NodeJS Cluster | PM2, RabbitMQ, Redis | Full Episode

As we all know, Node JS is single threaded event-driven JavaScript runtime. When we run any CPU intensive operation, Node will not be able to take an advantage of all the cores of our machine. This is where we will use Node JS cluster to run Node JS in multiple cores.

Why Node JS cluster is important?

How to create Node JS cluster application?

Using PM2 to run Node JS application

Communication between Master process and Child Process

Communication between Master process and Child Process using PM2 and RabbitMQ

Working with Redis cache

Using Nginx as a reverse proxy and load balancer

At the end of this course, you will be ready to use Node JS cluster with PM2, RabbitMQ, Redis and Nginx.

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Buddha Community

Redis Transactions & Long-Running Lua Scripts

Redis offers two mechanisms for handling transactions – MULTI/EXEC based transactions and Lua scripts evaluation. Redis Lua scripting is the recommended approach and is fairly popular in usage.

Our Redis™ customers who have Lua scripts deployed often report this error – “BUSY Redis is busy running a script. You can only call SCRIPT KILL or SHUTDOWN NOSAVE”. In this post, we will explain the Redis transactional property of scripts, what this error is about, and why we must be extra careful about it on Sentinel-managed systems that can failover.

Transactional Nature of Redis Lua Scripts

Redis “transactions” aren’t really transactions as understood conventionally – in case of errors, there is no rollback of writes made by the script.

“Atomicity” of Redis scripts is guaranteed in the following manner:

• Once a script begins executing, all other commands/scripts are blocked until the script completes. So, other clients either see the changes made by the script or they don’t. This is because they can only execute either before the script or after the script.
• However, Redis doesn’t do rollbacks, so on an error within a script, any changes already made by the script will be retained and future commands/scripts will see those partial changes.
• Since all other clients are blocked while the script executes, it is critical that the script is well-behaved and finishes in time.

The ‘lua-time-limit’ Value

It is highly recommended that the script complete within a time limit. Redis enforces this in a weak manner with the ‘lua-time-limit’ value. This is the maximum allowed time (in ms) that the script is allowed to run. The default value is 5 seconds. This is a really long time for CPU-bound activity (scripts have limited access and can’t run commands that access the disk).

However, the script is not killed when it executes beyond this time. Redis starts accepting client commands again, but responds to them with a BUSY error.

If you must kill the script at this point, there are two options available:

• SCRIPT KILL command can be used to stop a script that hasn’t yet done any writes.
• If the script has already performed writes to the server and must still be killed, use the SHUTDOWN NOSAVE to shutdown the server completely.

It is usually better to just wait for the script to complete its operation. The complete information on methods to kill the script execution and related behavior are available in the documentation.

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Hire NodeJs Developer

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How to Install NodeJS on Ubuntu 19.04

Overview
In this tutorial, you will learn how to install Node onto Ubuntu 19.04 Disco Dingo. We will cover installation from the default repositories and, for those wanting more recent releases, how to install from the NodeSource repositories.

Installing from Ubuntu
The Ubuntu 19.04 Disco Dingo repository includes NodeJS version 10.15. Like most packages found here, it certainly is not the most recent release; however, if stability is more important than features, it will be your preferred choice.

#nodejs #nodejs 10.x #nodejs 11.x #nodejs 12.x #nodejs 8.x

Top NodeJS Mobile App Development Company in USA

AppClues Infotech is one of the leading NodeJS app development company in USA that offering excellent NodeJS development services for web app development. We provide customized and high-quality NodeJS app development services to clients for different industries with advanced technology and functionalities.

Our dedicated app developers have years of experience in NodeJS development and thus successfully deliver cost-effective and highly customized solutions using the robust JavaScript engine of NodeJS.

Why Choose AppClues Infotech for NodeJS Application Development?
• Fast App Development
• Real-Time Application
• JSON (JavaScript Object Notation) in your Database
• Single Codebase
• Lower Cost
• Built-in NPM Support
• Inexpensive Testing and Hosting

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Website: https://www.appcluesinfotech.com/
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Laravel 7 Full Text Search MySQL

Here, I will show you how to create full text search in laravel app. You just follow the below easy steps and create full text search with mysql db in laravel.

Laravel 7 Full Text Search Mysql

Let’s start laravel full-text search implementation in laravel 7, 6 versions:

1. Step 1: Install Laravel New App
2. Step 2: Configuration DB .evn file
3. Step 3: Run Migration
4. Step 4: Install Full Text Search Package
5. Step 5: Add Fake Records in DB
6. Step 6: Add Routes,
7. Step 7: Create Controller
8. Step 8: Create Blade View
9. Step 9: Start Development Server

https://www.tutsmake.com/laravel-full-text-search-tutorial/

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