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What is Asynchronous Messaging Design Pattern?

What is Asynchronous Messaging Design Pattern?

What is Asynchronous Messaging Design Pattern?

Previously we saw about What is Microservice? and the principles followed while developing MSA and the available design patterns. also, we saw an API Gateway design pattern.

Today we will see what is Asynchronous Messaging Design Pattern is.

What is Asynchronous Messaging Design Pattern?

Previously we saw about Chained or Chain of responsibility design pattern which makes the client wait for a long time, It also breaks the chain if any one service goes down and cause a bad experience for the clients.

To avoid such bad experiences for the client, The Asynchronous design pattern can be used, which communicate with the available services using message queue or event driven approach and not sequentially.

Yes, Messaging or events, The Asynchronous design pattern uses the Messaging Queue (MQ) or Event driven like ActiveMQ, RabbitMQ, Kafka and other tools for its communication with other services.

Example:

Consider we have Cart, Product, Stock, Order & Shipping services.

When the Product is added to the Cart, Stock must be updated accordingly, So the Product calls stock via Message Queue.

And then Order calls shipment via Message Queue to prepare a label for shipment.

This way the client need not wait for the flow of service to be completed to get the response immediately.

what is Asynchronous design pattern?

 

In the next article, we will see Shared Database or Shared Data design pattern.

 

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WeCanCode-Author

WeCanCode-Author

November 11, 2021

Senior Developer | Java & C#.NET | 10++ years of IT experience.

Planning to learn ReactJS or Angular or Flutter.!

What is Chained or Chain of Responsibility Design Pattern

What is Chained or Chain of Responsibility Design Pattern

What is Chained or Chain of Responsibility Design Pattern

Previously we saw about What is Microservice? and the principles followed while developing MSA and the available design patterns. also, we saw an API Gateway design pattern.

Today we will see what is Chained or Chain of Responsibility Design Pattern is.

What is Chained or Chain of Responsibility Design Pattern?

The chained or Chain of responsibility pattern produces a single response which is a combination of multiple chained responses.

Example:

Consider we have Contact, Student & Fees three microservices, each web service communicates with the following or next service as in waterfall.

Yes, Contact service calls Student service and Student service calls Fees service. Response of Fees and Student will be returned back to Contact service.

What is Chained or Chain of Responsibility Design Pattern

Chained Or Chain Of Responsibility Design Pattern in Microservice

Here the Client must wait till the response comes back after the consolidated response is available, meaning the Client will be waiting for the chain of response to be returned back as a response.

Use this service where the client is not expecting any response. (Something like calling a batch job, synchronous tasks or orchestrated flow of actions.

All these services use the HTTP request or response for communicating,

Note: Each service request and response looks different from the chained flow.

 

In the next article, we will see Asynchronous Messaging design pattern.

 

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WeCanCode-Author

WeCanCode-Author

November 07, 2021

Senior Developer | Java & C#.NET | 10++ years of IT experience.

Planning to learn ReactJS or Angular or Flutter.!

Add Image to Android app

Add Image to Android app

Add PNG Icon to Android app

 

In this article, let discuss on

Add PNG Icon to Android app

Let us see how to Add PNG icon to Android App. In the end you your app will use the icon you have added for the android application.

 In this article I’m going to use the existing android project created as part of this article Make WordPress as Android App. This Follow the code repo used  ).

How to Add PNG Icon to Android App?

You can add Image assets by Right click on the location where the image or icon need to be placed.

See below screenshot for the Menu option in Android Studio.

  • After right-click drawable folder, Choose New > Image Assets
  • You need to choose the image or icon from the browse menu under Source Asset section of Foreground Layer Tab.
  • Adjust the Scaling according to the image or icon output.
  • Go to Background Layer tab and adjust the background color or image accordingly.
  • Once done, click Finish (Note: Try to keep the same name as the previous icon file name, if you are replacing the icon)
  • Run the App to see the new Icon changed.
intellij add image asset menu
WeCanCode-Author

WeCanCode-Author

October 22, 2021

Senior Developer | Java & C#.NET | 10++ years of IT experience.

Planning to learn ReactJS or Angular or Flutter.!

Searching a text in a file using grep

Here we’re going to searching a text in a file using grep?

Searching a text in a file using grep, this command will be very much handy when searching in multiple files or folders in unix terminal.

grep is one of the powerful command used for searching in files or folder with the search pattern.

Searching for text in file using grep

Lets see how to search for text or string in files or folders using grep command

Command Usage:
grep [options] "search pattern"[regex] [filename/foldername]
Note: use double quotes for your search string

Options : (Below are frequently used options with grep command)
-i Ignores case
-n Print the line number
-c Count of matched pattern (Will not print the search line, rather it just prints the count)
-r Will search folders for matching text.
-v non-matched lines are printed

Try for yourself:

1) Search for any string and print count
hint: use -c
2) Search entire folder for match pattern with , (This is special symbol)
hint: “\,”
3) Search string by ignoring the case and also search for multiple string in a file
hint: use -v and in search string you need to split using | for multiple search string.

