Installing Nodejs and NPM

Nodejs provides JavaScript with a way to optimise single threaded and single CPU core processing. 
NPM is a package manager to deliver applications. Its like yum on Centos linux.

In this case, I am installing Cordova for Android development on Centos 7.4 and it required nodejs along with npm. Hence, this article came along the way.

Step 1: Install Epel repository

$ sudo yum install epel-release  
$ sudo yum info nodejs
It shows nodejs version 6.12.3

Step 2: Install nodejs

Install the development environment then nodejs. This will install together the npm (version 3.10.10)
$ sudo yum --setopt=group_package_types=mandatory,default,optional groupinstall "Development Tools"
$ sudo yum install nodejs

Check installed version
$ node -v
$ npm -v

Step 3: Run Hello World

Create this script and name it as helloworld.js to test on a command line and the web browser.

var http = require('http');

http.createServer(function (req, res) {
    res.writeHead(200, {'Content-Type': 'text/html'});
    res.end('<p>This is <b>Hello World</b></p>');
}).listen(8080);
console.log('This example is my world!');

At a command line, type
$ node helloworld.js

This should display the output on the command line.
Next, open a web browser and type the following url

localhost:8080

Continue with Cordova installation from previous article.

Remove Defunct or Zombie processes

On Linux systems (Centos, Fedora, Ubuntu, Mint, Puppy), a running application is identified by one or more processes. Example when running a document with LibreOffice Writer, the process thats related is oosplash and soffice.bin as can be seen below.

tboxmy  5262  0.3  0.0 299672  3272 ?        Sl   10:17   0:00 /usr/lib64/libreoffice/program/oosplash --writer
tboxmy  5277  3.1  1.1 1273804 89564 ?       Sl   10:17   0:01 /usr/lib64/libreoffice/program/soffice.bin --writer --splash-pipe=5

Shown in bold, the unique process identification (id) are 5262 and 5277 for the two processes. Upon using the command ps xl, it can be seen that process 5277 is spawned by process 5262. Making 5262 a parent to 5277.

What is a defunct process?

A "defunct" processes is referred as a dead process that still hogs memory resources. Its not much a problem having a defunct process, but when the system starts to have more defunct processes, the system can slow down and affect applications.

This defunct or dead process that still lingers on the system is also known as zombie process. Most appropriate, like in a horror flick! You can't kill a zombie that is already dead, so what can you do? Watch the next zombie show and try figuring that out. Luckily, on Linux systems, a zombie doesn't go around attacking or destroying resources. It only lingers on, hogging on to resources once given to it when it was a live process, at one time.

What brings about this zombie? On Linux its mostly due to bad programming that lead to errors and bugs that are not handled by the application itself.

Dealing with defunct process

Don't attempt to bring back to live a zombie process. Seek out the zombie and terminate from the system. Here are commands to handle an example zombie processes (defunct) with process id 5277.

Where are the zombie processes?
$ ps ef |grep defunct
5277 ?        Z      0:01 [example-app] <defunct>

Notice the word "defunct" and status as Z (for zombie) for the process 5277. That, is our zombie. Did you find any zombie's in your system?

The command kill is used to terminate any process and free system resources such a memory (RAM). The problem with zombie processes is that, they are dead, and can't be killed (not most of the time). What is done however, is to identify the parent process (the one responsible for creating the zombie) and terminate that process.

Identify the parent process id (5262) and terminate it.
$ ps -o ppid 5277
 PPID
 5262

$ kill -9 5262
$ ps ef |grep defunct

That is the end of the zombie. In some cases, a zombie might be holding on to a resource and it will take sometime for it to detach (give it a bit of a wait).

There are other methods to look for zombies. E.g. the ps command provides a method of displaying the parent hierarchy as follows;
$ ps xlf |grep defunct

Or in the command top, look at the second line for number of zombie processes.

What if the zombie keeps appearing on a daily basis for the same process? 

This is a problem, but sometimes its not apparent as zombie's live among the running processes without bothering anyone. Let me know if you have other than the suggestions I have list below.

