Elastic Search Terminology

Elastic Search terminology : Cluster Node Shards Replicas Index Type Documnent Field Cluster A cluster is a collection of one or more nodes (servers) that together holds your entire data and provides federated indexing and search capabilities across all nodes. Node A node is a single server that is part of your cluster, stores your […]

Async.each in Node.JS

As NodeJS works with single thread, so most of processing is in async mode. But sometimes we face situation where we need to iterate through items in sync manner. For example. ForEach in JS works in async . So using npm module async we can handle things and make code to wait until we have […]

RESTful API and Web Service

What is REST API : A REST API defines a set of functions which developers can perform requests and receive responses via HTTP protocol such as GET and POST. An API can be considered “RESTful” if it has the following features (not a complete list just the main ones): Client–server – The client handles the […]

MySQL Indexing and Internals

A database index is a data structure that improves the speed of operations in a table. MySQL indexing is used to avoid full table scan. An index is a data structure (most commonly a B- tree) that stores the values for a specific column in a table. An index is created on a column of […]

Middlewares in Node.JS

An Express application is essentially a series of middleware function calls. Middleware functions are functions that have access to the request object (req), the response object (res), and the next middleware function in the application’s request-response cycle. Source : https://expressjs.com/en/guide/using-middleware.html Types of middleware functions: Application – level middleware Router – level middleware Error – handling middleware […]

NodeJS Under the Hood

what does it mean by : NodeJS is single threaded non blocking eventdriven framework…. NodeJS works on single thread ie main thread . where as other develoment platforms use multiple threading to process multiple request you can say one thread per request . So by using single thread NodeJS saves a lot of memory. NodeJS […]

MySQL Client and MySQL Server Difference

Source : http://stackoverflow.com/questions/6962890/what-is-the-difference-between-mysql-server-and-mysql-client MySql Client : The mysql-client package allows you to connect to a MySQL server. It will give you the “mysql” command-line program. MySql Server : The mysql-server package allows to run a MySQL server which can host multiple databases and process queries on those databases. MySQL : The “MySQL” package probably includes both […]

REST Webservices

RESTful Web Services are basically REST Architecture based Web Services. In REST Architecture everything is a resource. RESTful web services are light weight, highly scalable and maintainable and are very commonly used to create APIs for web-based applications. REST Architecture : A concrete implementation of a REST Web service follows four basic design principles: Use […]

Understanding NodeJS

What is node js Node.js is a runtime system for creating (mostly) server-side applications. It’s best known as a popular means for JavaScript coders to build real-time Web APIs. Node.js is a platform built on Chrome’s JavaScript runtime for easily building fast and scalable network applications. Node.js uses an event-driven, non-blocking I/O model that makes […]