Try for yourself and comment it here https://youtu.be/9pUPUEvJop8

practice to keep FAMILIAR with the commands.

Subscribe to our channel for more videos : https://bit.ly/aryanz-youtube

https://youtu.be/9pUPUEvJop8
Searching a text in a file using grep
~3Minutes: Tutorial

All about Permissions (CHOWN) in Unix – 3Minutes: Tutorial

Here we’re going to talk all about Permissions (CHOWN) in Unix?

When it comes to access for reading,writing or executing files in unix we need to play around with the permissions! So today we are going to talk all about ownership and permissions (chown).

Ownership and Permissions are important thing in unix, when it comes to files and folders access.

Changing ownership of files and folders using chown in unix - ~3Minutes:... youtu.be/Q3Mm4Lzeiyk via @YouTube #3MinTut #3MinutesTutorial #ShortTechTalk #LearningShort #unix #chown permissions and security #aryanz_co_in #balamtin #blog

Changing ownership for files and folders using CHOWN

Command Usage:
chown user:group filename (Changing ownership for user and group)
chown :group filename (Only to the group)
chown user filename (Only the user)
chown user:group foldername -R (For folders and sub directory use -R)
Note: -R to apply the changes to the sub directories and files within the folder.

owner – User who created the file or folder
group – User belong to the group
(groups example: admin, author, sysadmin, root, local, itadmin) – varies from system to system

Try for yourself:
1) Change both owner and group from root to user1 or user1 to root
hint: chown root:root file1.txt
2) Try to change for folder and its sub content (incl. sub directories)
chown root:aryanz_co_in folder1 -R

Try for yourself and comment it here https://youtu.be/Q3Mm4Lzeiyk

practice to keep FAMILIAR with the commands.

Subscribe to our channel for more videos : https://bit.ly/aryanz-youtube

https://youtu.be/Q3Mm4Lzeiyk
Changing ownership of files and folders using chown in unix - ~3Minutes:... youtu.be/Q3Mm4Lzeiyk via @YouTube #3MinTut #3MinutesTutorial #ShortTechTalk #LearningShort #unix #chown permissions and security #aryanz_co_in #balamtin #blog
~3Minutes: Tutorial

All about Permissions in Unix terminal

Here we’re going to talk all about Permissions in Unix terminal?

When it comes to reading, writing or executing files in unix we need to play around with the permissions! So today we are going to talk all about permissions in unix terminal (chmod).

Permissions are important thing in unix, when it comes to files and folders access.

How to change directory permissions in Linux

To change directory permissions in Linux, use the following:

chmod +rwx filename to add permissions.
chmod -rwx directoryname to remove permissions.
chmod +x filename to allow executable permissions.
chmod -wx filename to take out write and executable permissions.

Note that “r” is for read, “w” is for write, and “x” is for execute. 

This only changes the permissions for the owner of the file.

The 4 unix permissions categories (read, write and execute)

How to Change Permissions in Numeric Code in Linux – Watch it in below video

You may need to know how to change permissions in numeric code in Linux, so to do this you use numbers instead of “r”, “w”, or “x”.

  • 0 = No Permission
  • 1 = Execute
  • 2 = Write
  • 4 = Read

Basically, you add up the numbers depending on the level of permission you want to give.

example of changing permissions in numeric code in Linux

Permission numbers are:

  • 0 = —
  • 1 = –x
  • 2 = -w-
  • 3 = -wx
  • 4 = r-
  • 5 = r-x
  • 6 = rw-
  • 7 = rwx

For example:

chmod 777 foldername will give read, write, and execute permissions for everyone.

chmod 700 foldername will give read, write, and execute permissions for the user only.

chmod 327 foldername will give write and execute (3) permission for the user, w (2) for the group, and read, write, and execute for the users.

How to Change Directory Permissions in Linux for the Group Owners and Others

The command for changing directory permissions for group owners is similar, but add a “g” for group or “o” for users and “u” for owners:

chmod g+w filename
chmod g-rw filename
chmod o+w filename
chmod o-rwx foldername
example of how to change directory permissions in Linux for group owners and others

To change directory permissions for everyone, use “u” for owners, “g” for group, “o” for users, and “ugo” or “a” (for all).

  • chmod ugo+rwx foldername to give read, write, and execute to everyone.
  • chmod a=r foldername to give only read permission for everyone.

As you can see, there are several options when it comes to permissions. You have the capability to dictate usability among users. While it may be easier to just give all permission to everyone, it may end up biting you in the end. So choose wisely.

https://youtu.be/5n-a1NQXMus
All about Permissions in Unix terminal
~3Minutes: Tutorial

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