Igeometry Podcast

Tor or (The Onion Router) is a free and open source project for allowing anonymous communication. In this video I want to discuss this technology and explain how it works. What can sniffers really see? Why Tor? Why don’t we just use a VPN? How Tor Works? More about Tor So if you are interested stay tuned. Cards: 6:00 TLS 10:53 symmetric key encryption TimeCodes: Normal Request 1:30 What sniffers see 4:30 Why Tor and not VPN? 6:00 How Tor Works 8:50 More tor info 21:00 Tor Directory Relay node Exit node Guard node --- Support this podcast: https://anchor.fm/hnasr/support

Apache Kafka is a distributed stream processing software developed by LinkedIn and written in Scala and Java. In this video I want to focus on the basics on Kafka, talk about how it works give finally spin up a kafka cluster and write a producer and a consumer. Kafka Components _ producer _consumer _topic _partition How Kafka works Example ( Ride sharing ) Spin Kafka cluster Write a producer Write a consumer Kafka Applications Pros and Cons --- Support this podcast: https://anchor.fm/hnasr/support

Tom Scott Full Video https://youtu.be/WVDQEoe6ZWY Tom Scott is a YouTuber with around 2M subscribers who discusses and specialized in computer security. I always enjoy his videos specially those on computerphile. He recently made a very interesting video titled This video is sponsor by —- We all probably know this is a reaction video to NordVPN Hack. He is really smart and not just because of his accent I wanted to make a video to elaborate on some of the statements that Tom made in his video and how that actually work. Cards 5:30 TLS https://www.youtube.com/watch?v=AlE5X1NlHgg 12:24 TLS Termination https://www.youtube.com/watch?v=H0bkLsUe3no Forged certificate https://slate.com/technology/2016/12/how-the-2011-hack-of-diginotar-changed-the-internets-infrastructure.html --- Support this podcast: https://anchor.fm/hnasr/support

RabbitMQ RabbitMQ is an open source distributed message queue written in Erlang and supports many communication protocols. It was trying to solve the spaghetti

Redis is a noSQL key-value store, in memory database first that exploded in popularity in the past few years. In this video slash course, we will explain what Redis is, talk about the in-memory model, the optional durability, replication, clustering publish subscribe and the protocol and finally we will go through examples. During the video I will add time codes to each topic so you guys can jump to the topic that interests you the most.    Table of Content and TimeCodes  Redis as a NoSQL In Memory Key-Value store 3:49Optional Durability 10:00Transport Protocol 15:10Pub/Sub 18:24Replication and Clustering 20:40Examples 23:41Spin Docker 26:10Command CLI 28:50Set key 30:30  get key 31:00Set key with expiry 31:10exists key 32:00del 32:30  append key 32:50  publish subscribe 33:30   Commands  Docker run --name redis -p 6379:6379 redis docker exec -it rdb redis-cli    Cards 4:25 ACID!     Support me on PayPal  https://bit.ly/

GraphQL Pros and Cons, examples and when to use over REST GraphQL is an open source query language developed by facebook that allows clients to formulate queries to get different results. Its main goal is to combine multiple services into one endpoint. In this video we will discuss what is GraphQL, why facebook developed it, go through some examples using github GraphQL API, finally we will discuss the pros and cons and when you should use this technology. What is GraphQL? Examples Pros and Cons when to use REST vs GRAPHQL What is GraphQL Schema Query language Nesting Mutation and subscription Examples Schema intro Github API Rest api Pros Flexibility efficient response : payload back only get what you want of fields since you know the schema No round trips- Avoiding multiple round trips (HATEOS REST) Uniform single interface API endpoint Self documenting Cons Complexity Typed system - ( use it to know if a type is available or not and fork logic) slows down adoption.. same

Consistency vs Eventual Consistency Consistency is the property of having expected result in view of the data or during reads while working with a database system. It is one of the ACID properties in relational databases. Eventual consistency is another term that was born recently specifcally as NOSQL databases got emerged. In this video we will talk discuss the difference the different kind of consistencies and we will explain what Eventual consistency and how both relational databases and NO SQL databases have this kind of consistency with some examples. Cache Leader Following Consistency in Data Your data broken into multiple normalized tables/collections is consistent. Consistency in Reads If you write a value new transactions will pick up that new value. If you do not have consistency in data you do not have eventual consistency, your data will not magically correct itself. If you have do not have consistency in reads you might have eventual consistency, you reads might eventually become consistent. Even

