Categories
Linux Interview questions testing

Symmetric Encryption Vs Asymmetric Encryption

Symmetric Encryption

  • Symmetric encryption is the oldest and best-known technique.
  • A secret key, which can be a number, a word, or just a string of random letters, is applied to the text of a message to change the content in a particular way.This might be as simple as shifting each letter by a number of places in the alphabet.
  • Symmetric encryption uses the identical key to both encrypt and decrypt the data. 
  • As long as both sender and recipient know the secret key, they can encrypt and decrypt all messages that use this key.

Examples of Symmetric Encryption includes: DES, Triple-DES (3DES), IDEA, CAST5, BLOWFISH, TWOFISH.

Asymmetric Encryption

  • This encryption technique is born from the disadvantage of Symmetric Encryption.
  • Asymmetric encryption, in which there are two related keys–a key pair(A public Key and a Private Key). 
  • A public key is made freely available to anyone who might want to send you a message. A second, private key is kept secret, so that only you know it. 
  • Any message (text, binary files, or documents) that are encrypted by using the public key can only be decrypted by applying the same algorithm, but by using the matching private key. 
  • Any message that is encrypted by using the private key can only be decrypted by using the matching public key.

Examples of Asymmetric Encryption includes: RSA, DSA.

Categories
Performance Testing

Known performance issues in Oracle SOA Products and Oracle AIA Foundation Pack for 11g Release 1 (11.1.1.7)

These are Known performance issues in Oracle SOA Products and Oracle AIA Foundation Pack for 11g Release 1 (11.1.1.7):

  • PermGen Space Out-of-Memory Error when Using the Sun JDK
  • Maximum Heap Memory Size Recommendations on Windows 2008 Server
  • Increasing the XA Transaction Timeout Value
  • Inconsistent States for SOA Composite Application Instances in Recovery
  • Google Chrome Browser Limitation on Displaying XML
  • Exception: Internal Error While Activating AIAJMSSERVER (JMS Server)
  • Dequeuer Returns the Same Message in High Concurrency Environments with Oracle Database 11.2
  • Default/Last Active Revision of a Composite Is Not Identified When Retiring All Composites in a Partition.

For more information visit : http://www.oracle.com/technetwork/middleware/docs/aiasoarelnotesps6-1866030.html

Categories
Performance Testing testing

Loadtesting Websphere IBM MQ server using JMETER

 

 About :

For Loadtesting Apache Active MQ , JMS-Point-to-Point sampler in Jmeter will help us. Think that you do not have JNDI settings and no apache activemq for JMS messaging, instead IBM Websphere MQ is in place.  One day your manager is coming and asking you to test IBM MQ using open source testing tool as they do not ready to pay for small scale performance testing.

In that case , here is the steps to use Jmeter to load test IBM Websphere MQ.
The content here is pretty much precious and definitely it will save your valuable time 🙂

  • Below are the Java and MQ jars needed.  Download these jar files and place it under Jmeter’s libext directory. ‘jmeter-jms-skip-jndi-0.0.1.jar‘ is the jar contains the MQ declaration and coding to connect it. You can down it from the URL : ‘http://www.java2s.com/Code/Jar/j/Downloadjmeterjmsskipjndi001jar.htm‘
    • com.ibm.mq.jar
    • org.springframework.beans.jar
    • org.springframework.jms.jar
    • javax.jms.jar
    • jmeter-jms-skip-jndi-0.0.1.jar
    • spring-core.jar
  •  Open Jmeter -> File-> New->TestPlan -> Add Thread Group
  • Under Thread Group add Samplers->JMS Point-to-Point Sampler and configure the parameter. As given in the below Screenshot.
  •  Run Jmeter Script and Enjoy IBM MQ load testing .

MQ1

Categories
Performance Testing

TOP 15 Reasons why you can use jmeter for performance testing

 

  1. Jmeter is an open source tool.
  2. There seem to be more cost saving for MQ ,SOAP,FTP protocols when considering other proprietary tools in the market.
  3. Customized/Specialized reports are given in proprietary tools to attract the end users. Jmeter has simple reports and it will be helpful to analyse the server logs and get into the root cause of the performance issue. So if you do not want Grand UI reports , Jmeter will save more money from you pocket.
  4. User friendly UI.
  5. All the components are pre-built and readily available for use. Even the person who is not much comfortable with coding can understand and script in jmeter.
  6. Test can be executed in NON-GUI mode to save the machine resources.
  7. You can extend or write the new samplers in java and it can be included in jmeter.
  8. You can send the files with the request using simple configuration.
  9. It is easy to run multiple users (1000 User logins in ~2GB system) without worrying license cost.
  10.  Simple and effective session correlation for a web application.
  11. You can run multiple scripts consecutively(One at a time) , also all at a time (concurrently)
  12.  Response time results can be exported to CSV.
  13. Assertions will help to validate the response from the server easily.
  14. You can send JSON string and test JSON response for HTTP request.
  15. Various timers are there to introduce the delay concept
Categories
technews

What’s a cron and crontab?

