Scalability Fundamentals in System Architecture

Scalability Fundamentals in System Architecture

Architecture   March 23, 2026

🧱 What is Scalability (in Architecture)?

 

Scalability = the ability of a system to handle increasing load without breaking or slowing down significantly.

In simple terms:

If your users go from 1,000 → 1,000,000, your system should still work smoothly.”

 🎯 Why Scalability Matters

As an architect, your job is to ensure:

• System doesn’t crash under load
• Performance remains stable
• Costs stay controlled
  

 

🔑 SCALABILITY BASICS 

1️⃣ Types of Scaling

🔼 Vertical Scaling (Scale Up)

• Increase power of one machine (CPU, RAM)

Example:

• Upgrade server from 4GB → 32GB RAM

✅ Simple
❌ Has limits (can’t scale forever)

➡️ Horizontal Scaling (Scale Out)

• Add more servers

Example:

• 1 server → 10 servers behind a load balancer

✅ Highly scalable
✅ Used in modern systems

👉 Architects prefer this

2️⃣ Load Distribution

⚖️ Load Balancing

Distributes traffic across servers

Example:

• 10,000 users → spread across 5 servers

Benefits:

• Prevents overload
• Improves availability
  
  

3️⃣ Stateless vs Stateful Systems 

Stateless (Preferred)

• Each request is independent

Example:

• APIs where no session stored on server

✅ Easy to scale

Stateful

• Server stores session

❌ Hard to scale

👉 Solution:

• Use Redis / external session store
  

  
  

4️⃣ Database Scaling

📦 Read vs Write Problem

Read Scaling

• Use read replicas

Write Scaling

• Harder → use:
  • Sharding
  • Partitioning
     

5️⃣ Caching (MOST IMPORTANT)

Instead of hitting DB every time:

• Store frequent data in cache

Example:

• Homepage content
• User profiles

Tools:

• Redis

👉 Reduces load dramatically

6️⃣ Asynchronous Processing

Don’t do everything in real-time.

Example:

• Sending email after signup

Use:

• Queues

Benefits:

• Faster response
• Better scalability
  
  
  

7️⃣ Microservices (Advanced Scaling)

Break system into smaller services:

• User service
• Payment service
• Notification service

Each can scale independently

8️⃣ Fault Tolerance

System should not fail completely if one part breaks.

Example:

• If email service fails → app still works

Drupal Coding standard (Drupal and DrupalPractice) Setup

Drupal Coding standard (Drupal and DrupalPractice) Setup

phpcs   November 28, 2021

 Hello Drupalers,

Hope all are good and healthy.

Today we are going to discuss about how we can keep our code according the Drupal coding standard. While we write any code we keep logics according the functionality but its also important to write code according the standard.

Now Question is how we can check our code is according to standard or not. So in Drupal we usually check according the Drupal and DrupalPractice Coding Standard.

First we have to install and setup phpcs and phcbf in our local repo.

 composer create-project drupal/recommended-project drupal_contrib  
 composer require drupal/coder dealerdirect/phpcodesniffer-composer-installer  
 vendor/bin/phpcs --config-set installed_paths vendor/drupal/coder/coder_sniffer/  
 vendor/bin/phpcs -i  

 

we have to run all phpcs commands from vendor/bin/phpcs because we are setting up standards with local repo.

after setup Drupal and DrupalPractice standard install need to check the installed version.
To check installed version run 

The installed coding standards are PSR2, Squiz, PSR1, Zend, MySource, PEAR, PSR12, Drupal, DrupalPractice and VariableAnalysis

That's it if you find the Drupal and DrupalPractice in installed version you can use the to check your code accordingly.

Commands to check code according the Drupal Standard.

 vendor/bin/phpcs --standard=Drupal web/modules/contrib/<Module_name>  
 vendor/bin/phpcbf --standard=Drupal web/modules/contrib/<Module_name>  
 vendor/bin/phpcs --standard=DrupalPractice web/modules/contrib/<Module_name>  

Check deprecation and Make your project Drupal 9 compatible

Check deprecation and Make your project Drupal 9 compatible

drupal-check   March 20, 2020

Hello Drupalers,

As we know Drupal 9 will be release at 3rd of june 2020.

Drupal 9 = Drupal 8 - remove deprecation + increase dependency package

you are here because you also want to know ->

• How we can make our project Drupal 9 compatible ? 
• How we can check deprecated code ?

Drupal-check :- We can check all deprecated method using the "drupal-check".


Drupal check will provide you a result based on your project which deprecated method you used in your code and in the place of that code what should we should.


Install Drupal -check : - Download package using below command

 curl -O -L https://github.com/mglaman/drupal-check/releases/latest/download/drupal-check.phar  
 mv drupal-check.phar /usr/local/bin/drupal-check  
 chmod +x /usr/local/bin/drupal-check  

Composer :-
You can install this in your project using Composer as a development dependency like so:

 composer require mglaman/drupal-check --dev  

You can also install this globally using Composer like so:

 composer global require mglaman/drupal-check  

 Check Deprecation :- Now your system is ready to check any Drupal check with deprecation then you can make the project compatible with Drupal 9

If you installed drupal-check locally, open your terminal and run below command.

 lenovo@lenovo-ThinkPad-L450:/var/www/html/drupal_directory $ vendor/bin/drupal-checck web/modules/contrib/module_name  

If there is any error you will be able to see result like :-

  21   Call to deprecated function db_select():                  
      in drupal:8.0.0 and is removed from drupal:9.0.0. Instead, get       
      a database connection injected into your service from the container and   
      call select() on it. For example,                      
  ------ -------------------------------------------------------------------------  
  [ERROR] Found 1 errors  

Now you can remove deprecated code and make its Drupal 9 compatible.

How Drupal will know your project Drupal 9 compatible ?

Here is a way to let know Drupal.org that our module is Compatible with Drupal 8 and Drupal 9

 core_version_requirement: ^8 || ^9  

Add this line in your project info file. If want to know more about core_version_requirement see core_version_requirement



I hope guys you like this, if you have any suggestion and correcction feel free to comment here. Thanks 😊

How Drupal Core release version decides ?

How Drupal Core release version decides ?

Drupal8   March 19, 2020

Hello Drupalers,

There is one interesting thing about Drupal version.

Have you ever been thought how core contributor decided the Drupal release number ? 🤔


Today i am going to tell you how the core release version decide.

"Since Drupal 8.8.0 Core release follow the semantic versioning (semver) numbering system."

• Semantic versioning numbering uses three numbers instead of two  i.e (8.2.6)

In 8.2.6 first number is the major release number, second is minor number and third is patch number .

First Number (Major version) :- You are actually breaking API , there's no backwards compatibility with old API.

Second Number (Minor version) :- Minor version does not break compatibility with old version (Drupal 8.2 won't break compatibility of 8.1), This number is used for big changes or new feature.

Third Number (Patch Number) :- last number only shows bug fixes.

For more information please visit :-  Drupal Core release cycle

"Most Welcome any suggestion and correction in blog".

Thanks 🙂

Headless drupal 8 with vue js

Headless drupal 8 with vue js

headless drupal   March 19, 2020

Hello Drupalers,

Today i am going to show you how can create headless website with  Drupal 8 and vue.



We will step by step to create headless website.

Step 1 : -  Install a fresh Drupal 8.  In my case i  installed drupal with composer .

 composer create-project drupal-composer/drupal-project:8.x-dev decoupled_drupal --stability dev --no-interaction  

Step 2 : - In this case we will use rest api to get  drupal content data in our vue app using "REST Module."


Step 3 :-  Create custom content type as  i have created content type "Album" and added some fields











Step 4 :- create view for rest export data.

 make sure your api path (i.e api/edm-album)


Note : Now Drupal is ready for headless use now we will create vue frontent to get this api data and will dispaly on frontent.



