The upgrade must be done in incremental through major versions:-

• 5.1
• 5.5
• 5.6 and finally to
• 5.7

This ensures that the actual database table schema definition changes are properly handled by the mysql_upgrade function of mysql.

The service runs as mysql until mysql 5.6 but it’s mysqld from 5.7 onwards. We will download and install the binaries straight from mysql site i.e we will not rely on any EPEL or IUS repository. You will need sudo access to perform the upgrade.

Backup your database for safety.
Download your favourite zipper.
yum install xz
mysqldump –routines –all-databases | xz > /root/mysqlupgrade/mysql51/mysql-5.1.dump.sql.xz

Step 1: upgrade from 5.1 to 5.5

Download rpms or get the download link from https://dev.mysql.com/downloads/mysql/5.5.html#downloads to upgrade to 5.5 first. A .tar will have all the dependencies of that version.

Upload using FTP software (eg filezilla) the downloaded rpm or ssh into your server and do the wget of rpm tar to any location that has write permission. 

Shutdown MySQL 5.1 for upgrade

mysql -u root -ppassword --execute="set global innodb_fast_shutdown=0"
or simply run:
set global innodb_fast_shutdown=0
logging into mysql.
mysqladmin -u root -ppassword shutdown

Go to the directory where you have write permission and get the .tar of rpms
wget https://cdn.mysql.com//Downloads/MySQL-5.5/MySQL-5.5.62-1.el6.x86_64.rpm-bundle.tar

Extract it,
tar -xvf MySQL-5.5.62-1.el6.x86_64.rpm-bundle.tar 

Uninstall the old 5.1 rpms. Get the list by:-
rpm -qa | grep ‘MySQL’

Uninstall the output  each one by using rpm -e:-
rpm -e MySQL51-client-5.1.73-1.cp1150.x86_64 MySQL51-shared-5.1.73-1.cp1150.x86_64 MySQL51-server-5.1.73-1.cp1150.x86_64 MySQL51-test-5.1.73-1.cp1150.x86_64 MySQL-embedded-5.5.62-1.el6.x86_64 MySQL51-devel-5.1.73-1.cp1150.x86_64

Go to the extracted directory and install the ones of 5.5 extracted recentely by tar:-
rpm -ivh MySQL-server-5.5.62-1.el6.x86_64.rpm MySQL-shared-5.5.62-1.el6.x86_64.rpm MySQL-test-5.5.62-1.el6.x86_64.rpm MySQL-client-5.5.62-1.el6.x86_64.rpm MySQL-devel-5.5.62-1.el6.x86_64.rpm MySQL-embedded-5.5.62-1.el6.x86_64.rpm

Check the mysql version:-
mysql --version

It should be upgraded to 5.5.62.

Remove or Rename the my.cnf. Not all options are compatible for 5.5, you will have to pick the required ones later:-
mv /etc/my.cnf /etc/my.5.1.cnf

Now the most important step and reason for the incremental updates. Let mysql fix the schemas of it for new version by running:-
service mysql start
mysql_upgrade

If you not running as root or have set root password for mysql, you will need to specify the user while doing upgrade
mysql_upgrade -u root -p

It should start fixing the upgrades of all your tables and says ok at the end. Restart the mysql server with:-
service mysql restart 

The mysql is now updated to 5.5

Congratulations. 

Step 2: Upgrade from MySQL 5.5 to 5.6

Just follow the exact steps of Step 1 except the rpms you should be erasing will be of 5.5 and installing new will be of 5.6. So make sure you are downloading 5.6 rpms.

rpm -e MySQL-shared-5.5.62-1.el6.x86_64 MySQL-test-5.5.62-1.el6.x86_64 MySQL-server-5.5.62-1.el6.x86_64 MySQL-devel-5.5.62-1.el6.x86_64 MySQL-embedded-5.5.62-1.el6.x86_64 MySQL-client-5.5.62-1.el6.x86_64