  ACID ACID are four properties of relational database, they Atomocity, consistency, isolation and durability, and I think any one working with a relational database like postgres, mysql, sqlserver oracle, should understand these properties. In this video we will go through the four properties and explain why each is critical to make a relational database we will also talk about why some people are moving to  NOSQL database Atomicity  All or none. if a failure happened during transaction, db failure, or one of the queries failed.  Example Isolation Concurrency, is transaction isolated from other inflight transactions? if a transaction is in flight does it see changes from other inflight transactions? Does is it see any changes? Does it only see committed changes. Does leading to inconsistent results.  Problems arising from isolation (read phenomenons)  dirty reads Non repeatable reads Phantom reads  Isolation levels Read uncommitted Read committed  Repeatable read  Serializable  Durability When

  REST stands for Representational state transfer its is an architecture that became very popular in build web APIs. It was the dissertation of Roy Fielding. In this video we discuss what makes an API RESTFUL, the REST APIs constrains, ill the show you an example of a RESTFUL api in github.  Representation and State transfer  Representational  The resource is a representation or meta data, but the actual backend could be something else and stored differently. An  Example, could be a user resource could be represented as a JSON object but it is stored on the backend as relation DBMS tables such as postgres.  State transfer The application server is stateless, and when we want communicate we transfer the current state of with each request. Thus the state transfer.   Example, lets say you are uploading a 5MB file in 5 chunks each is 1 MB in size and assemble it on the backend. The REST api end point takes the content along with a upload sequence, then persist it on a storage ba

A proxy is a software that intercepts traffic and forward it to the destination on behave of the client. This extra layer provide several advantages such as caching, load balancing, content filtering and much more. Some implementations of proxy can be used by governments to spy on its citizens. We made a video about proxy vs reverse proxy check it out if you want to learn more about the difference. In this video we will explain the different types of HTTP proxies and the benefits and use cases of using each coming up.  Transparent proxy (gateway)  HTTP insecure proxy Service Mesh Proxy Transparent proxy It is mostly used by the ISPs, clients don’t know they are connected to transparent proxy. The way it works is it looks at TCP/IP layer 4/3 and forward it to the destination, it might do some content filtering based on the IP address or the port so it blocks certain sites. But thats pretty much it. transparent proxy cannot know which pages are you viewing or your what youtube videos are you watching.

  HTTP is a protocol for transferring web pages, text, media, binary files and much more. It stands for hyper text transfer protocol and It is what the Internet pretty much runs on. In this video we will learn how HTTP works, how it is secured with HTTPS, will also show how to spin up an Http web server, and we will also go through the evolution of HTTP starting from HTTP 1.0 to HTTP 1.1 to HTTP/2 and eventually HTTP/3 which is still experimental.    HTTP anatomy  Request (browser, web app)  URL Method type Headers Body Response (web server)  Status code Headers Body  HTTP 1.0 over tcp Application Layer 7 new connection with each request.  HTTP 1.1 over tcp Persisted connection  HTTP/2 over tcp Compression Multiplexing Server Push SPDY Mostly secure by default Negotiates protocol during TLS (NPN/ALPN) HTTP/2 over QUIC ( HTTP/3)  Replaces TCP with QUIC (udp with congestion control)  --- Support this podcast:

NAT network address translation is a process of mapping an IP address or IP port pair to another IP address or IP: port. You might be wondering what a software engineer like me doing making a video on a low level networking concept? I have good reasons for that. NAT was originally designed to solve the ipv4 limited IP addresses, but since been used for port forwarding and layer 4 load balancing through the virtual ip address such as Haproxy thats why I decided to make a video about NAT from a software engineer view. In this video we will explain how NAT works and we will explain its applications.  --- Support this podcast: https://anchor.fm/hnasr/support

Tunneling protocol Tcp tunneling Tunneling is the process of encapsulating content from a protocol A into another protocol B, usually because protocol A is blocked or unavailable. In this video we will explain how TCP tunneling works, the applications of TCP tunnels and the pros and cons. Coming up! * TCP Tunneling * Applications * Pros and Cons TCP Tunneling Here is how TCP Tunneling works. Lets say your goal is to access a website that your ISP proxy blocks www.server2.com this is hosted on server2 on port 80. Lets say there is another Server1 that you have access to and Server1 have direct access to Server2. So if you can make Server1 make the request on your behave to Server2 and somehow deliver the results back to you, you just created a tunnel between You and Server1. Here is how it actually works. You create a legit tcp connection over a known protocol such as SSH between you and Server1. You then create a tcp packet that is intended for Sever2 so you tag it with Server2:80. Then you packa

