Strange Loops

ActiveMQ Gotcha!

We were doing a trial deploy of our brand new java service to the production host yesterday. The service had started up everywhere else so far

Of course it didn't start up on this production host. In the logs was a stack trace that included this error message:

cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'amq:broker'.

What caused this problem? This production host was firewalling off connections to activemq.apache.org. This host was serving a XSD file which was required to validate the XML namespace we have used.

I'm thinking WTF! Seriously? Why wasn't the XSD file deployed with jars?

The simplest solution/workaround was to take  http://activemq.apache.org/schema/core/activemq-core-5.2.0.xsd and make it http://activemq.apache.org/schema/core/activemq-core.xsd in our XML file. When validating the XML file, it'll use a version of the file available within the activemq jars.

Dropping the version causes Eclipse to complain but that's another problem (and another google search).

Compiling Jython Scripts to Java Class Files

Had this little snippet of code lying around my directory.

Didn't know what to do with it. It was somewhat useful. We were trying to compile unit tests written in jython for our java code. The jythonc tool had gone away in jython 2.5 but an ant task (JythoncAntTask) in 2.5 still did that. I did a little bit of code spelunking and extracted the code snippet seen above. I don't know the reasons for removal of jythonc but I suspect this usage is not generally supported by the jython maintainers. Please don't complain if this doesn't work for you. We went with another approach for getting our jython unit test to run.

One should be able to compile it from the command line. You'll need the jython.jar to compile it. To run this against a jython script, I threw together a little shell script.

This post was also a little experiment in embedding code samples into my blog posts. The trick is the script tags provided by gist do not work with the preview/rich text mode provided by typepad. They only work after the blog entry has been published. Other than this little gotcha,  Gist is a nice tool for collecting code snippets.

Obama’s 2011 Budget Proposal: How It’s Spent - Interactive Graphic - NYTimes.com

Published: February 1, 2010 Obama’s 2011 Budget Proposal: How It’s SpentRectangles in the chart are sized according to the amount of spending for that category. Color shows the change in spending from 2010.

via www.nytimes.com

Nice visualization of the budget. No surprise what makes up the biggest amount.

Netbook Part Deux

Over the holidays, I got myself a Lenovo IdeaPad S10-2. Initially the plan was to make it into a Hackintosh but since I got the machine working well I've decided to not go that route. Right now, I'm very pleased dual booting Windows XP with the Ubuntu 9.10 Netbook Remix. 

I was an early Netbook early adopter. I purchased an Asus EEE in Feb 2008. One of the first entries into the Netbook market. We were going to Maui for a week and the EEE seemed like a great travelling companion. The small form factor made it easy to pack and the low cost made the potential lost on the trip more acceptable.

However after the trip, I'm promptly sold it. The Asus EEE and Lenovo IdeaPad have roughly the same dimensions but the deal breaker for the Asus EEE was the tiny keyboard. There were fairly large speakers (in relation to the rest of the EEE) to the left and right of the keyboard. This made the keyboard even smaller than it had to be. The IdeaPad does not have the same issue. Though smallish, I'm fairly comfortable touch typing this entry on the IdeaPad's keyboard. 

By default, Windows XP is installed and required for any future servicing or restoring to factory condition. I'm more of a Mac and Linux person so I had to find tools/applications to make Windows acceptable and integrate with my other equipment. I'm pleased with what I've found and actually find the experience relatively painless.

1. Removed the antivirus program

I should not do this but after uninstalling the Norton antivirus program, the IdeaPad experienced a fairly nice performance boost. I don't use IE or Outlook so most infection vectors are closed off. I still have to be extra careful about what I install on this machine though.

2. Chrome and Firefox

I was impressed with my brief usage of Chrome in early 2009, it was fast and I liked its sandboxing architecture that made it resistant to attacks (see this). On the IdeaPad, it's my default browser. 

Firefox is also installed because they are too many useful Firefox add ons. I have to say the 3.6 version has been pretty good on my Mac. For day to day browsing, Safari used to be noticeably faster but I don't notice a difference anymore.

3. xmarks

xmarks is a bookmark synchronization tool. It synchronizes my bookmarks across my browsers on all my machines. When I had one machine, I never understood the use of xmarks. With multiple browsers and machines, I love having the ability to manage all my bookmarks from one central location.

4. Dropbox

I use dropbox for sharing and synchronizing files across my multiple machines. It also version files that you put into it (effectively serving as a backup). Any documents I'm working can be accessed from any of my machines.

5. Evernote

I use evernote for managing my notes across all my devices. 

6. Notepad++

notepad++ is a huge improvement over the regular notepad. Has a bunch of useful programming specific features (e.g. line numbering, syntax coloring) and does not have a problem with unix style line endings (where the regular notepad puts the entire file on a single line)

7. Ubuntu 9.10 Netbook Remix

Used Wubi to install Ubuntu. Sometimes I just need access to Linux. No repartitioning of the hard drive is necessary. Wubi installs Ubuntu on the windows partition of the hard drive (at the cost of slower disk performance which doesn't really matter in this situation).