Download the 5.6 tar binaries, extract it and go to that folder.

rpm -ivh MySQL-client-5.6.44-1.el6.x86_64.rpm MySQL-devel-5.6.44-1.el6.x86_64.rpm MySQL-embedded-5.6.44-1.el6.x86_64.rpm MySQL-server-5.6.44-1.el6.x86_64.rpm MySQL-shared-5.6.44-1.el6.x86_64.rpm MySQL-test-5.6.44-1.el6.x86_64.rpm

Step 3: Upgrade from MySQL 5.6 to 5.7

Just follow the exact steps of Step 1 except the rpms you should be erasing will be of 5.6 and installing new will be of 5.7. So make sure you are downloading 5.7 rpms from mysql official site.

Note:

Make sure to kill the mysql process by if any error related to lock.

Find PID by:-
pidof mysql
Kill -9 PID

1. We need to have at least some blockers for brute-force attacks. This is the type the intruders consistently try logging in with all possible combination of username/password unless its successful. This type of attempts can be detected very easily. For this type of attempts and other advanced security features we can install some free wordpress plugins, like, Wordfence security plugin (https://wordpress.org/plugins/wordfence/).
2. Timely updation of the core wordpress version and plugin is required. Technology is evolving and intruders always tend to overcome with existing security measures. So it should be tightened more. Updating core of websites and plugins is one and only way the original developer can help us to secure the software they have provided to us. Outdated plugins which have not been updated in at least last 1.5 year should be removed and getting appropriate alternative is recommended. There might be having some security loop-hole left unmaintained. Carefully choose the plugins and themes before installing into the site.
3. Adding Captcha or 2 factor authentication in WordPress admin login is best way that only valid users enter into the admin area. Using captcha in open word forms like contact us also helps to prevent bot submissions and annoying notifications.
4. Changing administrative passwords of users and passwords of servers/cPanel should  be performed regularly. Periodic checking of valid admin users & Unwanted administrators access should also be removed. This prevents unwanted control of the site if somehow the site credentials got leaked, eg: via mobile phone or phishing.
5. Regular scanning of the open ports of the site should be performed in case if any unwanted service is left open accidentally by developer or hosting provider. It can be done using some open source tools or with many online sites. The most popular software is nmap. Following table is an example scan result of a domain to find out the open ports using nmap:Command used
   nmap -sS -O -p 1-65535 -T4 yourdomain.com –vvvOutput:
   Open port : 21             ftp
   Open port : 25             smtp
   Open port : 53             domain ISC BIND
   Open port : 80             http nginx
   Open port : 110           pop3 Dovecot pop3d
   Open port : 143           imap
   Open port : 443           https
   Open port : 465           smtp
   Open port : 587           smtp
   Open port : 993/tcp     imap Dovecot imapd
   Open port : 995/tcp     pop3 Dovecot pop3d
   Open port : 2082/tcp
   Open port : 2083/tcp
   Open port : 2095/tcp
   Open port : 2525/tcp
   Open port : 2096/tcp
   Open port : 18765/tcp   The above open ports are for standard services and doesn’t look to be vulnerable but the problem here is anyone can easily scan over them. Ports are for services and if in any case, if sensitive ports are left open, they are vulnerable and become target to automated port scanning malware script that are always running to seek out someone’s mistake. A secure server or hosting provider should block such port scanning. This can also be considered as a measure of how seriously a hosting provider take security issues.
6. Scanned the website with common popular online vulnerability scanner sites especially to check if there are any cross site scripting, ssl signature issues, loopholes or thing like that if there in the site to the public. No information should be shared in such sites though, they should  just be given url and ask to check if they can find any holes in the site/server/ssl. This should be done especially after any updates are made to the site by the developer or by plugin/theme/core engine update.
   Some popular examples at the time of writing:
   https://scanmyserver.com,
   https://www.ssllabs.com,
   https://app.webinspector.com/,
   https://pentest-tools.com/website-vulnerability-scanning/xss-scanner-online
   https://sitecheck.sucuri.net.
7. Choose hosting plan that give complete ftp/ssh and access logs. This will be helpful to track down the intruders and find the cause of it. Mostly dedicated servers like aws ec2 instance give this access. Shared hosting rarely have this option to shared hosting accounts. Make sure the hosting has firewall and software to deal with most common attacks like ddos.
8. Make sure the hosting regularly scan the scan the site files and databases and the anti malware scanners are updated with the most common type of vulnerability detection pattern or database.
9. All the sql dumps and zipped files as backup of the site should not reside in web root (inside pubic_html) or in inner folder of it unless they are protected by external access through apache module rules like .htaccess. Anyone can download those databases/files easily through website url via normal scanning since they are publicly accessible. The intruders not only get your sensitive data from database dumps and private files but also know the internals of the system and find out the weak areas for later intrusion attempts to production data.
10. Get automated backup of whole files and database in at least every 15 days interval so that if any section of the database or file gets infected, these can be replaced.
11. Always have SSL (https) installed in your site, especially if it involves user data pass through the network. This prevents header tempering and Eavesdropping attack.
12. It is always a best practice to put your website behind a reverse proxy for availability and security (hiding the actual ip address).

