JMeter

JMeter is a desktop application, designed to test and measure the performance and functional behavior of client/server applications. JMeter works by acting as the "client side" of a "client/server" application.


It measures response time and all other server resources such as CPU loads, memory usage, and resource usage. JMeter is used to load-test FTP servers, database servers, and Java Servlets and objects. Today, it has been widely accepted as a performance testing tool for web applications.

The Features—What JMeter Can Do for You

• Performance testing of HTTP and FTP servers, and database queries
• 100% Java-based
• Efficient GUI (Java Swing) design
• Caching of test results

The basic elements of a JMeter include: Thread Group, Listeners, and Samplers. 

The Thread Group element simulates a group of users, which contains at least one user. As a Sampler element makes requests to the target server, a Listener element captures the response data or page following each request.

The Look-How-Easy-to-Use GUI

• Thread Group—each thread simulates a single user. All elements of a test plan must be under a thread group.
• Listeners—Provide access to the information gathered by JMeter about the test cases while JMeter runs.
• Controllers—Samplers tell JMeter to send requests to a server, while Logical Controllers let you customize its logic.
• Timers—Allow JMeter to delay between each request that a thread makes.
• Assertions—Allow you to "test" that your application is returning the results you expect it to.
• Configuration Elements—Working closely with a Sampler, these can add to or modify requests.

Once JMeter runs, you will see two elements, Test Plan and WorkBench,

A Test Plan describes a series of steps JMeter will execute once the Test Plan runs, while a WorkBench functions as a temporary workspace to store test elements.

Automated Testing

Test automation is the use of software to control the execution of tests, the comparison of actual outcomes to predicted outcomes, the setting up of test preconditions, and other test control, and test reporting functions.

Why Automate Testing?

Manual Testing costs too much, takes too much time, does not help them build the product.

Can we do without automation? Yes, of course—if time is abundant and your client (or boss) is NOT on your tail for the application's next release.

Automated testing IS NOT a total replacement for manual testing.

To Automate or Not to Automate.

• Pick a good time to start automating.
• Not all testing approaches are suitable to automate.

1. Suitable: Acceptance, Compatibility, Load, Volume or Capacity, Performance and Reliability, Structural testing, Regression, Exception or Negative testing.
2. Not suitable: Installation and setup, Configuration and Compatibility, Documentation and help, Error handling and Recovery, Localization, Usability, and any other that relies heavily on human judgment.

• Make automation only a supplement to a testing project.
• Do some comparison of Automated vs. Manual Testing.

How Much Does it Cost?

The total cost needs to consider the costs of numerous resources undertaking a testing project.

Person hours to test

Bugs found by the customers are much more expensive than if the same bugs are found during development.

Rex Black's cost of testing—no testing, manual testing and automated testing. 

Automation gives the client higher return on investment (ROI) than manual testing, while no testing at all brings no benefit in the long haul.

Capacity Planning in Performance Testing

Capacity Planning is divided as - Server side and Network side.

Server Capacity Planning means to determine server hardware resources required to provide the desired levels of service for a given workload mix for the least cost.

Types Capacity Planning:

• Capacity benchmarking.
• Capacity trending.
• Capacity modeling.

Benchmarking, or load testing, is perhaps the most common, but also the most expensive. The idea is, you set up a configuration and then throw traffic at it to see how it performs. To do this right, you need access to a fully-configured version of the target system.


Linear trend analysis and statistical approaches to trending can provide quick and dirty ways to predict when you will need to do something about performance, but they don’t tell you what you should do to optimally respond.


That leaves modeling, which comes in a couple flavors: simulation and analytic modeling. Simulation modeling can be very versatile and accurate, but requires a great deal of set up effort and time. Analytic modeling is fast and is potentially very accurate as well. The beauty of modeling is that you can “test” various proposed solutions to a problem without actually implementing them. This can save a lot of time and money.

QPST - Qualcomm Product Support Tools

QPST is software package used for phones based on Qualcomm chips:
UMTS-based phones EF81, SXG75, SFG75, E81 and other (EF82, SL91, etc.).

QPST software includes:
QPST Configuration - COM-port selection to work with phone.
EFS Explorer - file manager for phone file system.
Display Capture - screen capture utility for Java-games and video playing.
FTM Application - front end testing.
RF Calibration - front end calibration.
RF NV Item Manager - NV-memory manager (EEPROM).
RL Editor - roaming list settings.
Service Programming - different phone settings.
Software Download - phone flasher.
QCNView - .QCN files viewer, generated by Software Download (Backup menu).
DMProxyWin - QPST ports translation server. Allows to connect to the current phone from another device, which connected to Internet using QPST and DMProxyWin.
Gang Flash Image Application - creates firmware and file system image to use in programmer such as Data I/O ProLINE RoadRunner or Data I/O FlashPAK.

Mobile Application Testing

Testing is regarded as last priority while developing an App. Not for all Apps. Testing takes time. Comprehensive testing takes more time if we use conventional methods. Many orgs use Testing Matrix for Mobile Apps. However, testing methods for mobile apps is still the same. Traditional testing methods are outdated, inefficient and  ineffective for mobile apps. So what we do? We test less and hope for the best.

The challenges of Mobile App Testing: Of course,Users, Bugs, and Money.
Users does download Apps from Stores, but if they come out buggy, then they throw it away and never use it. Only non-buggy Apps stay on their Handsets. So developers need to test their App on Handset, OS, Browser, Carrier, Location, etc. So what companies do: They do following:

• In-House Testing.
• Outsource Testing.
• Simulators / Emulators.
• Beta Testers.

Testing is very important for Mobile Apps. 

Linux SSH Tricks

To see debug lines of ssh session login, use below command:
#ssh -v <IP>


SSH session toggle between remotehost and localhost:
Localhost$ ssh remotehost
Remotehost$ ~^Z [suspend ssh]
[1]+ Stopped ssh <IP>
Localhost$ fg %1
Remotehost$

Linux Commands

Create directory and give permisson in a go.
# mkdir /tmp/test1 -v -m 1777

Environment variable $CDPATH
It lets you define some path to look for when moving with cd command.
# export CDPATH = . : / : ~/
# cd usr
/usr
# cd Desktop
/home/viku/Desktop

Hardware info:
# dmidecode --type memory
# dmidecode --type bios
# dmidecode --type cache
# dmidecode --type processor
so on....

Find all files with extension .txt or .jpg
#find . -type f -inode "*.txt." -or -inode "*.jpg"

Find all files except hidden files
#find . -type f -inode "*.txt." ! ".*"


Append text at end of file, use >> operator.
Append text at beginning of file.
#echo "text" |cat - file.txt > /tmp/out && mv /tmp/out file.txt

Check whether an alias is assigned to a command
#type ls

Revert alias to original
#unalias ls

Restrict alias effect and see the native command.
# command ls
# \ls
# "ls"

Diff and Patch
#diff -c oldfile newfile  > temp.patch
#patch < temp.patch