8. Python

It's what I use these days for small projects. In the past, I liked Strawberry Perl and I would used it again if the need arises.

You'll also want easy_install to get new libraries.

9. Git, Putty

I need access to my git repositories since that's where my code is. Used TortoiseGIT (and it's dependency msysgit) for that. Works great for my simple usage. No major complaints. 

putty is the only game on windows for ssh'ing into my remote hosts.

3 + 4 + 5 + 9 form a common theme, they are tools I use for managing information/code I collect.

10. miro, songbird

For listening to podcasts and other digital media. This is one area I need to work on more. Figuring out how to access the digital media stored on my other computers.

11. External mouse

I've never liked trackpads so an external mouse eases that frustration. Nothing complicated. Just got myself a cheap (< $20), wireless optical mouse. This one fits the bill pretty well.

My new IPad

The Lenovo IdeaPad S10-2 that I picked up on my trip to Singapore at the beginning of December. This one is a wifi only version. There is a 3G option available (based on what the user manual tells me). I've regularly taken this handy little device to the coffee shop whenever I want to catch up on my RSS feeds. The 10 inch display and regular keyboard make web browsing easier than on the iPhone. It evens come with a cute little pink carrying case.

This IPad is not be confused with this. :)

Reflection

On my long run yesterday, I was able to reflect on the events from the last seven days. I was trying to understand what this experience would teach me. This has been a major wake up call. 

I thought through a lot but I kept coming back to 3 main ideas:

1. Life is too short to be anything but happy.

2. Someday might never come. 

3. What we leave behind is not as important as how we've lived.

It's not clear how I'll use these ideas since my mind is still in a fog of sadness, anger and fatigue. Hopefully the next couple of days will help to make things clearer.

Numb

I'm numb tonight. I keep thinking about what has happened in the last day. I kept coming back to this quote spoken by one of my favorite fictional characters:

Someone once told me that time was a predator that stalked us all our lives, but I rather believe that time is a companion who goes with us on the journey and reminds us to cherish every moment because they'll never come again. What we leave behind is not as important as how we've lived. - Jean Luc Picard, Generations

Happy New Year!

Happy New Year! I know it's 10 days into the new year but I have not gotten around to posting on my blog yet. One of my resolutions for the new year is to post more consistently. Hopefully I hit that goal this year.

2010 is going to be the year of awesomeness! I can feel it.

New Project: CCTV

One little project I'm undertaking is to build a CCTV system for the house. A little background, last Christmas our place got broken into. Among other measures, a CCTV/camera system was something we wanted to install. The requirements are basically to be relatively cheap and preferably with motion detection so the cameras don't need to be turned on constantly.

The biggest cost to the system is likely to be the cameras. For prototyping, I will use an old Ubuntu box and getting one camera to start with. ZoneMinder is the software that will be running on the Ubuntu box.

After doing some research, the D-Link DCS-920 will be the initial camera for prototyping with. It seems to be the best compromise between cost and features. It's wireless and appears to have fairly decent image quality.

Building ØMQ on my Mac

In my plans for world domination, I need messaging software. I wanted to try out ZeroMQ (trying out RabbitMQ is for another weekend). I'm skipping ActiveMQ since we use it at work and I mostly understand what it provides.

Downloaded the tarball and it compiled right out of the box. However when I tried to get it to run with a simple java program I've written, I kept getting this error (this is on Leopard).

dc@feynman:dist$ java -Djava.library.path=/opt/personal/pkg/zmq/lib -classpath lib/Zmq.jar -jar ZmqTest.jar 
Creating ZMQ
Exception in thread "main" java.lang.UnsatisfiedLinkError: /opt/personal/pkg/zmq/lib/libjzmq.1.0.0.dylib: no suitable image found. Did find: /opt/personal/pkg/zmq/lib/libjzmq.1.0.0.dylib: mach-o, but wrong architecture /opt/personal/pkg/zmq/lib/libjzmq.1.0.0.dylib: mach-o, but wrong architecture
 at java.lang.ClassLoader$NativeLibrary.load(Native Method)
 at java.lang.ClassLoader.loadLibrary0(ClassLoader.java:1881)
 at java.lang.ClassLoader.loadLibrary(ClassLoader.java:1805)
 at java.lang.Runtime.loadLibrary0(Runtime.java:823)
 at java.lang.System.loadLibrary(System.java:1045)
 at org.zmq.Zmq.(Zmq.java:25)
 at zmqtest.Main.main(Main.java:15)

As far as I can guess, the JVM I'm using is 64bit so the libraries it loads also need to be compiled as 64bits. To fix this, I had to set the CXXFLAGS environment variable to build 64 bits. This set of steps worked for me.

export CXXFLAGS="-arch x86_64" 
./configure --prefix=/opt/personal/pkg/zmq -with-java
make clean
make
make install

Here's my small java program

package zmqtest;
import org.zmq.Zmq;

public class Main {
 public static void main(String[] args) {
  System.out.println("Creating ZMQ");
  Zmq zmq = new Zmq("localhost");
  System.out.println("Done creating ZMQ");
 }
}