Since this will be a monthly column on the subject of transactions, which
from my experience seems to be a subject that everybody has heard of, but
nobody is familiar with, I thought I would build up speed with a
back-to-basics look at transactions, what they are and what they're for.
Having worked in software infrastructure for some years, I've found that a
recurring objection to programming to any kind of framework - J2EE being just
the latest one - is that it "adds complexity to development." While I think
that this is demonstrably not true, one of the facets of this style of
programming that I have heard cited as "making things more complex" is
transactions, and the whole business of declaring or coding them (declaring,
hopefully, but more of that in a future column). After all, everyone has
written that killer two-tier app with a pretty front-end and a bit of dr... (more)
I've seen several posts in the public WebLogic server transactions newsgroup
in which people have had problems with transactions spread across multiple
servers.
The gist of these problems is always that they have two EJB components in two
different servers. Bean One on Server One executes in the context of a JTA
transaction in which it calls Bean Two on Server Two, thus propagating the
transaction across to the second server. Finally, the first method ends, and
the transaction commits.
When the time to commit comes, the transaction is aborted. Accompanying the
abort is a crypti... (more)
No, don't worry, it's not a a floor-wax/dessert-topping/toothpaste article
this month; it's simply a look at how multilanguage application environments
might be used together in highly distributed systems. Interested? Well, don't
worry, somebody has to beS Swallow your pride and read on, MacDuff!
Looking at the IT systems of most large organizations is often closely akin
to going on a fossil hunt. You dig through the J2EE surface to find a strata
of C++ code in the supporting layers. Dig a little deeper and you start
finding relics of a bygone age when C and Unix ruled the world. ... (more)
Another discussion based on a weblogic.developer.interest.transaction posting
this month. It's a newsgroup that always proves to be a good source of
information for the world at large when it comes to transactional behavior
(and a good source of inspiration for me when the article time of the month
rolls around again).
This particular posting is a great illustration of how an apparently simple
assumption can pitch you into the bowels of the infrastructure, if you're not
carefully guided by the architecture you're building against, and the
possibilities it offers. The original po... (more)
Whatever your innermost feelings about the < and > symbols, and however
fondly you remember debugging network infrastructures with nothing more than
a LAN sniffer and an uncanny ability to interpret 4k blocks of hex, it is
fairly safe to say that Web services are here to stay. With the industry-wide
support for the concept, and corresponding legions of emerging and released
standards, they aren't going anywhere soon.
One raft of Web service standards that is currently a little closer to the
dock than many is that discussing the concept of cohesions, or business
transactions. On ... (more)