BlogPost_306

• What's the difference between operational and programmer errors?
• Operation errors are not bugs, but problems with the system, like request timeout or hardware failure.
  On the other hand programmer errors are actual bugs.

• What is ‘event-driven’ programming?
• event-driven programming is a programming paradigm in which the flow of the program is determined by events such as user actions, sensor outputs, or messages from other programs or threads.

• What are ‘worker processes?
• The "Process" which is responsible for processing Asp.net application request and sending back response to the client , is known as "Worker Process". All ASP.NET functionalities runs within the scope of this process.

• Describe how Node.js can be made more scalable?
• The javascript that node runs is single threaded, but a lot of the things you call in node - such as network or file io - run in background threads. See this post for a basic overview: Node is not single threaded
  If you need the gritty details, you should look into libuv which is the 'magic' piece converting threads into event loops: http://nikhilm.github.io/uvbook/basics.html#event-loops
  Additionally, if you need to do something CPU intensive in node itself, you can easily send this to a child process - see http://nodejs.org/api/child_process.html#child_process_child_process_fork_modulepath_args_options for details

• Explain global installation of dependencies?
• The global installation of dependencies in Node. js refers to installing packages and their dependencies globally in your system. By global, it means they are not specific to a particular Node. js project, but they are available on the go throughout your system.

• Explain RESTful Web Service?
• Representational state transfer (REST) is a software architectural style that defines a set of constraints to be used for creating Web services. ... In a RESTful Web service, requests made to a resource's URI will elicit a response with a payload formatted in HTML, XML, JSON, or some other format.
• REST is used to build Web services that are lightweight, maintainable, and scalable in nature. A service which is built on the REST architecture is called a RESTful service. The underlying protocol for REST is HTTP, which is the basic web protocol.

BlogPost_305

• How does Node.js handle child threads?
• Node. js, in its essence, is a single thread process. ... Technically, Node. js does spawn child threads for certain tasks such as asynchronous I/O, but these run behind the scenes and do not execute any application JavaScript code, nor block the main event loop.

• How can you listen on port 80 with Node?
• redirect port 80 to port 3000 with this command: sudo iptables -t nat -A PREROUTING -i eth0 -p tcp --dport 80 -j REDIRECT --to-port 3000 Then launch Node.js on port 3000. Requests to port 80 will get mapped to port 3000. You should also edit your /etc/rc.d/rc.local file and add that line minus the sudo. That will add the redirect when the machine boots up.

• What tools can be used to assure consistent style?
• JSLint 
• JSHint
• ESLint
• JSCS

• List out the differences between AngularJS and NodeJS?
• Angular is written entirely in Javascript.
• Node JS is written in C, C++, Javascript.
• Angular is a single-page client side web application.
• Node JS is a fast and scalable server side application.
• Angular is suited for highly interactive and active web projects.
• Node JS is best suited for small sized projects.

• What are the advantages of NodeJS?
• It's highly useful when scalable and faster application is required. More suited for application like real time collaborative drawing/edit like Google Docs.

• What you mean by JSON?
• JSON stands for JavaScript Object Notation. JSON is a lightweight format for storing and transporting data. JSON is often used when data is sent from a server to a web page.

• Discuss your understanding of Agile so far.
• It's a type of project management process where there's an organization implemented to be able to advance in software development in a faster, more efficient way.

• How is scrum different from waterfall?
• The waterfall model finishes one phase before another phase can begin. Which can lead to getting stuck. SCRUM flows using Sprints. And if something was not finished, you can just push it to the next Sprint. It's more flexible. 

• What are the Three Amigos in Scrum?
• The Three Amigos - normally consisting of BA, Developer, and Tester - is one of the key ways to change the culture of the team to be more Agile, and encourage more collaboration. ... The Three Amigos ensures a common understanding for a story in the team; a session between Product Owner (Business), Developer, Tester.

• What is the “time Boxing” of a scrum process called? Describe, please.
• Timeboxing is allotting a fixed, maximum unit of time for an activity. That unit of time is called a time box. ... Scrum uses timeboxing for all of the Scrum events and as a tool for concretely defining open-ended or ambiguous tasks.
• Timeboxing is allotting a fixed, maximum unit of time for an activity. That unit of time is called a time box. The goal of timeboxing is to define and limit the amount of time dedicated to an activity.

• What are the roles of a Scrum Master and Product owner?
• The product owner and the scrum master, both have the same objective of adding value to project management. However, these two roles are defined very differently from each other. While product owner looks at the project from the customer’s perspective, scrum masters solely focuses on the team and its operations. 

BlogPost_304

• What is “callback hell” and how can it be avoided?
• Also known as the pyramid of doom. If you make callback after callback it can get out of hand. 
• The solution is to design around it. Use modules. Give your functions names. Declare your functions beforehand. Take some times to think about the structure of your code. 

• What are ‘stubs’ in Node.js?
• Test stubs are functions (spies) with pre-programmed behavior. They support the full test spy API in addition to methods which can be used to alter the stub's behavior. As spies, stubs can be either anonymous, or wrap existing functions.

• What are “Streams” in Node.JS?
• Streams are unix pipes that let you easily read data from a source and pipe it to a destination. Simply put, a stream is nothing but an EventEmitter and implements some specials methods. Depending on the methods implemented, a stream becomes Readable, Writable, or Duplex (both readable and writable).

• What you mean by chaining in Node.JS?
• If you meant Method Chaining, it is nothing but a syntactic sugar commonly seen in Object Oriented Languages. In chaining every method return the object, so that we can chain different calls in single line. See the below example for better understanding.

• Explain “Console” in Node.JS?
• The console module provides a simple debugging console that is similar to the JavaScript console mechanism provided by web browsers.
  The module exports two specific components:
  • A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
  • A global console instance configured to write to process.stdout and process.stderr. The global console can be used without calling require('console').

• Explain exit codes in Node.JS? List out some exit codes?
• exit() takes an exit code (Integer) as a parameter. The code 0 is the default and this means it exit with a 'success'. While the code 1 means it exit with a 'failure'. You may use process.

• What is the difference between Cluster and Non-Cluster Index?
• Cluster index is a type of index that sorts the data rows in the table on their key values whereas the Non-clustered index stores the data at one location and indices at another location.

• What are user defined function? What are all types of user defined functions?
• There can be 4 different types of user-defined functions, they are: Function with no arguments and no return value. Function with no arguments and a return value. Function with arguments and no return value. Function with arguments and a return value.