Adjusting wireless for laptop hp 6710b

it's to be set ATrpms.net repository(look at http://www.osresources.com/11_6_en.html)

then in command line of terminal it's to be invoked :

yum install ipw3945-kmdl-`uname -r` ipw3945


Setup java for CentOS 5

Download needed java distributive.
If you want to have two jvm for i386 and x64 you have to download non rpm package.

1. login by root user
2. go to /usr/java/
3. run jdk-XXX-linux-XXX.bin
4. add symbolic links determining default jvm by using command alternatives

e.g.

/usr/sbin/alternatives --install /usr/bin/java java /usr/java/jdk1.5.0_16_x64/bin/java 3


4.choose default by using command alternatives
e.g.

/usr/sbin/alternatives --config java


e.g.

[root@localhost jdk1.5.0_16_x64]# /usr/sbin/alternatives --config java

There are 3 programs which provide 'java'.

Selection Command
-----------------------------------------------
* 1 /usr/lib/jvm/jre-1.4.2-gcj/bin/java
+ 2 /usr/java/jdk1.5.0_16/bin/java
3 /usr/java/jdk1.5.0_16_x64/bin/java

Enter to keep the current selection[+], or type selection number: 3


Checking...

[root@localhost jdk1.5.0_16_x64]# java -version
java version "1.5.0_16"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_16-b02)
Java HotSpot(TM) 64-Bit Server VM (build 1.5.0_16-b02, mixed mode)




Enjoy :)

Performance tuning Java performance tools

Profiling tools

1. Yourkit
http://www.yourkit.com/


Thread Stack Dump Viewer

1. Samurai Thread Stack Dump Viewer
http://yusuke.homeip.net/samurai/en/index.html

2. IBM Thread and Monitor Dump Analyzer for Java
http://www.alphaworks.ibm.com/tech/jca

Load Testing Tools

1. Jmeter
http://jakarta.apache.org/jmeter

Hermes JMS - Open Source JMS Console

HermesJMS is tools that helps to trace jms messages state.


Quick setup for BEA 10.2 and Hermes v1.12 on Linux


1. Open the /bin/hermes.sh in your favorite editor. Add path to your JAVA_HOME after comment "# Setup the Java VM".
e.g.

JAVA_HOME="/data/bin/jdk1.6.0_03"
export JAVA_HOME"


Note: Hermes IS built with jvm 1.6 therefore you have to use jvm version 1.6 for running one, but
BEA 10.2 is run with jvm 1.5. This combination create some problem with classLoader look here ,the solve is using -Dsun.lang.ClassLoader.allowArraySyntax=true. Add it in jvm running command


2. Launch Hermes by calling the hermes.sh
3. Create new JMS session.

at first you have to set provider :



It's not add this library in class path therefore You have to add it in classpath of jvm.
e.g.
LOCALCLASSPATH=$LOCALCLASSPATH:/data/beas/bea102_32/wlserver_10.0/server/lib/weblogic.jar
export LOCALCLASSPATH


then go back to tab "sessions" and configure it. Look at the picture below




Destinations is not needed to fill. They fill automatically by using "Discover queues and topics from the provider"


4.Choose one of destination then create new watch Actions>Watch>New Watchs..


resources:
1. http://dev2dev.bea.com/cs/user/blog?file=/blog/jbayer/archive/2008/01/hermes_jms_open.html
2. http://www.hermesjms.com/confluence/display/HJMS/Home

Some useful commands for working with Solaris 5

1. Reading info about running process:

$ ps -ef


2. Checking check sum

$ digest -a md5 -v /bin/ls
md5 (/bin/ls) = b57e173220af4b919f1d4bef9db11482


3. Show list dynamic dependencies of executable files or
   shared objects


$ ldd -v solaris-x86-32/libyjpagent.so


4. Look at ports of processes


pfiles `ptree | awk '{print $1}'` | egrep '^[0-9]|port:'
pfiles PID | egrep '^[0-9]|port:'


Performance issues

In general application has three kind of performance problems :

- throughput of application is low;
- the application is inclined to memory leak;
- the application is inclined to deadlock.

Before starting you have to define requirement for application. You have to define what is acceptable throughput and what working load is expected.

Throughput of application is detected by using jmeter. JMeter is used as a load testing tool for analyzing and measuring the performance of a variety of services, with a focus on web applications. You should create test scenario for imitation loading of application and tunning environment like production. The result of test is set of measuring datum.

Inclining application to memory leak is detected by using jvm abilities or profiling tools(Yourkit). For reproducing memory leak you have to load application, but the load should be little bit more then defined in the requirement. The result is set of memory snapshots.

Inclining application to deadlock is detecting by using abilities your OS. You should load application,you can use jmeter for it ,and make thread snapshot throughout testing. The result is set of thread snapshots.

“Server crashed “

At first time you should know what happened with the process of server.

- if the process was died :

collect all logs what do you have

The possible reasons : crash jvm, somebody/something kills process.

- if the process is live , but the server&application don't answer :


You should try to made thread dumps and collect all logs what do you have

The possible reasons : memory leak or deadlock.