• Unable to print the text in console (linux terminal /windows command line). They are unreadable.
• Reading/writing text in database

Printing Nepali text in Console/Terminal
While doing development or running some machine learning libraries, we frequently need to print out the text in terminal. For nepali text, getting them printed out in terminal is challenging. But there are solutions to it.

There are many different solutions to print unicode characters to display in format of UTF-16 and UTF-8 for languages like C or C++.
 In C++,
_setmode(_fileno(stdout), _O_U16TEXT);

This settings works but not to all languages like Nepali, Arabic or Hebrew. It was not helpful since it did not correctly display all Nepali text. Furthermore, my work was also requiring to print out Nepali text from python language interpreter into the terminal. For it, in linux terminal, I tried to setup all languages and locals and managed to display Nepali text but it also had limitations of displaying all characters correctly. Not all words were corrected displayed and looked like I was still lacking the actual fonts (tried more than 10 that should have supported devanagari font). 

So instead of wasting my time in trying with every available fonts and settings, I decided to to with an awesome new terminal called Konsole. You can download it from here, https://konsole.kde.org/. I was able to install it so easily with a single line command and get it running into my Ubuntu 18 machine straight away. 

sudo apt-get install konsole

It was of the version 4:17.12.3 at the time of my experimentation. After the installation, Just run it from GUI and we will be presented with terminal similar to linux inbuilt terminal (For linux variations having GUI). All nepali texts were correctly displayed and another interesting feature of it was it has all the features and functionalities that a normal terminal has. So you can run any command with it and play along with any unicode non-latin texts.

Reading-Writing Nepali text in Database
Another challenge in NLP work for Nepali text is properly storing and fetching data in/out from database. I mostly worked with MySQL/Mariadb for it so typical example will be for this database but the concept will be equally applicable to other data storage technologies. 

Storage
The first and most important setup to do is to make sure the mysql character set and collation is set to utf8. Personally I prefer utf8_general_ci. This is how we can do it after logging into mysql terminal or from phpmyadmin SQL Query input. There are various ways to do it like via my.cnf of db config file etc but the simplest way is to run straight query to the engine for the particular database or table.

ALTER DATABASE dbname CHARACTER SET utf8 COLLATE utf8_general_ci;

This will change the character set and collation of your whole database. Do not forget to replace the dbname by your actual database name. 

