Lucene - Dev & DevOps

  I. AWS Budget Setup Bills Free tier To get alerts about your upcomming costs, the best thing to do is to go into creating an AWS Budget. II. EC2 basics. 1. Amazon EC2. EC2 is one of the most popular of AWS's offering. EC2 = Elastic Compute Cloud = infrastructure as a service it mainly consists in the capbility of: Renting Virtual machines (EC2) Storing data on virtual drives (EBS) Distributing load across machines (ELB) Scaling the services using an auto-scaling group (ASG) Knowing EC2 is fundamental to understand how to Cloud works 2. EC2 rizing & and configuration options. Operation System (OS): Linux, MacOS, Window. How much compute power & cores (CPU)? How much ramdom-access memory(RAM) How much storage space: Network-attached (EBS &EFS) hardware  (EC2 instance storage) Network card: speed of the card, Public IP address. Firewall rules: security group Bootstrap script ( configure at the first launch): UC2 User Data 3. EC2 User Data it's possible to bootstrap ...

 I. IAM introduction: Users. Groups, Policies 1. IAM: Users & Groups IAM = indentity and Access Management, Global service. Root account create by default, shouldn't be used or shared (not best practice to use the root account) Users are people within organization, and can be grouped. Groups only contain users, not other groups. Users don't have to belong to a group, and user can belong to mutiple groups 2. IAM: Permissions Users or Groups can be assigned JSON ducuments called policies. These policies define the permissions of the users In AWS you apply the least privilege principle: don't give more permissions than a user needs. II. IAM Users & Groups Hands On create User  create or select one Group existed III. IAM Policies A policy is an object in AWS that, when associated with an identity or resource, defines their permissions. Permissions in the policies determine whether the request is allowed or denied. AWS Document :  Policies and permissions in IAM 1...

I. AWS cloud overview - Regions & AZ AWS Cloud Use Cases AWS enables you to build sophisticated, scalable applications Applicable to a diverse set of industries. Use cases include  interprise IT, backup & storage, big data analytics website hosting, Mobile, social Apps. Gaming AWS global infrastructure About AWS Regions: AWS Regions AWS has Regions all around the world. Name can be us-east-1, eu-west-3, ... A region is a cluster of data centers. Most AWS services are region-scoped. How to choose an AWS region? Compliance with data governance and legal requirements: data never leave the region without your explicit permision. Proximity to customers: reduce latency. Available services within a region: new service or new features aren't available in every Region. Pricing: varies region to region and is transparent in the service pricing page. About Availability Zones: Each Region has many availability zones ( usually 3, min 3, max 6). Example:  ap-southeast-2a ap-sou...

I. What is Nodejs ? Nodejs is an open source, cross - platform Javacript runtime enviroment. it is used as backend service where javascript works on server -side of application. II. How does it work? There are three main components we must understand to see how Node.js works. These components are:      V8 Engine   Node.js run on chrome v8 engine which convert javascript code into mechine code. The V8 engine contains a memory heap and call stack. They are the building blocks for the V8 engine. They help manage the execution of JavaScript code. The memory heap is the data store of the V8 engine. Whenever we create a variable that holds an object or function in JavaScript, the engine saves that value in the memory heap. Whenever the engine is executing code and comes across any of those variables, it looks up the actual value from the memory heap. The call stack is another building block in the V8 engine. It is a data structure that manages the order of functions t...