Andrey Mikhalchuk’s Blog

If you don’t hear about it FPV Japan is a small device that records standard definition video from analog sources. This is an indispensable device for FPV RC pilots and the ones who want to digitize old analog video tapes. I fall into both categories, but unfortunately the video cable from my device got burned in an accidental fire that also cause my video blog RTFMS to halt for a really long time. Long sad story …

Anyways, I was repairing the cable recently and decided to pinout it since there seems to be no information in the internet about this very custom cable. So in case if you want to build your own cable here is how it is interconnected:

Managed Snippets Plugin for Jive is awesome. It allows administrators to define sort of “macros” that can be reused on a Jive portal. The best part is that it allows to workaround the regular limitation for using javascript and HTML tags. Yes, that’s right, you can use Javascript, IFRAMEs and all HTML tags in the managed snippets. This is a very elegant way to allow users use limited and well-managed Javascript without exposing site to XSS attacks.

Originally this plugin was only available for place types only. For instance you can insert it via Customize->Other->Managed Snippets menu into a group overview and include a google map for instance. However as of 1.0.3.0 you can also use it in user posts, documents, virtually any objects. Here is how you can do it and a few caveats:

The default login for the admin user for the JBoss Enterprise Application Platform (EAP) 5.2.1 and other v5 versions is “admin”. The passwords is obviously also “admin”. However if you try those right after the installation they won’t work, because you need to patch two files:


make: /opt/local/bin/ginstall: No such file or directory

This happened to me while running bundle install on json v1.7.7.
The fix is

# sudo if necessary
ln -s /usr/bin/install /opt/local/bin/ginstall


Overall the installation is pretty smooth, just follow the instructions on Oracle website.

There are two minor hiccups though:
1. cannot touch `/var/lock/subsys/listener’: No such file or directory

This error is cause by the fact there is no /var/lock/subsys directory in some Linux distros, so you need to create one. Before you run “/etc/init.d/oracle-xe configure” run

mkdir /var/lock/subsys


2. The second one is trickier. When you run the configuration wizard it fails while configuring the database and the log files contain something like

==> cloneDBCreation.log < ==
alter system disable restricted session
*
ERROR at line 1:
ORA-01034: ORACLE not available
Process ID: 0
Session ID: 0 Serial number: 0


As you probably read in my other post, OPA is a great alternative to the Oracle Business Rules (OBR) as all the business logic could be exposed via web services. Unfortunately Oracle didn’t leave us much documentation about how to do that. So if you’re wondering how do you call OPA determinations server, here is an example:

Port mapping is a great feature that allows you to make almost any remote network service to work like it is running on your computer. Most people use specialized software to make it work, however there is a built-it Windows command that allows you to do exactly the same thing. Fire up windows command shell (Start->Run->cmd) and run this command:

Subj,
It’s buggy and misleading. You will do better by installing Oracle Virtualbox (free) with Linux (free) and running valgrind (free) in the virtual machine.

It looks like not many people know about this, but Oracle actually has two business rule engines. One is called OBR (Oracle Business Rules) and it is bundled with SOA suite. The other one has less meaningful name OPA (Oracle Policy Automation) and at the first glace serves totally different purpose of generating a nice web questionnaire from a word doc with specs. Fortunately the company that originally developed OPA (RuleRust/Haley) was cleaver about decomposing functionality and Oracle inherited this cleaver design after purchasing Haley.

OPA consists of three parts:
- Determinations Engine – a library you can use in your .net or java program, does all the business logic evaluation
- Web Determinations – the part that runs the web surveys and uses the DE for making decisions
- Determinations Server – that’s the part that wraps the DE and exposes it in the form of a web service. Essentially it does the same thing OBR does.

The way OPA works is
- you write your business rules specs using more-or-less plain english in a word or excel document
- markup your rules with OPA toolbar (part of MS office only, sorry)
- compile your rules using the same OPA toolbar
- build a package containing rules from multiple source using Oracle Policy Modeling – a standalone tool, part of OPA package. Also windows only, also sorry.
- you upload the package to the application server
Since the package contains the DE all your business logic becomes a web service you can consume just like OBR.

This is all cool and in fact OPA works much faster than OBR in 98% of cases, supports bulk processing and overall awesome. But it’s not quite as friendly as OBR in terms of editing the business rules, right? BPM Workspace doesn’t see these rules and you can’t modify the rules in runtime.

Fortunately there is a way to make it more friendly. Here’s how…

I’m working on multiple machines under multiple accounts on the same project and using git to sync between the codebases. The program by its nature has to run under root account, so no wonder at some point permissions got screwed up and I’ve got stuck with this error:

! [remote rejected] master -> master (n/a (unpacker error))

The solution is quite simple though requires access to the master repo: