What is GraphQL?

GraphQL is an application layer server-side technology which is developed by Facebook for executing queries with existing data. GraphQL can optimize RESTful API calls. It gives a declarative way of fetching and updating your data. GraphQL helps you to load data from server to client. It enables programmers to choose the types of requests they want to make.

What is REST?

REST is a software architectural style that defines a set of constraints for creating web services. It is designed specifically for working with media components, files, or hardware device. The full form of REST is Representational State Transfer.

KEY DIFFERENCES

• GraphQL is an application layer server-side technology that is used for executing queries with existing data while REST is a software architectural style that defines a set of constraints for creating Web services.
• GraphQL can be organized in terms of a schema whereas REST can be arranged in terms of endpoints.
• The development speed in GraphQL is fast while the development speed in REST is Slow.
• The message format for GraphQL mutations should be a string while the message format for REST mutations can be anything. GraphQL uses metadata for query validation whereas REST does not have machine-readable metadata cacheable

Example: gihub

Data Lake vs Data Warehouse

Apache web server running on an Amazon Elastic Compute Cloud (Amazon EC2) Linux instance is intermittently unresponsive and freezing. After checking log file:

$ sudo su

$ vi /var/log/messages

Out of memory error was found.

read

We finished the project for Maxi Kids furniture distributor in Chicagoland: 
maxikidffurniture.com

AtomicInteger

The package java.concurrent.atomic contains many useful classes to perform atomic operations. An operation is atomic when you can safely perform the operation in parallel on multiple threads without using the synchronized keyword or locks as shown in the previous article.

Synchronized

In the previous article we've learned how to execute code in parallel via executor services. When writing such multi-threaded code you have to pay particular attention when accessing shared mutable variables concurrently from multiple threads. Let's just say we want to increment an integer which is accessible simultaneously from multiple threads.

The Concurrency API was first introduced with the release of Java 5 and then progressively enhanced with every new Java release. The majority of concepts shown in this article also work in older versions of Java. However my code samples focus on Java 8 and make heavy use of lambda expressions and other new features.

If your Linux service is not running?

Our task is service checking and restart that service if it's not running.

Functional Programming in Java 8 with Functions

In general terms, functional programming is a programming paradigm, and it’s about programming with functions. What functional programming may be opposed to is the imperative programming paradigm. In imperative programming style, programs are composed from elements that “do” something. “Doing” something generally implies an initial state, a transition, and an end state. This is sometimes called state mutation. Traditional imperative-style programs are often described as a series of mutations, separated with condition testing.