• See if there is a newer version of the application or an alternative (such as different architecture, from a different source) and install. 
• It is possible that the application itself is not the problem. Identify any other related applications or module that is causing this zombie. Then update or find an alternative application to use.
• Report to the application project team for a solution.

Cannot open display Error when using VNC

After opening VNC Viewer on MS Windows 10 and connecting to the Centos 7, the desktop appears as planned. However, there is an error when running some apps such as system-config-printer. The error is

Gtk-WARNING **: cannot open display:1

Good to note that the VNC server was providing the session at display 1 on port 5901. If you are running the display on another port, it wouldn't matter.

Solution:

At the user's terminal (AND as that user NOT sudo or root), add localhost to the xhost permission. Type

$ xhost +localhost

And this allows system-config-printer to run.

Cordova: Accepting user input

What would be the first thing in programming? A simple use of variable and user text input comes to mind. Following the previous post (link here), the Cordova programming environment is set up for Android. The existing files will be edited to do the following;

The HelloWorldApp when started, will prompt the user to enter a city name.

The user enters a city name and press "OK" button. The city name will be displayed on the app.

Step 1. Position the text to display user response.

Using a text editor, open the file index.html in HelloWorld/www and replace the previous <p> tag with the text "Hello World" with;

<div id="answer"></div>

Save the file.

Step 2. Prompt user at apps startup and display the reply.

Open the file index.js in HelloWorld/www/js

Add our function called getAnswer to the end of the file;
function getAnswer() {
    var ans = prompt("Name your city");
    if (ans.length > 0) {      
        document.getElementById('answer').innerHTML = "";      
        document.getElementById('answer').innerHTML = ans + " is a great place.";
    } else {      
        getAnswer();
    }
}

Activate the getAnswer function in the initialize:function( )by adding after document.addEventListener(...);

getAnswer( );

Step 3. Build and launch the app.

At the command line interface (CLI) or the command terminal, type

$ cordova build android
$ cordova run android

This will launch the default emulator.

In order to test the app, at any time after editing to the source files, just follow this Step 3.

Troubleshooting

Android emulator error: 
The connection to the server was unsuccessful. (file:///android_assets/www/index.html)

Edit the file config.xml in HelloWorld folder. Add the following line after the </platform> tag.

<preference name="loadUrlTimeoutValue" value="700000" />

Build and launch the app.

How to Install Cordova for Android Development

One challenge in developing a mobile application is in choosing a mobile environment. Apache Cordova allows building of an application through the use of Java for Android, AngularJS, SCSS to create reusable code across platforms. I suggest that some study is done on those languages in order to fast track learning. Cordova supports several development platforms, for this article, its focus is on Android platform.

Cordova Installation

Here are the steps to get started on a command line with installation of Cordova and launching the Android emulator on MS Windows 10 (version 10.0.16299). All the versions mentioned here are those that I am using for this article.

1.Install Base Environment

Cordova relies on well known development tools to generate the latest mobile application. Install Java Development Kit (version 8 or newer), Android studio, Node.js and git. Ensure all these are working.

1. Java Development Kit. This should be version 8 or newer and configure JAVA_HOME.
2. Android Studio (This article is version 2.3.3). Install the required SDK platform (I choose Android 7.1.1 Nougat), SDK Tools comprising of Android SDK Tools (version 26.1.1), Android SDK Platform-tools (version 27.0.1) and Android Support Repository (version 47.0.0). In SDK Tools, install Android Emulator. On MS Windows platform, also install HAXM (I have version 6.2.1).
3. Node.js. This article is version 6.9.1 with npm 3.10.8. 
4. Optional: GIT (version 2.8.1.windows.1)

Ensure environment variables are configured for JAVA_HOME and ANDROID_HOME

Then at the command prompt type (do not type the dollar sign);
$ npm install -g cordova

On linux
$ sudo npm install -g cordova

2. Creating Hello World App.

We will create a Cordova project in a folder HelloWorld. This will be in io.cordova.project with the app title of HelloWorldApp.
$ cordova create HelloWorld io.cordova.project HelloWorldApp
$ cd HelloWorld

Here is the syntax to create any project
cordova create [project_name] [package_name] [apk_name]

Open the folder platforms, notice it is empty.

Cordova Project folder for HelloWorld

Open and identify the codes in index.html located at
HelloWorld\www

In HelloWorld\www edit index.html to display Hello World. At end of the app tag, add 1 line
<div class="app">


<p>Hello World</p>
</div>

3. Install Android Platform.

When it is the first time creating a project, the target platform has to be added. Here its created in a folder CordovaProject.
$ cordova platform add android

Have a look at the Android source files are located at MainActivity.java in

HelloWorld\platforms\android\app\src\main\java\io\cordova\project

Default MainActivity.java file

Each time the apps code is modified, the project is compiled and run in an emulator OR on a mobile device. Compile and build the project for the Android platform.
$ cordova build android

Start the apps in an emulator. The default emulator manager is by Genymotion and the default emulator is Pixel with Android API 25.
$ cordova emulate android.


If you intend to plug in your Android device to run the app, or  start the apps in an external device, type
$ cordova run android

4. Tips

List existing platform installed and what platform is available.
$ cordova platform ls

Apache not sending emails on Centos 7

Applications on Apache webserver that are working fine but can't send out emails is a real headache. Especially if everything was working on the development server. Example of error encountered;

Could not execute: /usr/sbin/sendmail

In Wordpress, it refuses to send email. Once such instance is the Forget password window and you see the message
The e-mail could not be sent.
Possible reason: your host may have disabled the mail() function.

This is ONE possibly most common situation. 

On most Development servers, the SELinux is probable turned OFF or in permissive mode. However on the Production servers, they are almost always set to ON. In the web server document directory, check if the following SELinux status;

$ getsebool httpd_can_sendmail

It should be in status OFF. Change the status to ON and restart Apache with the command

$ setsebool -P httpd_can_sendmail on
$ systemctl restart  httpd.service

Second common situation

Still not receiving emails from apache or Wordpress? It is possible Postfix SMTP server is using values that the email relay SMTP is not accepting. Check the maillog for any errors such as this;

said: 450 4.1.8 <apache@production.localdomain>: Sender address rejected: Domain not found (in reply to RCPT TO command))  

Or

sendmail[2450]: NOQUEUE: SYSERR(apache): /etc/mail/sendmail.cf: line 0: cannot open: Permission denied

This is a story for another time.

Install Linux on Samsung NP150 Plus netbook - Part 1

Installation of Linux Mint 18.3 (Sylvia) Xfce 64-bit on Samsung NP150 Plus netbook. This is how I installed a dual boot of Linux Mint 18 on existing MS Windows 10 Home (Upgraded from MS Windows 7 Starter).

This little netbook runs on  1.66-GHz Intel Atom N450 processor with 1Gb of RAM and an x64-based processor. I am giving it a shot to see if its possible to install Mint and usability as a school student's laptop. Linux Mint is a project spun off from Ubuntu with a large library of applications. Version 18.3 is based on Linux kernel 4.4 with Ubuntu package on 16.04 and will receive security updates until 2021. Xfce is an open source software to provide a light weight desktop for low processor computers. See Whats new for more details.

Linux Mint Xfce vs (Cinnamon) 

Minimum requirement:
9Gb (20Gb) Disk space
1024x767 resolution (lower resolution require press Alt drag windows with mouse to fit monitor)
512Mb (2Gb) RAM

Linux Mint 18.3 with Xfce desktop

Installation

Linux Mint can be downloaded from linuxmint.com. Download then create a bootable Linux Mint on the USB disk. I used Rufus version 2.18.1213 (See error below when using Win32diskimager version 1.0.1) to extract the ISO file into the USB disk. File system on Rufus MUST be set to FAT (Default) with cluster size 64 kilobytes (Default).

(A) This netbook comes with MS Windows 10 Home Windows 7 Starter and a small capacity hard disk. Firstly create free space by using the apps in MS Windows.

1. Open MS Windows Explorer. Right click "This PC" -> Manage.
2. Choose Storage ->Disk Management
3. Choose the unused disk partition and resize to 50Gb of free space. More would be better.

Choose "Manage" to access the Partition tools.

On some disk, it will need to "optimise disk" to reclaim more free space.

(B) Boot from USB disk

1. Shutdown netbook. Plugin the Mint on USB disk into the netbook. 
2. Boot netbook and press F2 to enter BIOS 
3. Choose to boot USB HDD before the AHCI HDD
4. Save and reboot.

Samsung N150 Plus BIOS screen to boot from USB Disk.

Note: Win32diskimager 1.0.0 to create USB Disk.
The Linux Mint boot up screen appears at first boot but ended up with following message.

32-bit relocation outside of kernel!
-- System halted

This is solved by formating the USB disk as FAT, then run Win32diskimager.

Note: Hangs after boot screen. 
Reboot then at the Linux mint boot screen, Choose first option "Linux Mint" and press TAB. Remove the text "quick splash" and press Enter. This reveals the error;

Uncompression Error
-- System halted

This is resolved by using a larger capacity USB disk. Initially it was a 2Gb USB stick then changed to a 4 Gb USB disk.

Its booting! Will continue with further post next time.

Linux Mint 18.3 Installed on N150 Plus

For now, the partition table plan as follows;

/  -  20000MB
swap  -  2
/home  -  Remainder space

What's new in Firefox Quantum (screens)

Firefox 57, also known as Quantum is a major upgrade for Firefox web browser. Here are initial screens of this new web browser compared to previous version of Firefox 56.






Tools menu






Toolbar


Preferences
 

Speedtest



Speedtest Ranking

Laravel and using custom CSS file

Laravel 5 supports CSS and JavaScript preprocessors through Elixir and Gulp. Elixir is a node.js tool that helps gulp in the use of less, sass and coffee methods. Gulp assist programmers by automating repeated task like copying files, testing, minify codes.

If all that sounds confusing, dig deeper and you will find that Laravel framework assist developers to build and test application faster through tools like Elixir and Gulp.

There will be cases where an existing and proven CSS file should be used within a Laravel 5 project. In this example, there is a CSS file name beautiful.css that provides a box when used in the DIV CLASS code of the php application as shown below;

<DIV class="beautiful-tip">
 <P>Hello World</P>
</DIV>

We will use an existing working Laravel 5 application that is installed at the folder named <project>. In the gulpfile.js, the mix.sass contains 'app.scss' where instructions to use the CSS will be recorded.

Step 1: Copy the CSS file to Project's node_modules folder

Create the folder "example" in <project>/node_modules
Copy beautiful.css into the folder <project>/node_modules/example and make sure the folder and its contents are readable by the web server service.

Step 2: Include the CSS file when gulp compiles SASS files.

Edit <project>/resources/assets/sass/app.scss

At the last row, add the command (name of CSS file without its extension) and save.
@import "node_modules/example/beautiful";

Step 3: Run gulp.

At a command prompt in the project folder, type

# gulp

Done

Can anyone use OSS in their product?

Use of open source (OSS) licensed software have gained widespread acceptance. Its no longer just for hobbyist and academic studies. R&D takes place much rapidly with these open knowledge available to masses but its very different from just copying the software when corporations and industry adopts OSS in their product.

Ever wonder why anyone would allow their codes formed from sweat and sleepless nights to be made available to everyone? Broadcom for example, provide their source codes and its become such a powerful references. Something to ponder, but lots of articles are around to help one understand.

If you intend to use OSS as part of a product that is sold (not the services) or distributed freely, there is the GPL and LGPL type of licensing type of OSS. A brief if not too broad explanation on the differences.

Products bundled with GPL type licensed OSS components and codes must distribute with the source code made available to the product recipient. Lets say, you develop a smart desktop suite called P99SmartDS that incorporates modified Mozilla Thunderbird to handle smtp and pop messaging to the desktop. Thunderbird expects you to ship the P99SmartDS with working source code and be licensed not more restrictive than that GPL licensed.

Products bundled with LGPL type licensed OSS component and codes must distribute with the license and library of that specific OSS component. Lets say, you develop a wireless driver interface and application to simplify configuration and its using a LGPL licensed OSS library. This application does not have to be OSS licensed.

Selling a product base on OSS is not just about submitting bugs or chats in forums. It sharing of knowledge gain via successful products. The OSS licensed is the guardian to ensure continuity of the freedom of choices and knowledge. Play your part to safe guard this freedom.

Laravel 5 and OpenSSL

Notes on updating Apache 2.4, Laravel 5.5 with PHP 5, to PHP 7.1. 

Currently, the openssl key on my Apache server is serving encryption with AES 128. Information here is for development server environment only.

Default new Laravel applications are generated with use of encryption key type AES 256 as found in <Laravelproject>/config/app.php

The cipher key in app.php can be changed, or just generate the new required AES 256 keys.

Steps to generate the OpenSSL public and private keys;

$ openssl genrsa -aes256 -out mysitename.key 2048
$ openssl rsa -in mysitename.key -out mysitename-decrypted.key
$ openssl req -x509 -nodes -new -sha256 -key mysitename-decrypted.key -out mysitename.crt


When restarting Apache on MS Windows 10, this error appears.
"Init: SSLPassPhraseDialog builtin is not supported on Win32"

Solution is to remove the pass phrase in private key (See). In this example, the public and private ssl certs are both stored in <Apache directory>/conf/ssl/
Step 1:
Copy private key mysitename.key to secure.key

Step 2: Remove pass phrase from private key in use.
In CLI of the folder for ssl type

$ openssl rsa -in secure.key -out mysitename.key

Step 3: Open <Apache directory>/conf/extra/httpd-ssl.conf and comment out the line
# SSLPassPhraseDialog  builtin

Step 4: Restart Apache

In the event the following error appears, it means the openssl module is not loaded. Find another compatible Apache server to be installed that can load the openssl in directory extension.

PHP Startup: Unable to load dynamic library
or
Undefined method openssl_cipher_iv_length( )

Laravel non-existent script error

Recently updated to PHP 7.1 and all the existing PHP projects are working fine.

However, this error appeared when I am trying to create a new Laravel 5 project,

You made a reference to a non-existent script @php -r "file_exists('.env') || copy('.env.example', '.env');"
Loading composer repositories with package information
. . .

You made a reference to a non-existent script @php artisan key:generate

Lets fix this in one step;

Step 1: Update the composer,

$ composer self-update

Updating to version 1.5.2 (stable channel).
    Downloading: 100%
Use composer self-update --rollback to return to version 1.2.2

Run the command used to create the new project,

$ composer create-project laravel/laravel myapps

Android AlertDialog

How to display a delete confirmation box?

A simple method is to use AlertDialog that quickly provides the "CANCEL" and "OK" along with your custom confirmation message.

An example within a Fragment class where a user click's the Delete button which calls the deleteConfirmation( ) function with the title or name of item to be delete.

1:  private void deleteConfirmation(String title){  
2:    AlertDialog.Builder alert = new AlertDialog.Builder(getContext());  
3:    alert.setTitle("Delete");  // Declare the title
4:    alert.setMessage("Are you sure you want to delete \n"+title+"?");  // Set message below title
5:    alert.setIcon(R.mipmap.ic_delete);  // Set the icon at top left
6:    alert.setPositiveButton(android.R.string.yes, new DialogInterface.OnClickListener() {  
7:      public void onClick(DialogInterface dialog, int which) {  
8:        // continue with delete  
9:        MainActivity.confirmDelete=true;  
10:        delete();  
11:      }  
12:    });  
13:    alert.setNegativeButton(android.R.string.no, new DialogInterface.OnClickListener() {  
14:      public void onClick(DialogInterface dialog, int which) {  
15:        // close dialog  
16:      }  
17:    });  
18:    MainActivity.confirmDelete=false;  
19:    alert.show();  
20:  }  

Note 1:
The Dialog class is the base class to AlertDialog that makes the user take an action before returning back to the Fragment or Activity. This is known as a Modal Event. Other example of Dialog class are DatePickerDialog and TimePickerDialog.

If used for Android API 25 and onward, the import statement is

import android.app.AlertDialog;

for API 11 to below API 25 use

import android.support.v7.app.AlertDialog;

Note 2:
There are 3 type of buttons that can be added (in the example above, only 2 are added) to an AlertDialog. Only one of each type can be added using the following methods;

alert.setPositiveButton
alert.setNegativeButton
alert.setNeutralButton

List can be added to AlertDialog if required.

Note 3:
There are several ways to pass message or status to the Activity or Fragment that created/launched the AlertDialog. In the example above, a static variable is declared in the MainActivity and values are changed base on button clicked.

In MainActivity.java

public static boolean confirmDelete=false;

Note 4:
To further customise the AlertDialog look, a resource file (XML) can be created and assigned with the method

LayoutInflater inflater = getActivity().getLayoutInflater();
alert.setView( inflater.inflate(R.layout.customDialog, null) )


Done.

Raspberry Pi Workshop 2017 (Java)

Java is still very much alive today despite the many new programming languages sprouting. This portable language provides programming solution for a wide variety of computer systems including embedded devices.
As for the Raspberry Pi, the most common operating system being in use is Raspbian which comes default with Java installed. The Raspberry Pi provides a physical extension that connect to sensors and other electrical components. There are 2 most common Java libraries being used to accessed these extensions. Each having their own strengths.

In Malaysia, organisations can accelerate their learning path in this area through a 1 day fully hands-on comprehensive workshop. Details can be found the SHOP section of Harmony Shades or leave a message with details of your interest.

MySQL Console Pops Up Unexpectedly

MySQL database server provides an easy to implement and uses ANSI SQL syntax with wide implementation for many programming platforms. It is still open source licensed for the Community Edition as GPL (see details at mysql.com).

Current versions of MySQL Community Edition is available on Red Hat 6+, Centos 6+ and MS Window 10, for following versions;

• MySQL 5.6 GA on 5.2.2013
• MySQL 5.7 GA on 21.10.2015

Both versions are known to support current SQL standards, being SQL:2008.

Since using MySQL Community Edition version 5.6.21, something strange has been happening every midnight. A DOS like prompt pops up and very quickly does "something", which does NOT really allow me the time to read the messages and then it goes away (disappears). On one occasion I managed to capture that screen as the database it was trying to reach was not connected and here is how that screen looks like.

Apparently it was updating the MySQL catalogue, pretty harmless. The problem that I can see;

• Takes up additional processing which is not good when I am running emulators or CPU intensive work
• Distracts any on going work, such as when preparing documentation
• Disrupts desktop on-going recordings
• Disrupts benchmark operations

One could either disable the update process or assign it to another pre-defined time. On MS Windows 10, here are the steps to do either.

Step 1: Start MySQL Installer

Click the MS Windows Start and type; mysql installer
Click the Desktop App that appears. An upgrade my be required, proceed with the upgrade.

Step 2:  Edit Installer Options

In the installer option, click the Configure icon (Looks like a wrench).

1. To disable the automatic catalog update; Uncheck "Should MySQL Installer update its catalog periodically?"
2. To change the update time; Select a new time in "What time?" dropdown list.

Click Close.

Done.

Source code revision control with Git

Version control system is used to manage versions of files and is used widely with programming source codes. Common examples are SVN and Git.

Here is an example of the using GIT with Heroku (Working with GIT2). It demonstrates the git command for;

• clone
• branch
• checkout
• commit
• status

Basic commands to manage a local version control repository

Typical process to prepare a folder where files are to be tracked/staged uses the commands init, status and add. It would be good to have created a folder with 4 or 5 files and try out the following commands.

 # Initialise Git repository   
  $ git init   
     
  # Identify status and which files are being track or untracked.   
  $ git status   
     
  # Add all files to the repository   
  $ git add .  
   
 # Identify files are being track as staged  
  $ git status   

At this time, a folder to manage the repository is created with the name ".git". Have a look at content of the files in this folder.

Filename: .git/HEAD
ref: refs/heads/master

Filename: .git/config
[core]
repositoryformatversion = 0
filemode = false
bare = false
logallrefupdates = true
symlinks = false
ignorecase = true
hideDotFiles = dotGitOnly

Filename: .git/description
Unnamed repository; edit this file 'description' to name the repository.

To remove a file from being tracked.

 # Remove a file from list of staged files  
 $ git rm --cached somefile.txt.  

Process to place files into the repository.

 # Commit files to repository  
 $ git commit -m "Place comments here"  
   
 $ git status  

Retrieve tracked file from the repository. The latest thats found in the repository, that is.

 # Checkout a file from the repository  
 $ git checkout programming.txt  
   
 $ git status  

Cache and other files that should not be kept in the repository or tracked, can be listed in a file ".gitignore" within that folder. Example to ignore the folder "temp" and file "nofile.txt".

Filename: .gitignore
/temp
nofile.txt

end

Open Source Software Leads Growth of Deep Learning Community

Faster CPU and GPU computers have arrived and AI computing is becoming available to more people. Amazon and Google are already rolling out services that allow anyone access to the computational resources required for AI, in particular deep learning. I am looking forward at how this will be incorporated into the next gen of personal devices.

There are too many areas to discuss on this, but here I would like to mention that deep learning is catching up fast on the open source software (OSS) environment.

GPU deep learning with NVIDIA provides a good start. They even have a whole section devoted to deep learning;

https://www.nvidia.com/en-us/deep-learning-ai/education/

A quick guide on deep learning is available at Deep Learning Introduction.

The Day British Airways System Crashed in 2017

Waiting to hear the cause of it. How difficult is it to start up the back up process?

Source https://www.thesun.co.uk/news/3669536/british-airway-it-failure-outsourced-staff/

Pentaho 7 Community Edition

Summary of their licenses.

With big data and increase interest in business intelligence, there seems to be many software out there to suit all your needs. As for OSS licensed, the name Pentaho have been around for a long time. Here is a little note on their licensing.

Pentaho Business Analytics Platform 2, Pentaho Reporting Engine and Pentaho Report Designer are licensed as GPL v2.

Pentaho Data Integration or Kettle is license as Apache version 2.0. Details are found at  their wiki.

There is an interesting and comforting public post on Kettle license at Pentaho Forum with regards to Pentaho licensing.

Community Edition

Pentaho 7.1 is currently available but there is still the community edition, and my notes on Howto install is available only for the Linux server.

• Howto install Pentaho 7 on Linux

The additional known components that enterprise have and community edition doesn't is the self service designer dashboard and interactive reporting. Still searching for comparison of the community edition and other BI tools in the market.

Mouse Cursor Disappear in Chrome Web Browser

Google Chrome is among the web browsers that I use frequently on MS Windows 10. Chrome provide many standard web browser features, security and option to extend its capability via plugin extensions. Work productivity goes up a notch when many application windows are launched to run concurrently. The monitor screen is big enough to allow re-positioning of the windows, overlapping windows and minimizing of windows.

On 20th April (today), the mouse cursor disappears when its moved over the Chrome window. It appears back when the cursor is moved outside of the Chrome window area. Moving the cursor again on Chrome window area, its noticeable that an invisible cursor is moving as hyperlinks light up, menu and buttons get active and the standard windows minimise and maximise buttons can be accessed.

A quick search on the internet shows that this problem have occurred way back in June 2014. Its almost the same thing, and issue only started after a MS Windows update that had occurred the day before. Yes, there was a Windows 10 updated yesterday.

Solution is to disable the Hardware Acceleration in Chrome. Here is how to get that cute cursor back on Chrome.

Step 1: Open Chrome web browser (if its not already open).

Step 2: Click "Customise and control Google Chrome" or the "3 vertical dots" button. Its usually at same row as the URL bar. Choose "Settings", scroll down and click "Show advanced settings...".

In the section "System" uncheck Use hardware acceleration when available. Close Chrome and launch Chrome or restart Chrome.

I have not found out if its due to MS Windows change in its settings or Chrome settings changed. Maybe someone out there have an answer.