Dain,
David is talking about how SessionManagers (effectively extended
SessionFactories) should be plumbed into Geronimo (i.e. GBeans), not
about the API's describing Sessions themselves.
I've looked at the stuff in modules/session - it looks very similar to
some WADI internals - there is loads of overlap here. I have some
serious plans for converging WADI with ActiveSpace and would be happy to
consider further changes to reuse or contribute to your sessions module.
We should talk.
I'll jot my ideas down and post them shortly.
cheers,
Jules
Dain Sundstrom wrote:
Are you proposing a new API? I think the session management API
James and I wrote will satisfy these needs. I suggest you take a
look at:
modules/session/src/java/org/apache/geronimo/session/Locator.java
modules/session/src/java/org/apache/geronimo/session/
SessionLocation.java
modules/session/src/java/org/apache/geronimo/session/Session.java
I believe that these APIs capture all the needs of a component that
requires client session data storage.
-dain
On Jan 26, 2006, at 4:36 PM, David Jencks wrote:
I have some ideas about how to set up web clustering in terms of
geronimo modules and configurations and connections between gbeans.
I've talked with Jules and Jeff about this and think that they agree
that this is a good starting point so I'll try to describe it and
possibly even help implement parts of it.
There are quite a few questions I'm going to ignore, such as EJB
SFSB clustering and the new session module James and Dain wrote and
how it might relate to the web clustering stuff. We have to start
somewhere.
For me, one of the most important factors is that the clustering
solution be pluggable, in particular that you be able to run
geronimo without any clustering classes. This means that each
clustering solution needs to be packaged in one or more
Configurations or modules and that communication to the clustering
module be done through interfaces defined in a more core geronimo
module. It also implies that the all the web containers should
communicate with the clustering implementation through the same
interface(s).
I'm proposing that the interfaces be SessionManagerFactory and
SessionManager, the factory being able to provide SessionManager
instances. I see the SessionManagerFactory being deployed as a
GBean and made available to web containers through a gbean reference.
My understanding is that for both jetty and tomcat, the web app
context needs an instance of a session manager. Therefore I propose
giving each web app context a reference to the session manager
factory gbean. At an appropriate lifecycle point it can get the
session manager it needs. In Tomcat IIUC a host or engine can also
be where a session manager is configured. We don't really need to
support that directly since we can in our deployer push a reference
to whatever "global" session manager may be configured down into
each web app context.
I see the jetty and tomcat builders installing references to
appropriate session manager factory gbeans. IIUC there is a lot of
configuration possible for at least WADI, and we should be able to
support running multiple session manager configurations at once, as
follows:
- there can be a default session manager (say WADI) configuration,
and the name of its session manager factory gbean can be configured
in the web app builder(s). This will be used for distributable web
apps that don't specify in their plan a different session manager
factory gbean.
- a web app plan can contain an explicit reference to a specific
session manager factory or an entire session manager factory/WADI
configuration.
- we can use a namespace driven xml-reference builder to construct a
wadi configuration inside a SMF reference (maybe :-)
There are a couple loose ends I can see and probably lots more I can't:
-- I imagine we want to be able to have pluggable session managers
for non distributable apps or in the absence of clustering. I don't
know if we'd want 2 "default" session manager factory gbeans
available, one for cluster and one not, or if there is a better
solution. Having 2 and having the builder decide which you get seems
simplest at the moment.
-- We need to be able to support the non-wadi existing tomcat-
specific clustering, and it is unlikely this can be coerced
effectively into the proposed geronimo SMF and SM interfaces. We
could support this with another gbean and interface, but at the
moment I'm leaning towards giving the web app context either a
separate gbean reference to the tomcat specific clustering or
directly installing the tomcat solution into the web app context.
Comments? Flames?
thanks
david jencks
--
"Open Source is a self-assembling organism. You dangle a piece of
string into a super-saturated solution and a whole operating-system
crystallises out around it."
/**********************************
* Jules Gosnell
* Partner
* Core Developers Network (Europe)
*
* www.coredevelopers.net
*
* Open Source Training & Support.
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