Open Source Java Profiler

Hello Friends,

For those who are interested in Open Source Java Profiling tool.

Introduction

Jensor is a light-weight, low-overhead Java profiler written entirely in Java. Jensor is built on ByteCode Instrumentation (BCI) technology. Jensor provides innovative analysis techniques that help to detect and eliminate bottlenecks in Java applications. More interesting modules are as follows

* Tagging Engine
Allows breakup of data by user-defined tags. Tags can be created to view a business or technical or both perspectives. Tagging Engine thus provides for Business as well as Technical analysis based on the same underlying data.
* JVM Replay
Provides animated display of events that occured in the JVM. The replay thus creates a time and space perspective of methods executed in the JVM. This feature is useful in debugging reliability of Java applications.
* Pattern Analysis
Jensor discovers method call patterns based on the call graph sequence. Optimizing a pattern as opposed to a method provides cascading performance advantages across entire JVM.


http://jensor.sourceforge.net/

Open Source Network Profiler

Hello Friends,
Hope many of you might know about this network profiler which is open source tool developed by TCS Performance Engineering Research Center.

Introductory Information

WANem is a Wide Area Network Emulator, meant to provide a real experience of a Wide Area Network/Internet, during application development / testing over a LAN environment. Typically application developers develop applications on a LAN while the intended purpose for the same could be, clients accessing the same over the WAN or even the Internet. WANem thus allows the application development team to setup a transparent application gateway which can be used to simulate WAN characteristics like Network delay, Packet loss, Packet corruption, Disconnections, Packet re-ordering, Jitter, etc. WANem can be used to simulate Wide Area Network conditions for Data/Voice traffic and is released under the widely acceptable GPL v2 license. WANem thus provides emulation of Wide Area Network characteristics and thus allows data/voice applications to be tested in a realistic WAN environment before they are moved into production at an affordable cost. WANem is built on top of other FLOSS[Free Libre and OpenSource] components and like other intelligent FLOSS projects has chosen not to re-invent the wheel as much as possible.

For more details....please go through

http://wanem.sourceforge.net/

HTTP 1.1 : Caching in HTTP

Hello Friends,
I found an article on HTTP Caching which seems to be useful. I have copied some portion of the article for your reference.

HTTP is typically used for distributed information systems, where performance can be improved by the use of response caches. The HTTP/1.1 protocol includes a number of elements intended to make caching work as well as possible. Because these elements are inextricable from other aspects of the protocol, and because they interact with each other, it is useful to describe the basic caching design of HTTP separately from the detailed descriptions of methods, headers, response codes, etc.

Caching would be useless if it did not significantly improve performance. The goal of caching in HTTP/1.1 is to eliminate the need to send requests in many cases, and to eliminate the need to send full responses in many other cases. The former reduces the number of network round-trips required for many operations; we use an "expiration" mechanism for this purpose (see section 13.2). The latter reduces network bandwidth requirements; we use a "validation" mechanism for this purpose (see section 13.3).

For more details, please go through this link
http://www.w3.org/Protocols/rfc2616/rfc2616-sec13.html

Why doesn't free memory go down on Linux?

Hello Friends,

I have a Linux OS with a java application using 2 GB on a whole and 1.5 GB Memory for oracle database on a 8 GB RAM machine. I am in a situation where i see free memory to be very low i.e. just 35 MB. I had a look at all the available processes but none of the processes are consuming so much memory which is missing. Do you think it is bug? No, it is a feature provided in Redhat Linux.

You can find a good explanation about the situation i have explained above in the below article.

http://sourcefrog.net/weblog/software/linux-kernel/free-mem.html

Details on LoadRunner Certification

http://learnloadrunner.com/introduction/new-features-in-loadrunner-95/

from Learn LoadRunner by Ankur

Since the acquisition of Mercury by HP, there is a lot of confusion among LoadRunner folks about the certification exam offered by HP for LoadRunner. Following is the info I was able to gather for LoadRunner certification from various sources. Trust it would be useful for you all.

