I'll try answering some
Tom Amiro wrote:
> Hi,
>
> I'd like to share questions we were asked by attendees at our
> Glassfish pod during Boston Tech Days. For some, I'd like to get back
> to the person with a good answer; for others, it just would be good to
> know more.
>
> * Is there a way to secure communication between client and
> service without having to manually install certificates on
> systems? Maybe an API to create certificates or a way to
> dynamically establish trust?
> * Is there a simple way to change the admin user's password using
> the Admin Console?
> * In reference to the Clusterjsp demo we showed, one attendee
> asked what are instances and is there any legitimate use for
> having a cluster on a single machine?
>
Instances are Java EE server processes to which Java EE applications can
be deployed and served from. In a clustered environment, a number of
instances are created to help distribute the load of incoming requests
(assuming these are fronted by a load balancer or an IP sprayer) and to
build redundancy for continued availability of service without
interruption due failure/crash of one or more instances in the cluster.
In other words, a cluster of instances prevents a single point of
failure in the software layer of your topology.
Going a step further, session state replication provides continued
availability of both service and session data so that site's customers
can be agnostic to failures of software processes/hardware.
Having a cluster on a single machine limits the ability to horizontally
scale and creates a single point of failure (that of the machine's
failure). So for a non-mission critical business, one may choose to have
a (hopefully) multi (core or) cpu, single machine with sufficient RAM to
host a cluster of instances to save space, cost and possibly energy
costs. Ideally two boxes at the minimum with 2 network interfaces each
would help bring hardware redundancy for any software service that is
being offered in a cluster of instances.
> * A few persons wanted to see lists of who (companies) are using
> GF. We showed them the blogs.sun.com/stores page, but is there a
> more comprehensive list?
>
correction on the link :
http://blogs.sun.com/stories
>
> * Others asked for statistics on the market share of GF compared
> to other Application Servers.
> * Of course we got the question from quite a few: What is an
> application server?
>
A piece of software that serves applications through the internet to
provide a service.
Java EE Application Servers do this by implementing the Java EE
Specification.
> * Why is glassfish named glassfish?
>
Its see-through :)
>
> * Does the portal server run on GF?
> * Does java.net run on GF?
>
> * One very interested person asked, do you have a sales kit,
> promotional material, brochure, fliers, datasheet, etc that I
> can take to my management to get them interested in GF?
> * Does GF support Ajax?
>
Checkout
http://ajax.dev.java.net or
http://jmaki.dev.java.net and
http://blueprints.dev.java.net for real world ways to use /Web 2.0
/technologies with Java EE.
>
> * Does GF have something comparable to IBM's JAM plugin to support
> mainframe updates?
> * For load balancing, does GF have a plugin for Apache web server?
>
Sun Java System Application Server 9.1 officially supports load
balancing using Apache Web Server and mod_jk plugin, also Microsoft IIS
6 and Sun's Web Server 6.1sp5 and 7.0
A number of blog entries have been written in blogs.sun.com or java.net
on supporting Apache web server for load balancing and proxying to GF.
One such example with additional links in it:
http://blogs.sun.com/dadelhardt/entry/loadbalancing_with_mod_jk_and_glassfish
--Shreedhar
>
> Tom