  TLS which stands for transport layer security is a protocol for securing communication between client and server. Specifically for HTTPS. Thats what the S is stands for.  In this video, we will learnq how insecure vanilla HTTP works, HTTPS, then we will learn how HTTPS is possible via the transport layer security and finally we will talk about the improvements in 1.3 that was published August 2018.  Vanilla HTTP HTTPS  TLS 1.2 handshake TLS 1.3 enhancements Vanilla HTTP  Before we discuss TLS, HTTPS or anything else lets go through how HTTP request work. You can type in the browser www.husseinnasser.com , the OSI magic kicks in, client figures out the IP address of husseinnasser.com by calling the DNS which uses UDP. Then HTTP application layer makes a GET / request passes in the IP address and port 80 (default for insecure http). This creates an underlying TCP connection. GET / string among other stuff into the packet and send it over. TCP does its thing server receives GET / calls

Encryption is the process of scrambling data to protect personal files, secure communication, hide identities and much more.  In this video we will learn about the different type of encryptions we will talk about symmetric encryption, asymmetrical encryption, where they are used for and the pros and cons of each one.  Symmetric encryption Asymmetrical encrypt  Pros and cons of sym va asym  Symmetric encryption  Might as well just call it classic encryption I would argue and i think this is the first encryption known to us. I have some thing I dont want anyone to see I use a lock key to lock it. Only I can open it unless I have a lock.  The same key you use to encrypt is the same key to Decrypt.  Examples Examples of popular symmetric-key algorithms include  AES Twofish Serpent  DES Twofish, Serpent, AES (Rijndael), Blowfish  CAST5, Kuznyechik, RC4, DES, 3DES, Skipjack, Safer+/++ (Bluetooth), and IDEA  Asymmetrical encryptions  We had symmetric

  Bandwidth explained from software engineer point of view Bandwidth is measured by how many bits a device is allowed to send/receive in a second. It ranges from your internal network starting from network card all the way to your ISP Internet speed. In this video we will discuss the definition of bandwidth upload vs download speed, the different usage patterns for normal web browsing, streaming, gaming, media production and cloud web servers etc and finally we will show an example of the whole thing. When your ISP gives you 80Mbs download/1Mbs upload bandwidth, this means 80 mega bits download which means your router (and all your devices) can receive (download) a total of 80 mega bits in a second at a time, and it can send (upload) 1 mega bit in a second. With your ISP can you pick and choose your plan that fits your usage. Usage patterns Web Browsing Most people download far more than they upload. So the download bandwidth matter more than upload bandwidth. For simple web browsing the download incomin

  Denial of Service attacks Dos attacks (denial of service) are type of attack on a server to prevent users from consuming a particular service, usually this is an HTTP web server. This could happen by either saturating the bandwidth of the pipe going to the server or by bringing the server down to its knees so it stops taking requests all together. In this video we will learn about 3 different types of DOS attacks and explain each one by example.  Bandwidth based DOS 2:15 Dos Sending Huge amount of data to a server with lower bandwidth from a client with higher bandwidth which ends up saturating the server pipe and queue up future requests, new requests will have to wait or perhaps denied service. Example, the attacker have 100mb/s bandwidth (upload) the server has 10Mb/s download. If the attacker starts sending 100 mb worth of data to the server, it will take it 1 second to leave the pipe. However, The server can only download 10 mb each second for processing because thats its bandwidth, so it n

 TCP and UDP are communication protocols that allows us to send and receive data in a network. We have both for a reason since each has its advantages and disadvantages. In this video we will talk about two protocols, pros and cons of each one and will write tcp and udp server with nodejs showing you these in ACTION. coming up Code!  https://github.com/hnasr/javascript_playground/tree/master/tcp Jump Codes

  Get and POST are the most popular http methods used on the web. Each carries its own differences and properties. It can confusing to get to choose when to use POST over GET. In this podcast we will explain the differences, use cases and the benefits of using GET and POST.  --- Support this podcast: https://anchor.fm/hnasr/support

  Microservices (Explained by Example) Microservices technology is a new pattern of software engineering that has been popularized recently. In this video we will explain what microservices are, their pros and cons by example.  A lot of companies have moved in the early 2010 such as twitter and netflex to the microservices architecture.  Microservices technology is a pattern where you can break down big application into smaller services and what previously is a function call is now a network call GET or POST through HTTP. In order to explain what microservices are, we need to explain how a traditional classical application looks like. Here is an example .. Instagram   View Picture, list comments, likes and Picture and Location.  Picture Likes Comments Picture API (Thumbnails)  Likes API  Comments API Most popular comments Pros: Polyglot architecture  Easy scaling for microservices that needs scaling.  Better Team management, each microservice is a team Easier to innovate certain areas. Each microservice can p