Step 5  :- Inside of your Drupal folder install Vue-cli wo we can use

 lenovo@lenovo-ThinkPad-L450:/var/www/html/decoupled_drupal/drupalvue $ sudo npm install -g vue-cli  

Step 6 :-  Setup Vue instance for headless use

 vue init webpack <name_of_project folder>  
 # install dependencies and go!  
 cd <name_of_project folder>  
 //install node dependencies from package json  
 npm install  
 // run this command to start your project  
 npm run dev  

Last command is used for serve react application and after that you will be able to see some url like

http://localhost:8080/


make sure you are running above commands from your drupalvue directory.

Customization in drupal 8 core contact form using form alter

Customization in drupal 8 core contact form using form alter

Theme   November 17, 2018

How to change Drupal 8 Core Contact form fleld label :-

 If you want to change Contact form "Message" field label you can use "hook_form_alter" .

either you can create a custom module or either you can add form alter in your theme file also.

 

function your_theme_form_alter(&$form, \Drupal\Core\Form\FormStateInterface $form_state, $form_id) {
       if ($form_id == 'contact_message_feedback_form') {
        $form['message']['widget'][0]['value']['#title'] = t("My Custom Body Label");
     }
} 

Add placeholder in default search using form alter

function your_theme_form_alter(&$form, \Drupal\Core\Form\FormStateInterface $form_state, $form_id) {
    if (in_array($form_id, ['search_block_form', 'search_form'])) {
        $form['keys']['#attributes']['placeholder'] = t('Search...');
    }
   }if ($form_id == 'contact_message_feedback_form') {
  $form['actions']['submit']['#value'] = t("My Altered submit button text here");
  $form['subject']['widget'][0]['value']['#title'] = t ("My Altered title here");
  $form['message']['widget'][0]['value']['#title'] = t("My custom body text here");
        //$form['message']['widget'][0]['value']['#title'] = t("My Custom Body Label");
  $form['#suffix'] = "<div class='extra-text'><p>Show some text before the comment form.</p></div>";
     }

} 

Create Instances at AWS (Amezon Web services) and connect through SSH.

Create Instances at AWS (Amezon Web services) and connect through SSH.

Ubuntu   November 02, 2018

Step 1: Login your AWS Account.

Step 2: At the navigation click on services, and select "EC2".

Step 3 : If you want to create new site or application or Instance, you need to click on "launch Instances".

Step 4: There is a option for free and paid server for creating instances. ("Choose an Awazon Machine Image (AMI)")

Note : Amazon web services provide you 8 TB space if you want more than it you need to select paid server.

Step 5 : Go through all the steps, there is a option of create key pair, it will use to connect your AWS website with ssh, but remember on thing you can create a pair key only one time and if another user want to access this folder you have to share your pair key.

eg. test.pem file



Step 6 : Connect instances using ssh and pem file

download your pem file and put this at your desktop and connect through ssh username and password.

Step 7 : you need to give the permission of your pem file to read and write.

$ chmod 400 test.pem


Step 8 : SSH Command :

ssh -i YOUR_PEMFILE.pem user@publicdns/domainname

ex - ssh -i xyz.pem ec2-user@ec2-45-415-458.compute-1.amazonaws.com

 
Step 9 : Now you will connect to your AWS Account :)

Step 10 : At AWS account click on your instances, below you will find description tab under that public DNS(IPv4)  ec2-45-415-458.compute-1.amazonaws.com, click on that link you will redirect your web page of your instances.

How to Change 'Any' option in exposed filter in Drupal 8.

How to Change 'Any' option in exposed filter in Drupal 8.

Drupal8   October 29, 2018

If you Want to Change label of "Any" in exposed filter option in Drupal 8. You can use "Better exposed filter" . here thesome step to change of Any text in D8.

Step 1 : Open your Better exposed filter setting and find out the filter in which you want to change the label.

Step 2: Scroll down at the bottom select  "More options for "field_ad_category_target_id(your filter name)".


Step 3 : Click on "Rewrite filter options"


Step 4 : put this in "Retrite the text option"

 example : - Any -| Your option

Step 5: in my case i want to change "Any" label to 'Your option'. i hope this will work for you :)

My trick to add Colorbox popup on Slideshow images in Drupal 8

My trick to add Colorbox popup on Slideshow images in Drupal 8

Drupal8   October 24, 2018

Hello, If you want to show any slider image in the popup form on click on image
here is the my funny or easy trick to do it. i hope it will work for you :)

Trick 1 :-  I have a task that i have created a slider using image fieldslideshow , i have done this by using view and just set image formatter as image fieldslideshow but now requirement is that when we click on the image it should be open as colorbox popup.


solution : -
   step 1 :- I have added a same image field in view and set formatter "colorbox" and excluded that filed, its all because shwo we can found colorbox library on required page.

step 2 :-  just change twig file structure according colorbox :-

From :-

{% for key,value in url %}
            <img src="{{ value }}" />
        {% endfor %}


To :-

{% for key,value in url %}
    <a href="{{ value }}" class="colorbox cboxElement"><img src="{{ value }}" /></a>
    {% endfor %}

Step 3 :- Now you will be able to see popup on your slider image

 

Trick 2 - Need to add popup on field slide show image.

Step 1:- i have set filed slideshow on display format of image and link image to file.

Step 2:- create a other image field to and set Colorbox format to call Colorbox library, set a default image in this field, disable from disaplay form, and just add Css for display none.

Step 3 :- there is same structure which we want for colorbox popup except colorbox class so i have  added class using jquery

jQuery('.field--name-field-product-image .field-slideshow').find('a').addClass('colorbox cboxElement');

 

How to Show all products and node related to the node user

How to Show all products and node related to the node user

Drupal8   October 24, 2018

When we click on the node or product and you want to show show all the products related to the user who publish the current user. you have to apply filter user id filter i am showing you in the below post.


Step 1 : - Firstly you have to change the "url alias" for the node and need to add author name.

eg. if you have product content type your path pattern should be like              
 ( [node:title]/[node:author] ) this.

path pattern:- [node:title]/[node:author]

Step 2 :- You Need to add "user Name" contextual filter in the view block.
if your url link this ->  
http://115.166.142.238/souq_alhrag/ar/samsung-galaxy-j2-core/customer

http://<ip>/<projectname>/<language>/<nodeid>/<username>

select raw value under "Provide default value"and path alias 2 in my case.

Exclude current Node in Block view in Drupal 8

Exclude current Node in Block view in Drupal 8

Drupal8   October 24, 2018

If you want to exclude current node and product in block view in drupal 8 pls follow the below steps.


Step 1 :-  Create a block view.

Step 2 :-  Add Content Under "Contextual Filters", select "Provide Default value"->"Content Id from url"

Step 3 :- Scroll Down at bottom and Check "Exclude" under "More".

 

 

Step 4 :- Apply filter and save changes , now only content id which is the url doesn't show in the block view.

How to Add Popup using jQuery

How to Add Popup using jQuery

jQuery   October 23, 2018

Add popup on any div using jQuery :-

HTML : -

<div class="disclaimer custom-popup">
    <div class="container">
        <div class="close">X</div>
        Lorem Ipsum is simply dummy text.
        </div>
    </div>
<div class="disclaimer-show">Disclaimer</div>

JQuery : -

jQuery(document).ready(function(){
    /*Disclaimer popup*/
jQuery('.disclaimer').hide();
jQuery(".disclaimer-show").bind('click', function () {
    jQuery(".disclaimer").show();
    jQuery(this).hide();
})

jQuery('.close').bind('click', function () {
    jQuery('.disclaimer').hide();
    jQuery('.disclaimer-show').show();
})

});

CSS : -

.custom-popup {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(255,255,255,0.85);
    z-index: 9999;
    overflow: auto;
    padding: 25px;
}
.custom-popup .container {
background-color: #fff;
    max-width: 1170px;
    margin: 50px auto;
    border: 1px solid #0098DB;
    padding: 30px 50px;
    position: relative;
}

.custom-popup .close {
    width: 32px;
    height: 32px;
    background-color: #0098DB;
    text-align: center;
    color: #fff;
    font-size: 22px;
    position: absolute;
    right: -15px;
    top: -15px;
    line-height: 32px;
} 

 

Add Node as a popup in Drupal 7

Add Node as a popup in Drupal 7

Drupal7   October 23, 2018

How to Show Any Node in the popup form in Drupal 7 :-

If you want to Show any node or page in the poup form when click on the link add the link in this format in your block.

 <div><a class="colorbox-node colorbox-node-gallery" href="/disclaimer?width=600&height=600" rel="gallery">My Popup Example</a></div>  

How To Translate Read more text in Drupal 7

How To Translate Read more text in Drupal 7

Drupal7   October 22, 2018

Translate Read More link in drupal 7 : -

under config->translate interface click on translate tab, then select "Read More" string in string search.

 click on edit and then put your required string in required language.

 path : yourdomainname/admin/config/regional/translate/translate  

Import and Export Database using ssh

Import and Export Database using ssh

Ubuntu   October 21, 2018

Import Database using ssh :- 

 mysql -u <database_username> -p -D <Your_databasename> < <database_path>  
 Example :-   
  mysql -u abcpanam_devuser -p -D abcpanam_abcpanama < abcdistr_abcpanama(1).sql 

Export Database using ssh :- 

 [abcdistr@server ~]$ mysqldump -u abcdistr_ntf -p abcdistr_abcpanama > abcdistr_abcpanama.sql 

IMPORT AND EXPORT DATABASE AT lOCALHOST USING TERMINAL

Connect Terminal to database

 $ mysql -h 127.0.0.1 -u root  
 $ /opt/lampp/bin/mysql -uroot -ppassword  
 ntf-22@NTF-22:/$ /opt/lampp/bin/mysql -uroot (IF THERE IS NO PASSWORD) 

IMPORT :-

ntf-22@NTF-22:~$ sudo /opt/lampp/bin/mysql>mysql -u root ssh_test_db < /home/ntf-22/Desktop/abcdistr_abcgrouptt.sql  
ntf-22@NTF-22:~$ sudo /opt/lampp/bin/mysql>mysql -u <database_username> <database_name> < <downloaded_database_sql_file_path_at_your_system>  

EXPORT:-

ntf-22@NTF-22:~$ /opt/lampp/bin/mysql>mysqldump -u root -p ABC_magento_db > ABC_magento_db.sql  
 ntf-22@NTF-22:~$ /opt/lampp/bin/mysql>mysqldump -u <database_username> -p <database_name> > <new_database_name.sql> 

Basics Ubuntu Terminal commands

Basics Ubuntu Terminal commands

Ubuntu   October 21, 2018

Some basics command to use terminal in Ubuntu Linux

S. NO	COMMAND	EXAMPLE	BRIEF DESCRIPTION
1.	cd <folder_name>	ntf-22@NTF-22:~$ cd /home/ntf-22/	To enter in a folder
2	cd  ..	ntf-22@NTF-22:~$ cd ..	exit from a folder
3	cd  /..	ntf-22@NTF-22:~$ cd /..	Exit from all folder and move at root
4	pkill  <software_name>	ntf-22@NTF-22:/$ pkill geany	Used to close specific software.
5	<software name>	ntf-22@NTF-22:/$ geany	Open directly through terminal
6	ssh username@domain	ntf-22@NTF-22:~$ ssh ntf-15@192.168.1.101	Connect other system using terminal
7	sudo mv frompath topath	ntf-22@NTF-22:/$ sudo mv opt/lampp/htdocs/swati-drupal home/ntf-22/Downloads	Move folder from terminal
8	sudo frompath/foldername  topath/folderRename	ntf-22@NTF-22:/$ sudo mv opt/lampp/htdocs/swati-drupal home/ntf-22/Downloads/swati-move	Move and Rename  folder using terminal
9	grep sshd /var/log/auth.log	ntf-22@NTF-22:~$ grep sshd /var/log/auth.log	Know whoes access your system and when .
10	gksu gedit /etc/hosts	ntf-22@NTF-22:~$ gksu gedit /etc/hosts	Search your website which you want to unblock and delete, if you want to block add url of the site.
11	mkdir <filename>	ntf-15@NTF-15:~/Music$ mkdir tt	Creating folder using command
11	rmdir <filename>	ntf-15@NTF-15:~/Music$ rmdir tt	Remove Folder Using command.
12	pwd	ntf-15@NTF-15:~$ pwd	Print Current Working Directory Show in which directory are you working.
13	ls	ntf-15@NTF-15:~$ ls	Print List of Directory
14	history -c	ntf-22@NTF-22:/$ history -c	Clear history of open terminal.
15	cp -R source destination	ntf-22@NTF-22:~/Downloads$ cp -R /home/ntf-22/Downloads/testing /home/ntf-22/Desktop/	Copy and paste from terminal you can also copy and paste your file
16	zip -r folder.zip folder	ntf-22@NTF-22:~/Downloads$ zip -r testing.zip /home/ntf-22/Downloads/testing	Create zip file using terminal
17	pathwhereyouwanttoxtract$ unzip folder.zip	ntf-22@NTF-22:~/Downloads$ unzip drupal8.zip	Extract folder using terminal
18	$ passwd	ntf-22@NTF-22:~$ passwd	Change password for system
19	$ scp source_path  user@domain:/destinationpath	ntf-22@NTF-22:~$ scp /home/ntf-22/Downloads/test.php ntf-15@192.168.1.101:/home/ntf-15/Desktop	Put file in other system
20	$ scp user@domain:/path yourpath	ntf-22@NTF-22:~$ scp ntf-15@192.168.1.101:/home/ntf-15/Desktop/t.png /home/ntf-22/Desktop/	Get from other system
21	php -m	ntf-22@NTF-22:~$ php -m	it shows the list of enable module in php
22	php -m | grep <name of extention>	ntf-15@NTF-15:/$ php -m | grep ctype	Checking extension enable or not in your php server
23	sudo apt-get install php7.0- <name of extention>	ntf-15@NTF-15:/$ sudo apt-get install php7.0-dom	To install php extension in server

How to Connect ssh in ubuntu linux.

How to Connect ssh in ubuntu linux.

Ubuntu   October 21, 2018

 

Connect Cpanel using ssh in Ubuntu linux :-

 

1. Create ssh key 
2. Authorize key
3. Download id_rsa.pub file
4.  Put this file at your system where ever you want. In my case i always prefer Desktop
5. Open your Terminal 
6. Open Folder where have you put id_rsa.pub file like

     ntf-22@NTF-22:/$ cd home/ntf-22/Desktop/ 

  
   7) Now You will see like this            

     ntf-22@NTF-22:~/Desktop$   

  
  8) Here you have entered in Desktop folder

    9) connect ssh using pub file

    ntf-22@NTF-22:~/Desktop$ ssh -i id_rsa abcdistr@abcdistributionusa.com  

10) Connect SSH when specific port is define  

   ssh -p 2222 abcpanam@162.241.224.18  
   ntf-22@NTF-22:~$ ssh -i id_rsa.pub -p 2222 abcpanam@abcpanamainc.com 

 

 The main ssh Connect command is (ssh -i <name_of_pub _file> username@domain)  