Cron is a a time-based job scheduler in Unix/Linux environments. Cron can be used to schedule jobs to run periodically at fixed times, dates or intervals.  Crontab is a configuration file that specifies  shell  commands to run periodically on a given schedule.

Users can have their own individual crontab files and often there is a system wide crontab file (usually in /etc or a subdirectory of /etc) that only system administrators can edit.

Crontab format

MIN  HOUR DOM MON DOW <command to execute>

  1. MIN =Minute(0-59)
  2. HOUR =HOUR(0-23)
  3. DOM =Day Of Month(1-31)
  4. MON =Month(1-12)
  5. DOW =Day Of Week(0-6)

cron

How to view crontab entries?

To view current user’s crontab, use “crontab -l“

eg :

cron1

 

 

To view other user’s crontab, login as root and give “crontab -u sam -l”

cron2

 

 

How do I edit crontab entries?

We can issue “crontab -e”  for adding or editing crontab entries.

 

Categories
Performance Testing

Finding the number of lines of unique string in a file for specific duration- Linux

One day , I gone though a scenario where I have to count the number of lines of error string in a file for specific duration in the linux server using single command. I require it as I will be repeating it for multiple iterations of testing cycle.
As I did not have much experience in linux commands , I spent more time in browsing various web pages and finally I was able to join the commands in order to get one line command.

sample

 

 

 

 

 

 

I think this might be useful to many testers like me

Linux command for finding number of lines of unique string in a file for specific duration:
sed -n ‘/2013-12-24 20:20:00/,/2013-12-24 23:59:59 /p’ logfile.log | grep ‘error’ | wc -l

Or you can use this as well for quick view,
grep -i ‘error’ filename.log

Here You can update any string that has to be searched in grep ‘error’

Categories
technews

Ubuntu and Android dual boot developer preview

Ubuntu has announced a preview for developers: Ubuntu on mobile devices can run along side with android, yes your mobile can be dual booted. Ubuntu has informed that Dual boot is not a feature suitable for regular users. It is recommended to be installed only by developers who are comfortable with flashing devices and with their partition layout. Dual boot rewrites the Android recovery partition and those installing it should be intimately familiar with re-flashing it in case something goes wrong.

Multiple Android flavours are supported (AOSP or stock, CyanogenMod) and installation of Ubuntu can be done for all versions available in the phablet-flash channels.

Easy OS switch via apps

With dual boot, switching between OSs had never been easier. No more key combinations or command line interfaces to jump into the next OS: on each side, an app with a simple user interface will enable you to boot back and forth at the tap of a button.

New-Dual-Boot-Shots

 

The Android app manages the initial installation of Ubuntu, upgrades and rebooting into Ubuntu.

dualboot-ubuntu

 

On Ubuntu, the dual boot app provides an easy way to reboot into Android.

Installing dual boot

Installing and running dual boot can be done in a few easy steps. In a nutshell, it requires performing a one-off installation of the dual boot app in Android, which will enable you to both install the version of Ubuntu of your choice, and to reboot into Ubuntu.


Install dual boot on your device

Categories
technews

Honda Made the World’s First Smartphone Case With an Emergency Airbag

It looks like Honda has create a Smartphone Case with an emergency Airbag, Watch this cool video.

Categories
technews

CyanogenMod Installer Application Removed from Play Store

CyanogenMod Installer Application has been removed from the Google Play Store, after a Google advisory stating that the app is violation of Google developer terms and conditions.

Read the full blog post from cyanogenMod here

Categories
technews

Saving Gmail attachment Directly to your Google Drive

Google has rolled out a gmail update recently which allows you to save your gmail attachment directly to Google Drive. See the screenshots below.

There is a new Google drive icon popup in the attachment and once we click on that we get a list of Google Drives folders, select the folder and save, and done.

 

gmail-drive gmail-drive2