Unix commands help on diagnosing Weblogic problems

While working on diagnosing the Weblogic problems, I found the unix commands help me a lot, here they are:

• Apache error_log files BackEnd errors: grep -r -h --include=error_log Backend . | awk '{print $2 " " $3}'| sort | uniq -c
  
  
• Oracle connections: while true; do netstat -an|grep 1521; netstat -an|grep 1521|wc -l; echo "+++++++++++++++++++"; sleep 4; done;
  
  

Google App Engine for Java Rocks!!!

I signed up GAE yesterday, and the account was activated today. It is time to play with it:
* Create Application ID
* Download and install Eclipse plugin
* Create new Web application
* Deploy application to GAE

Done!!!
It is just so easy.
More will come on this topic.

How to remote debug JMeter?

Want to remote Debug JMeter? Here I show you how I did it?

1. Download JMeter binary package and source package, unzip them into the same directory.
2. Rename the eclipse.classpath file to .classpath and open the project with IDEA.
3. Open a shell, set JVM_ARGS=-Xdebug -Xrunjdwp:transport=dt_socket,server=y,suspend=n,address=5005
4. Start JMeter in the previous shell.
   
5. Setup remote debug in IDEA and start debug.
   

Setup JMeter JMS Publisher Sampler

Even though there are documentations on how to setup and use JMeter JMS publisher sampler, it seems all of them are either inaccurate or out of date. After pulling my hair for almost two hours, I finally made it work. To avoid headache for anybody who want to set up JMeter JMS publisher sampler, I recorded the procedure as following.

We choose ActiveMQ as our JMS provider.

1. Copy activemq-core-5.2.0.jar, jms-1.1.jar, and geronimo-j2ee-management_1.0_spec-1.0.jar into JMeter's lib directory.
2. Create a jndi.properties file and jar it into a jar file, put the jar file into JMeter's lib directory.
3. Confiture the JMS publisher sampler with the following settings in the JMeter GUI.

• Check use jndi.properties
• Connection Factory: ConnectionFactory
• Topic: MyTopic
  
• Number of messages to aggregate: 1

Here is the content of the jndi.properties file:
java.naming.factory.initial=org.apache.activemq.jndi.ActiveMQInitialContextFactory
java.naming.provider.url=tcp://hostname:61616
topic.MyTopic=topic

There are a few catches during the setting up process:
* The ActiveMQInitialContextFactory package name must have the apache.
* ConnectionFactory can not contain any trailing space.
* The Topic JNDI name must be prefixed with topic in the jndi file.
* You must put in the Number Of messages to aggregate, otherwise there will be no messages published.

TeamCity checkout rules

In team city Version Control Settings you can include/exclude the path for checkout.
Here are a few examples:

• I want to checkout only the directories:/project1/testing/watirtests, and /project1/ant, but not anything else under project1:

-:project1
+:project1/testing/watirtests
+:project1/ant

• I want to checkout everything but derectories:/project1/testing/watirtests, and /project1/ant:

+:project1
-:project1/testing/watirtests
-:project1/ant

Python recursive generator to find all the files in a directory

Just for exercise, I programed the following transverse_directory function in python to find out all the files in a directory tree in python, while trying the google treasure hunt - zip:

def transverse_directory(path):
   if os.path.isdir(path):
        for item in os.listdir(path):
            item_path = os.path.abspath(path) + os.sep + item
              for file in tranverse_directory(item_path):
                  yield file
   else:
       yield path

Recursive lambda implementation factorial function in Python

It is easy to implement factorial function use recursive in Python, but how do you implement it by using recursive lambda in Python? Here is my try:

 
fact = lambda n: (n and n-1) and n*fact(n-1) or 1