To do this only for particular table:

ALTER TABLE tablename CHARACTER SET utf8 COLLATE utf8_general_ci;

Reading/Writing from popular programming language

Python
Python handles nicely the encodings without any extra parameters while reading from mysql database. Install mysql connector through pip and import it. 

pip install mysql-connector-python

You can choose the specific version if you like

pip install mysql-connector-python==8.0.11

import mysql
import mysql.connector
mydb = mysql.connector.connect(
 host="localhost",
 user="manoj",
 passwd="pass",
 database="db"
)

mycursor = mydb.cursor()
mycursor.execute("SELECT fields FROM table")
result = mycursor.fetchall()

And do the straight query as above (not focused here on best practices and structured way)

For writing, straight execute function will again work as long you have maintained the character encoding and collation. 

Java
For connecting mysql with java application, I used mysql.jdbc.Driver. The jar file after downloading from mysql official site was added into the CLASSPATH so that Java Virtual Machine or the Java compiler know the location of this package.

export CLASSPATH=:/home/manoj/commons-lang3-3.9.jar:.:/usr/share/java/mysql-connector-java.jar:.:/home/manoj/commons-text-1.6.jar

Note: Had to use commons-lang and commons-text packages as well for text processing.

I think had to explicitly define the characterEncoding while connecting to db. Since I was in local and no SSL was setup for local connection, set the useSSL to False. 

String myDriver = "com.mysql.jdbc.Driver";
String myUrl = "jdbc:mysql://localhost:3306/lda?characterEncoding=UTF-8&useSSL=false";
try {
        Class.forName(myDriver);
} catch (Exception ex) {
        System.out.println("could not connect to mysql. exiting.");
}

Connection conn = DriverManager.getConnection(myUrl, "root", "manoj");

Make sure your mysql is running on 3306 port and db username/password and db name matches to yours.

I was able to get the Nepali text by simple fetch query

String query = "SELECT * FROM table";
// create the java statement
Statement st = conn.createStatement();
ResultSet rs = st.executeQuery(query);

For inserting the data, I was able to do it once the connection was made with defined characterEncoding.

query = "INSERT INTO ……..";
st.addBatch(query);
st.executeBatch();

PHP
The character set of mysql had to be set to utf8 to read and write in PHP.

// Create connection
$conn = new mysqli(‘localhost’, ‘manoj’, ‘db’, ‘db’);
// Check connection
if ($conn->connect_error) {
   die("Connection failed: " . $conn->connect_error);
}

//set character set
mysqli_query($conn, "set names 'utf8'");
$sql = "SELECT * from table";
$result = mysqli_query($conn, $sql);

The same connection object $conn was able to insert data without any further processing specific to character encoding. 

Note: All of the above examples assume you have already set the character and collate to utf-8 in your mysql database.

• Main file in index.js which loads the main component
• Each component then loads the corresponding sub component. Component loading is done by including the jsx file
• Jsx file notation is like html notation. Each jsx file has render() method and state() property.
• When loading a component, it calls the render() method internally
• Variables are put within {  } notation.
• It’s not a template engine. So all logic should be written in pure JS notation.
• Components are reusable.
• Normally main component starts at index.js. This includes the main App which then can include the child components. Each child component then include sub child components are so on. So any section of a page of project that we want to make reactive or to use react, its rending starts from index.js.
• Multiple subcomponent of a component if needed to include, we can use 

<React.Fragment>

</React.Fragment>

• To include a component, need to import the jsx file and the classname of it like:

           import ComponentName from “PATH_TO_COMPONENTJSX_FILE/JSX_FILE_NAME”;

• Parent component can pass the state variables to child components via props. If need to pass the state variables to the same level component, need to lift the state property up. A parent can pass the state to all the children.
  The props can be accessed by child via,

          this.props.passedEventName

          So altogether, references are passed through component include block downwards.

• Instead of using class, a simple stateless functional component can also be used so that a simple component doesn’t neccessarily need to have class. 

const NavBar = () => {

      return (

           <nav className=”navbar”>.....</nav>

     );

};

         This should be exported.

         export default NavBar;

• Lifecycle hooks of each component can be used to hook certain events. There are three life cycle phases: mount, update and unmount. Each has its own hook. Following are the most commonly used lifecycle hooks:

• Constructor of the parent class is called using
  super()

class App extends Component {

constructor(){

     super();

   }

}

• ComponentDidMount is the best place to get data from server by making ajax request. Can simply call it inside the component class as a function like

ComponentDidMount(){

   //script to run after mounting the component

}

• Render method is the method where we play along with our html doms to manipulate. When a component is rendered, all its components are rendered recursively.
• Lifecycle hooks can not be used in stateless functional components
• ComponentDidUpdate() of  Update phase is the best place to detect any requirement like if we need to load more data by calling ajax to server.
• componentWillUnmount() can be used to remove any event listener or other cleanups for that particular dom before deleting it from dom tree.

The rpms packaged by MySQL team works well for RHEL and variations of it like centos. cPanel has their own packaging for it though. So if we install rpms directly from third party like mysql, they will get conflict with their custom rpms that they manage to communicate. 

When such an issue comes, after you are done with regular updates in normal way, run this

/usr/local/cpanel/scripts/check_cpanel_rpms

This will check which rpms are missing from the system, which ones got conflict and which ones need repair or reinstall. They have managed excellent scripts to do all this checking. If any of conflicts as below is encountered:

file /usr/share/mysql/mysql_system_tables.sql from install of MySQL56-server-5.6.35-1.cp1156.x86_64 conflicts with file from package MySQL-server-5.6.44-1.el6.x86_64

If we try out some updates from the WHM GUI, errors like this will be shown:

Problems were detected with cPanel-provided files which are RPM controlled…

The solution for issues like above it is very simple. Just remove your conflicting rpm packages by

rpm -e MySQL-server-5.6.44-1.el6.x86_64

We are safe here to do so because conflicting package is of almost the same mysql version and we don’t need to do mysql_upgrade for the schemas to update. If the version is different in major releases like 5.1.X, 5.5.X, 5.6.X and 5.7.X, we will need to make sure the rpms are updated the upgrade of schema is performed by running

mysql_upgrade

With username and password.

After that just remove those conflicting rpms and let intelligent cPanel script check missing rpms and perform an install or repair for you by running

/usr/local/cpanel/scripts/check_cpanel_rpms --fix

This will install those missing rpms from their own server that exactly match with their custom dependant package. At  the other side your service is also updated. 

To start a new project

ng new project-name 

• The Angular CLI has its own lightweight web server that angular compiles. By default, the port 4200 is used by angular web server.

ng serve

• The root has node_modules folder, which stores all the third party libraries. The src folder has the actual source codes of the project.
• The execution starts at main.ts file of the root. The html block that is main.ts will serve is index.html in the root. Package.json file in the root lists out all the dependencies and modules. The typescript compiler setting is in tsconfig.json file there in the root. Typescript compiler converts the typescript to javascript so that web-browsers can understand them.
• The tiny web server of angular CLI uses webpack that automatically bundles all the js and css files. That includes compression and merging to a single file. So unlike the traditional CMS like wordpress which we have to do some extra work for it, here in angular, It does this automatically. If any html of typescript code is changed, the web server automatically detects it,restarts the server and refreshes the browser automatically.
• AngularJS first came in 2010. It was later updated with typescript implementation and more structured and easy for developers. They call it Angular. So the major change is only from version 1 and later. The Angular 2 and later are just minor updates and fixes. To simply term it, AngularJS is for version 1 and Angular simply denotes version 2 and later.
• VSCode is better for Angular applications in terms of auto correction, auto import plugin, shortcuts and syntax highlighting (actually to most of all other javascript frameworks).

TypeScript Fundamentals

Angular uses TypeScript for scripting. Here are some fundamentals of it:

• It’s an extension of javascript. Every script of javascript are a valid typescript. So it can be termed as superset of javascript.
• It has type casting before declaring variables, though not necessarily. Its object oriented i.e it uses classes, constructors, private/public methods etc.
• Typescript transpiler should be installed through npm

npm install typescript

The transpilation can be done by running the command

tsc filname.ts

This creates a .js file in the same folder with same name but as .js extension. When compiling the angular application, this happens automatically under the hood so that browsers can understand.

Things that are in Typescript but not in Javascript

• By default, Typescript generates ES5, which is the oldest version of javascript, supported by all browsers. (later version are ES2016, ES2017…). Let keyword is supported after 2015 version, which may not be supported by some older browser versions. 
• Typescript compiler reports error but still tries to generate valid javascript code
• Type Assertions i.e to explicitly tell the compiler the type of variable  can be done by two ways 

let message;

message = ‘abcd’

let ct = (<string>message);

Or

let ct = (message as string); 

• To define a function, it is not necessary to write the word function, instead can use arrow function

let c = function(p){

console.log(p)

}

The above function in typescript can be replaced with arrow function as

let c = (p) => {

console.log(p)

}

This way, the code is cleaner.

• If you are familiar with PHP, the classes, methods and properties usage are exactly the same. Initialize the class with new keyword and call the members with. The properties inside class is accessible via this keyword.
• Declaring constructor function is absolutely similar to PHP. the constructor() is reserved function inside the class. Adding ? in constructor parameter make it optional.

class human{
leg: ‘2’;
hand: ‘3’

constructor(leg ?: number){
}
}

• The access modifiers are private, public and protected. The usage and meaning are exactly the same way. 

class human{
private leg: ‘2’;
public hand: ‘3’

constructor(leg ?: number){
}
}

let John = new human();

• The access modifiers can be used directly inside constructor
• To export the class to use outside of the file, use export keyword

export class human{
private leg: ‘2’;
public hand: ‘3’

constructor(leg ?: number){
}

}

To import

import {CLASS_NAME} from ‘RELATIVE_PATH/MODULE_OR_FILENAME’;

MODULE_OR_FILENAME should be without .ts or without typescript extension.

• Class, method, attributes etc can be exported from a component (a file) and be used in other component (file) like the way stated above.
• Each component has html markup. The custom element is defined and attached inside the component.
• Components can be generated using angular CLI
  ng g c hero

import { Component, NgModule, OnInit } from '@angular/core';

import { BrowserModule } from '@angular/platform-browser';

import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';

class Hero {

  id: number;

  name: string;

}


@Component({

  selector: 'app-root',

  template: `

      <h1>{{title}}</h1>

      <pre>{{heroes | json}}</pre>

    `,

  styleUrls: ['app/app.component.css']

})


@NgModule({

  imports: [BrowserModule],

  declarations: [AppComponent],

  exports: [AppComponent],

  bootstrap: [AppComponent]

})

export class AppModule {}

platformBrowserDynamic().bootstrapModule(AppModule);

const HEROES: Hero[] = [

  { id: 1, name: 'Bombasto' },

  { id: 2, name: 'Tornado' },

  { id: 3, name: 'Magneta' }

];


function getHeroes(): Promise<Hero[]> {

  return Promise.resolve(HEROES); // TODO: get hero data from the server;

}

It will then automatically generate all the basic necessary files for you in a separate directory on the current directory. It will also automatically update app.module.ts file, which is the main file to register all the modules in the application

• The beauty of Angular is the data-binding. The dom value of a variable is automatically updated if the variable value is updated. This is done internally by the angular framework. Variables can be displayed in the template by using the two curly braces:

{{ the-variable }}

This curly brace also accepts strings to concatenate with the variable using + operator as in normal javascript concatenation. This even accepts the function call from there that is defined inside the class of the component.

• Backticks can be used in template string (string implementation, not .html template) to make multiline 
• The event handling is done by old angular way, eg: for button click

<button (click)=”myFunc()” ></button>

myFunc is the function defined inside the component class for this specific component.

Input field can be bound with # method. Can be passed into the function on click event like this:

<input type=”text” #username />

<button (click)=”myFunc(username.value)” ></button>

This will need to import forms module