  In my case pub fille

  name is = id_rsa

  Username = abcdistr

  Domain = abcdistributionusa.com

 

 eg.
 10) Enter Cpanel password

   abcdistr@abcdistributionusa.com's password:  

 
  11) you will see like this   

   Last login: Fri Dec 15 09:39:53 2017 from 115.166.142.238  
   [abcdistr@server ~]$  

  

  12) You have successfully access using ssh but if you get ssh enable error then consult with  help and support they will enable ssh for your account. :)

How to add missing node id in Drupal 8

How to add missing node id in Drupal 8

Theme   October 20, 2018

Add Missing Node id in drupal 8 :- 

By default node id will not be there in the drupal 8. to enable this you have to add this code in your .theme file ->

   function THEMENAME_preprocess_html(&$variables) {  
    // Add node id to the body class.  
    $node = \Drupal::routeMatch()->getParameter('node');  
    if($node) {  
     $variables['attributes']['class'][] = 'node-' . $node->id();  
    }  
   }  

Most important module list in Drupal 7

Most important module list in Drupal 7

Drupal7   October 20, 2018

Sr.  no.	Module name	Installation url	Brief Description
1	Administration menu	https://www.drupal.org/project/admin_menu	Used for drop down admin menu.
2	Front page	https://www.drupal.org/project/front	Used for different front page for anonymous and authentic user.
3	Backup and Migrate	https://www.drupal.org/project/backup_migrate	To take backup from site.
4	Ckeditor	https://www.drupal.org/project/ckeditor	For best html editor.
5	Flexslider	https://www.drupal.org/project/flexslider	Used for image slider.
6	Panel	https://www.drupal.org/project/panels	Create page layout for content type with block field and views.
7	Module filter	https://www.drupal.org/project/module_filter	Filter module from module name if you have lots of modules.
8	Newsletter	https://www.drupal.org/project/newsletter	For subscribe website it show a subscribe link with the form.
9	Pathauto	https://www.drupal.org/project/pathauto	Automatic provide path for content type and user and for all nodes.
10	poll	https://www.drupal.org/project/poll	Create online voting in drupal 7.
11	Views	https://www.drupal.org/project/views	Most important and backbone of Drupal.
12	Php filter	Core module	Enable to add php code field in text format of the block.
13	Entity reference	https://www.drupal.org/project/entityreference	Create taxonomy reference and relationship with view.
14	Webform	https://www.drupal.org/project/webform	To create contact form.
15	File (field) path	https://www.drupal.org/project/filefield_paths	Specify the diiferent storing path of image and other file for different content type and also create a diiferent folder for storing purpose.
16	String Override	https://www.drupal.org/project/stringoverrides	Replace the by default message text.
17	Calendar	https://www.drupal.org/project/calendar	To create calendar and filter date wise content with view.
18	Owl carousel	https://www.drupal.org/project/owlcarousel	Nice slider with fields like title body author name.
19	Colorbox	https://www.drupal.org/project/colorbox
20	Menu Attribute	https://www.drupal.org/project/menu_attributes	Add class ,id, style, attribute to menu.
21	Modal form	https://www.drupal.org/project/modal_forms	Used for show all form in a popup.
22	Commerce wishlist	https://www.drupal.org/project/commerce_wishlist	Used to create fav. List or wishlist in drupal commerce.
23	Css injector	https://www.drupal.org/project/css_injector	To add css property from website or from admin dashboard.
24	Scroll to top	https://www.drupal.org/project/scroll_to_top	It added back to top arrow and scroll smoothly the page at top.
25	Sticky Navigation	https://www.drupal.org/project/stickynav	Used to create sticky menu.
26	Block Class	https://ftp.drupal.org/files/projects/block_class-7.x-2.3.zip	Used to add class to specific block.
27	Floating block	https://www.drupal.org/project/floating_block	To Create sticky block and you can also use both id and css for this.
28	Block Attribute	https://www.drupal.org/project/block_attributes	Used to add attribute in block like style, id, css.
29	Drupal Chat	https://www.drupal.org/project/drupalchat	Purpose of module chatting with other user.
