Monthly Archives: April 2014

How #Twitter influenced my life.

It was the 31st of August 2009 at exactly 1 PM that I sent out my first tweet and it read “hmmm… Twitter…”
Today we are nearly 5 years on and we are 7,303* tweets along. I have 417 people who are willing to more or less read what I send out, which is just amazing to me!

* As per April 10, 2014 10:54 AM

I just wanted to step back for a second and reflect on what Twitter did for me, and share this reflection with you.
I remember being very hesitant about starting to tweet. The usual arguments like; “Who ever would wanna know that I was taking a coffee” or “Why would anyone want to know what I saw or did”… I decided to give it a little bit of a go, inspired and with a little peer-pressure by @Tom_Schepers.

The beginning was rusty with not much tweeting going on. Finding my way, looking for inspiration on what to communicate.
Somehow it really took off with my visit to the Norwegian Oracle User Group #ougn13. During this event I took it upon me to share a little something of every session I visited or inspiring meetings I encountered.
From that point on, I gradually started tweeting some more, staying in touch with the people that inspired me personally, and somehow, most of them appeared to be in the field of #Oracle.

From here one, I started to “TKnow” a number of people, rather than really know them. This means that there are folks out there I have talked with before I have ever met them in real life. Nice examples include @oraclebase, @ultan or even @pfierens, my partner in crime in many events and fellow member of the #Pragmas.
There are even people I value highly whom I have never even met, like for instance @MathijsBruggink or @annsjokvist.

Getting to the point… how #Twitter influenced my life.
Twitter has given me a way to communicate and stay in touch with friends and peers all over the world. Share serious contemplations, joke around or just socialize.
It has played a part in enabling me to startup an international career, in connecting people and visions in and around IT in general and #Oracle specifically.
Such a simple tool, and for any non believers, please give it a try, it could also change your life.

Idempotent, a parameter with adverse effect

To create and distribute, since long, we have had the power of Oracle Reports at our fingertips. These same report definitions can still be used successfully nowadays.

With all the technical changes over the years, we’ve come to a point where Oracle Reports Server, is now part of Oracle Fusion Middleware proposition. It is a (small) container, application or component of this software stack, where it is loaded in an application server and thus deployed.
Although this takes Oracle Reports Server into the modern age, it adds a lot of complexity for smaller implementations, a lot of tweaking and tuning to get it all running smoothly. One of these examples I would like to address here…

We were faced with a situation where we were running a report, an e-mail distribution report, sending out specific information to a multitude of e-mail addresses. And there was this situation where this report was run on a system, which was somewhat overloaded. This is not good, but not always completely predictable or avoidable.
For this report to run very long, actually was not a big issue as these individual e-mails were just informational and not time-bound on a minute-scale.

The problems started when we were getting word that some recipients of these e-mails were getting multitudes of copies of these e-mails! Which was sloppy at best…
Wait… multitudes of e-mail from a job which is running slow… That’s odd, they should be getting either a late e-mail or perhaps no e-mail at all! Not a lot of e-mails, that is contradictory!

This called for an investigation.

Finally we stumbled across a technology designed to do no harm, I would like to call your attention to idempotence!
Funny thing is, this setting is not part of Oracle Reports Server, but of another component used in this complexity, Oracle HTTP Server (OHS).

  • When set to ON and if the servers do not respond within WLIOTimeoutSecs (new name for HungServerRecoverSecs), the plug-ins fail over.
  • As stated on WikiPedia, an idempotent operation is “that can be applied multiple times without changing the result beyond the initial application

Obviously, this was not the case with our situation! This idempotent operation was applied multiple times and it did change the result far beyond the initial application. Up to 40 e-mails per recipients on one specific occasion.

In effect, what happened, was that the Oracle Report, which was called through a URL, did not complete within WLIOTimeoutSecs, was just restarted. The URL, as it was called to start the process, was called again from withing the Oracle Fusion Middleware Stack, starting a new run of e-mail distribution… over and over again.

We resolved the situation by two completely different actions.

  1. we made sure this operation was not run on a system which was too busy to handle the load
  2. we made sure Oracle Fusion Middleware wouldn’t get the crazy idea to re-run this operation again.

Number two was fixed by the adding of the following instruction to the installation guide (and actually doing this too):

Toggle parameter IdemPotent to ‘off’ in reports_ohs.conf in:


This can be accomplished through the Enterprise Manager

Webtier -> Ohs1 -> Oracle http Server -> Administration -> Advanced Configuration -> Choose a file -> reports_ohs.conf

Add the following line to the body:
## Added <name> <date>
IdemPotent off

Our problems are gone now!