote:
>     >     > I think that the number should be consistent with the running Geronimo
>     >     version,
>     >     > and it looks to me this change is kept in the all future versions
>     >     >
>     >     > 2011/10/4 Russell E Glaue <rglaue@cait.org <mailto:rglaue@cait.org>
>     <mailto:rglaue@cait.org <mailto:rglaue@cait.org>>
>     >     <mailto:rglaue@cait.org <mailto:rglaue@cait.org>
>     <mailto:rglaue@cait.org <mailto:rglaue@cait.org>>>>
>     >     >
>     >     >     This would be a good option to support cross version compatibility.
>     >     >
>     >     >     Would the suffix remain the same for minor releases, or would we
>     >     increment the
>     >     >     version number in the suffix (i.e. geronimo-web_3.0.1.xml)?
>     >     >
>     >     >     In what future version would this feature be deprecated? Or would we
>     >     support
>     >     >     this methodology in all future versions?
>     >     >
>     >     >     -RG
>     >     >
>     >     >
>     >     >     On 10/01/2011 02:43 AM, Ivan wrote:
>     >     >     > Hi, although we are trying to make the deployment plan
>     compatible among
>     >     >     > different versions,there are still differences. e.g. some OSGi
>     >     metadata are
>     >     >     > imported in the latest 3.0 release. So, if the users would hope to
>     >     use the
>     >     >     same
>     >     >     > application package for different versions, there may be an
>     issue. I am
>     >     >     thinking
>     >     >     > that we could use version as suffix for the deployment plans. For
>     >     the web
>     >     >     > application, Geronimo will first try to find a
>     >     geronimo-web_3.0.0.xml in the
>     >     >     > WEB-INF directory, if not it will uses geronimo-web.xml file.
>     With this,
>     >     >     it may
>     >     >     > get the life easier.
>     >     >     > Thoughts ?
>     >     >     >
>     >     >     > --
>     >     >     > Ivan
>     >     >
>     >     >
>     >     >
>     >     >
>     >     > --
>     >     > Ivan
>     >
>     >
>     >
>     >
>     > --
>     > Ivan
> 
> 
>     -RG
> 
> 
> 
> 
> -- 
> Ivan