LoadRunner exam which earlier used to be CPS [Beginner Level] and CPC [Expert Level] now comes under the heading of AIS HP Performance Center v9 and ASE HP Performance Center v9 respectively. HP Certifications.

To register for the exam, you need:

• The exam name and number (HP0-xxx)
• Your HP Student ID : Can be simply obtained by filling in your personal details.
• Your Prometric Testing ID : HP has partnered with a third party, Prometric to conduct certification exams. Prometric Id is a unique id assigned to you when you register for the exam. This id is also used to maintain your testing history with Prometric.
• Method of payment : The accepted mode of payment is credit card (AMEX, MasterCard, or Visa) or by using a voucher number, or by promotional code. They do not accept payment by company or personal check.

AIS -HP Performance Center v9 : To achieve this credential you need to pass 1 core exam and 1 elective exam.

Core Exam is “HP Virtual User Generator Software Exam”

• Exam #: HP0-M19
• Details, sample questions/ Exam preparation guide can be found here
• Registration details can be found here
• Test fees range from US$60.00 to US$150.00. Details here
• You can also register for –optional– supporting course “VuGen 9.0 Scripting for the web“. It is an instruction led course spanning 2 days. They offer this course for EMEA, APAC and US regions. There is one more option there for organizations wanting to arrange training in campus.

Elective exam is “HP LoadRunner Software Exam”

• Exam #: HP0-M18
• Details, sample questions/Exam preparation guide can be found here
• Registration details can be found here
• Test fees range from US$60.00 to US$150.00. Details here
• You can also register for –optional– supporting course “Fundamentals of LoadRunner 9.0“. It is an instruction led course spanning 2 days. Again, they offer this course for EMEA, APAC and US regions. There is one more option there for organizations wanting to arrange training in campus.

ASE- HP Performance Center v9 : To achieve this credential you need to pass 2 core exams.

Core Exam 1 is “Scripting using HP Virtual User Generator Software”

• Exam #: HP0-M83
• Details, sample questions/ Exam preparation guide can be found here
• Registration details can be found here
• Test fees vary according to region and local currencies. Details here. There is a slight change to the “method of payments” requirements as mentioned on top. Since this is a performance based exams they don’t accept exam vouchers.
• You can also register for –optional– supporting course “VuGen 9.0 Scripting for the web“. It is an instruction led course spanning 2 days. They offer this course for EMEA, APAC and US regions. There is one more option there for organizations wanting to arrange training in campus.

Core Exam 2 is “Performance Testing using HP LoadRunner Software”

• Exam #: HP0-M84
• Details, sample questions/Exam preparation guide can be found here
• Registration details can be found here
• Test fees vary according to region and local currencies. Details here. There is a slight change to the “method of payments” requirements as mentioned on top. Since this is a performance based exams they don’t accept exam vouchers.
• You can also register for –optional– supporting course “Fundamentals of LoadRunner 9.0“. It is an instruction led course spanning 2 days. Again, they offer this course for EMEA, APAC and US regions. There is one more option there for organizations wanting to arrange training in campus.

To get practice loadrunner certification papers, you can refer pass4sure. >From what I have heard, their papers are quite good. They are offering a 10% discount on the purchase if you use the promo code learnqtp.

All The Best!

Please let me know, if you would like to add some more info above OR if you wish to share your LR certification experience.

Everything you wanted to find about LoadRunner

Everything you wanted to find about LoadRunner, but didn't know the URL

http://www.communities.hp.com/online/blogs/loadrunner/archive/2009/05/06/89411.aspx

by mark.tomlinson

Courtesy: Rupesh Garg

Recently I've had some inquiries about finding all the information available in the entire universe about HP LoadRunner, specifically stating that it's very common to get "not found" as a return to results. So, I thought I'd take a few minutes of my generous free time to list the main links to find the official (and some unofficial) links to LoadRunner information on the web.