30	Animate Any	https://www.drupal.org/project/animate_any	Animate any content of of page on page load.
31	Organic Group	https://www.drupal.org/project/og	Enable users to create and manage their own 'groups'.
32	Block Class	https://www.drupal.org/project/block_class	Block Class allows users to add classes to any block through the block's configuration interface
33	Responsive Menu	https://www.drupal.org/project/responsive_menus	Responsify your menus! Just give me a CSS/jQuery style selector of your menu and I will make it mobile friendly
34	Superfish Menu	https://www.drupal.org/project/superfish	Superfish integrates jQuery Superfish plugin with your Drupal menus.
35	TB Mega Menu	https://www.drupal.org/project/tb_megamenu	TB Mega Menu allows you to create a mega menu with an innovative back-end user interface and synchronized with Drupal core menu.
36	Quick Tab	https://www.drupal.org/project/quicktabs	The Quick Tabs module allows you to create blocks of tabbed content, specifically views, blocks, nodes* and other quicktabs*. You can create a block on your site containing multiple tabs with corresponding content.
37	Field Permission	https://www.drupal.org/project/field_permissions	The Field Permissions module allows site administrators to set field-level permissions to edit, view and create fields on any entity.
38	Panel Extra LAyout	https://www.drupal.org/project/panels_extra_layouts	Panels is one of the most, if not the most, powerful modules for laying out a page in Drupal.
40	Menu Per Role	https://www.drupal.org/project/menu_per_role	This module allows you to restrict access to menu items based on user roles. Just activate the module and edit a menu item as usual. There will be a new fieldset that allows you to restrict access by role.
41	Twilio (Send Message To Phone)	https://www.drupal.org/project/twilio	The Twilio module provides integration with the Twilio cloud communication platform allowing for your Drupal site to integration Voice and SMS functionality.
42	Better Exposed filter	https://www.drupal.org/project/better_exposed_filters	the Better Exposed Filters module replaces the Views' default single- or multi-select boxes with radio buttons or checkboxes, respectively. Description fields and Select All/None links can be added to exposed filters to make for a better user experience.
43	Read More	https://www.drupal.org/project/readmore	Add read more link on body and show without refresh page.
44	Context module	https://www.drupal.org/project/context	Used for creating differnt layout for different content type and node it work as a panel module.
45	context by node	https://www.drupal.org/project/context_by_node	Context by node allows you to create a context for each node. The context created will apply just for that node.
46	context node	https://www.drupal.org/project/context_node	Context Node allows you to select a predefined context when creating a node.
47	Word count	https://www.drupal.org/project/wordcount	Count words according to creatore user /Used to see particular user creates node. Check in the report->word count
48	Read time	https://www.drupal.org/project/read_time	Display the recuired to read specific node.
49	Node view count	https://www.drupal.org/project/nodeviewcount	Display the total view of particular node and dispaly using default node.
50	Hierarchical Select	https://www.drupal.org/project/hierarchical_select	Display sub term of texonomy in hierarical.
51	Taxonomy menu	https://www.drupal.org/project/taxonomy_menu	Added sub term as sub menu of main menu
52	Feeds Module	https://www.drupal.org/project/feeds	Added multiple notes at a single import click using csv.
53	PDF using MPDF	https://www.drupal.org/project/pdf_using_mpdf	Used to generate pdf from html
54	Boost module	https://www.drupal.org/project/boost	Used to increase site performance.
55	File Entity	https://www.drupal.org/project/file_entity	Used to show file tab in admin section
56	Adminstration View	https://www.drupal.org/project/admin_views	Used to Show filters in administration section
57	Rabbit Hole	https://www.drupal.org/project/rabbit_hole	Used to Access denied on node but can display in the other format like view block , page , slider for annonumous user
58	Bean Module	https://www.drupal.org/project/bean	Used to add fields in cutom block in drupal 7