Hi Mark,
See comments in-line -
On 11/16/2011 03:23 AM, Mark Thomas wrote:
> On 12/11/2011 02:33, Rajiv Mordani wrote:
>> As part of Java EE 7 one of the areas of focus is - multi-tenancy / PaaS
>> style deployments of applications. As I have sent previously to the EG
>> the current proposal for Java EE Platform as for PaaS as it stands today
>> is described at [1].
>>
>> I would like to start the discussion around the requirements for what it
>> means for the Web Container. In particular for the multi-tenancy aspect
>> in a PaaS environment, what are the customizations that each tenant can
>> provide and how they will be reflected in the spec. Some initial
>> thoughts that I had are listed below -
> I think there is a more fundamental question to address before we get to
> the level of detail below. My reading of [1] is that the workflow is:
> a) an application is uploaded
> b) one or more instances of an application is configured for a specific
> tenant
> c) the instance(s) are started
Yes that is right.
>
> The question for me is where does the WAR feature in this? I see two
> possible approaches:
>
> 1. The WAR is uploaded in a) with place-holders for tenant specific
> information. The WAR from a) and the tenant specific information from b)
> is passed to the container that creates a tenant specific instance for c)
What you list above is the approach that is the current thinking and not
what you have
listed below. The war that is uploaded in a) may not have to be
customized at all for a
tenant and a tenant may just use all the "defaults" provided in the war
file as is. What
we need to look at is if a user wants to customize the war file uploaded
in a) how do
we go about doing that. It is almost like being able to provide a
"web-fragment" which
overrides the contents in the war file. However in Servlet 3.0 we did
it the other way
where the web-fragment was in the war and was overridden by contents in
the app.
Even resources being served out of a jar file was required to be in the
war file.
- Rajiv
>
> 2. An application template is uploaded in a) which is then combined with
> tenant specific information from b) to create the WAR which is deployed
> in c).
>
> I think approach 2 is a lot simpler to work with as it means minimal
> (no?) changes to the current specification as all the tenant specific
> work happens during the deployment process before the WAR is deployed.
> My discussions with various folks at JavaOne led me to understand this
> was the intended approach and that multi-tenant WAR files were not the
> intention.
>
>> * URL mapping
>> * init-params
>> * Customization of resources to be loaded per tenant - style sheets,
>> jsps, error pages etc
>> * Customized DataSources and other resource-refs per tenant
>> * session related configuration (timeout, tracking mode, isHttpOnly,
>> security setting etc)
>> * security roles constraints per tenant (should we allow every tenant
>> to change this for the application)
> Pretty much everything in web.xml needs to be parameterized. I have some
> thoughts on the above but I'd like to address the more fundamental
> question before delving into the detail.
>
>> * keystores, certs for an application (can we even do this per tenant)
> I don't think this is possible. Until the JRE supports SNI on the server
> side I see no way to do this. Even that will require one host name per
> tenant (not a bad thing).
>
> Mark
>
>> What else am I missing here?
>>
>> [1] http://java.net/downloads/javaee-spec/PaaS.pdf
>>
>> - Rajiv