Re: facelets & jdbc (homework)

Thufir wrote:


Yes. You would have to provide more libs yourself, like dbcp. You lose some
capabilities like container-managed actions, which are a large part of the
appeal of an app server. It is a way to reach out to secondary data sources
or to gain extremely fine-grained control of the connections.

I go the other way for libs generally, pushing standard ones into the Tomcat
environment, say the JSF JARs.

For databases specifically, it really makes no sense to package the libs with
the WAR. How many different JDBC flavors do you need for all the apps running
on any one server? Postgres, Oracle, SQL Server, DB2, MySQL, Derby. Six.

OK, twelve. I'll even make room for that other 0.1%.

That's not a whole lot of freight to put on the app server, and makes a
deployer's life much easier.

As programmers we tend not to concern ourselves much with whether the code
actually runs well, or at all in some cases. We're not contemplating a
context of many apps running under one environment. As deployers we focus on
the often divergent goals of making the apps run well, and making them run
well as a group. Especially for common resources like database access, you
want holistic deployment policies.

You might think this harms portability, but it's quite the opposite. In my
experience it's much harder to integrate disparate resource access policies
than to have applications count on the app server for universal resources.

Furthermore, Tomcat has a lightweight deployment footprint, in both human and
infrastructure resources. It's constructed to permit virtual hosting and
multiple server instances that share common resources. It's pretty much as
cheap to provide separate resources per Tomcat instance as per application
instance.

My quixotic quest is for the balance between deployment power and complexity.
  Programming is only half the story. Maybe less. Too many XML files make me
feel shattered and overwhelmed, and take forever to coordinate. Too much
hardcoded, or tightly coupled to the individual application, makes operation
sluggish and has its own penalties on deployment.

Mind you, I speak from the small-team or solo standpoint. Things are
different if you have the scale where people specialize in operations. Or are
they?

--
Lew