Let's start with the Hewlett-Packard website - which can just seem like the deepest jungles in the Amazon where you will find that Google does a better job searching and indexing our site that we do.
The main concern about the URLs on the HP website is that they appear to be very long and cryptic and often look to be dynamic strings.
So, with special thanks to our really good friends at Google, here are some very handy links to find LoadRunner information in the www.hp.com website:

· Google Advanced Search for "LoadRunner" on hp.com

· The main LoadRunner "Home Page" on hp.com (just search for BTO LoadRunner)

· Download for the LoadRunner v9.5 Evaluation (HP Passport login required)

· My own LoadRunner blog on the HP Communities site

· LoadRunner overview in a Flash-based movie (on www.youtube.com)

· HP Media Center & Library (link to webinars, videos, demos and podcasts)

· Training Courses for LoadRunner (newly updated)

· HP's IT Resource Center (forums, knowledgebase, downloads ,etc.)

· HP Support…including Submitting and Tracking your SR's and Enhancement Requests

· LoadRunner Patches and Product Manuals (HP Passport login required)

· HP Software Customer Connection Portal and Presentation (HP Passport login required)

Of course, there's all kinds of external sites - ranging from interactive forums, to FAQ's and answers to every possible interviewing question that you might get asked (I remind you it is unethical to cheat on interviews) and there are some quite large communities of LoadRunner gurus out there. Here's a few forums and blogs that I know, love and use daily:

· LoadRunner Google Group - moderated by Dmitry Motevich

· LoadRunner @ Yahoo! Groups -moderated by Mark, James, Matt and Suresh

· LoadRunner Facebook Group - moderated by Kiran Badi

· The new LoadRunner Social Network (on Ning.com)

· LoadRunner on LinkedIn professional network - moderated by Kiran Badi

· LoadRunner @ SQAForums - moderated by JakeBrake, TedZlat, AJ, James Pulley and Terri C

· LoadRunnerTNT – a dynamite site hosted by Hwee Seong Tan

And a posting like this should also include some of the key individual contributors to the LoadRunner performance testing and performance engineering discipline - our leaders and true gurus:

· Dmitry Motevich - a great blog about performance testing and 40 other top blogs

· Alexander Podelko - A Personal Site about Performance Engineering

· Scott Barber - founder of PerfTestPlus

· Wilson Mar - more information than you ever cared to know about LoadRunner

· Ben Simo (a.k.a. Quality Frog) founder of the Questioning Software site

· James Pulley - excellent resources for performance engineering

· Scott Moore - about to launch a new version of the LoadTester website

Although it may seem obvious that I'm just posting a huge bunch of links to get click-throughs on this blog, I honestly must tell you that was not my intention. I have heard from numerous customers that there just isn't the same community of LoadRunner users and engineers out there - like we used to have in the Mercury knowledge base. Hopefully you'll find these links helpful and lasting - people and places you can trust will always have great information about LoadRunner and performance testing.

(note: updated on 3/9/2009…to accurately indicate affiliation for the individuals listed.)

Unix Performance Data Analysis

Hello Folks,

I have found an interesting article on Unix Peformance Data Analysis. I found this to be very good.

www.srmassoc.com/cmg00unix.pdf

HOWTO Monitor Unix Resources using LoadRunner!

Hello Folks,

I found a good article which explains in detail on How to Monitor Unix Resources using LoadRunner.

http://commonlrissues.blogspot.com/2009/03/how-to-monitor-unix-resources-from.html

Dtrace Links!

Hello Friends,

A good website which has lot of D-trace references suggested by the Author. I found it good and interesting.

http://uadmin.blogspot.com/2005/03/dtrace-links.html

Optimizing Windows System Performance!

A good article which has performance accepted values against each and every performance counter in Windows OS.

http://support.microsoft.com/kb/146005