The Backend Engineering Show with Hussein Nasser

HSTS or HTTP Strict Transport Security is a mechanism to force clients to communicate in HTTPS with a web server if both support this protocol.  

In this podcast, I talk through this tech.

Database engines or storage engines or sometimes even called embedded databases is software library that a database management software uses to store data on disk and do CRUD (create update delete)

Embedded means move everything in one software no network client server.

In this video I want to go through the few popular database engines, explain the differences between them and finally I want to spin up a database and change its engine and show the different features on each engine

Timecodes

What is a database Engine 3:00

myISAM 9:43

Aria 16:30

InnoDB 19:00

XtraDB 25:30

LevelDB 27:40

RocksDB 34:00

SQLite 38:11

BerkelyDB 42:00

Demo! 47:11

Cards

ACID 4:30

mysql/javascript 56:17

Resources

https://youtu.be/V_C-T5S-w8g

https://mariadb.com/kb/en/library/changes-improvements-in-mariadb-102/

https://mariadb.com/kb/en/library/why-does-mariadb-102-use-innodb-instead-of-xtradb/

https://github.com/facebook/rocksdb/wiki/Features-Not-in-LevelDB

https://mariadb.com/kb/en/library/aria-storage-engine/

Best of MyISAM and InnoDB

What is the performance impact of using CHAR vs VARCHAR on a fixed-size field?

MySQL :: MySQL 8.0 Reference Manual :: 15.6.2.1 Clustered and Secondary Indexes

Why Uber Engineering Switched from Postgres to MySQL | Uber Engineering Blog

Database Sharding Crash Course (with Postgres examples)

Database sharding is process of segmenting the data into partitions that are spread on multiple database instances to speed up queries and scale the system.

What is sharding?

sharing key / partition key

Consistent Hashing

Horizontal partitioning vs Sharding

Example

Pros and cons

What is Sharding? 1:30

Consistent Hashing 4:50

Horizontal partitioning vs Sharding 7:36

Example 8:45

Spin up Docker Postgres Shards 10:02

Write to the shard 17:25

Read from the Shard 39:20

Pros & Cons 51:10

Cards

Postgres pgadmin Docker 8:54

Postgres Javascript 18:18

URL vs Query param 22:30

CORS 29:30

sql injection 42:40

Source Code

https://github.com/hnasr/javascript_playground/tree/master/sharding

Docker commands (including pgadmin)

https://github.com/hnasr/javascript_playground/blob/master/sharding/shards/commands.txt

Dockerfile & init.sql

https://github.com/hnasr/javascript_playground/tree/master/sharding/shards

Horizontal partitioning vs Sharding

HP same database instance so you can still join

sharding across instances (different server)

Pros

Extreme scale rdbms

Optimal and Smaller index size

Cons

Transactions across shards problem

Rollbacks

Schema changes

Complex client (aware of the shard)

Joins

Has to be something you know in the query

Example

URL shortener

create table

CREATE TABLE public.test1

(

id serial NOT NULL primary key,

url text,

url_id character(5)

)

Spin up 3 instances

p1

P2

P3

post

get

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.

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

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

RabbitMQ

RabbitMQ is an open source distributed message queue written in Erlang and supports many communication protocols. It was trying to solve the spaghetti 🍝 mesh architecture where every client is communicating with other client in System by introducing an extra layer in the middle.

(slide)

In this video we will explain basic components of RabbitMQ Such as AMQP, channel, queue, publisher, consumer and some stuff, we will also learn how to spin up a RabbitMQ server and we will finally write some code to develop a publisher client that post messages to RabbitMQ. We will also write the consumer piece which will be the code that reads rabbitMQ. Finally I will talk about my personal thoughts on this tech.

timecodes

components 2:00

spin up docker rabbit 8:30

Write a Publisher client NodeJs 11:00

Write a consumer client NodeJs 20:30

my thoughts 33:50

Source Code: https://github.com/hnasr/javascript_playground/tree/master/rabbitmq

Example

Schedule async job

Exchange

Queues

Publisher

Consumer

AMQP

Channel

Connection

HTTP

AMQP

Uses Channels and Queues

Multiples channels into one connections

docker run --name rabbitmq -p 5672:5672 -d rabbitmq

docker run --name rabbitmq -p 5672:5672 -p 15672:15672 -d rabbitmq:3-management

HTTP

fetch("http://localhost:15672/api/vhosts”, {headers: {"Authorization" : `Basic ${btoa('guest:guest')}`}}).then(a=>a.json()).then(console.log)

fetch("http://localhost:15672/api/channels", {headers: {"Authorization" : `Basic ${btoa('guest:guest')}`}}).then(a=>a.json()).then(console.log)

fetch("http://localhost:15672/api/queues", {headers: {"Authorization" : `Basic ${btoa('guest:guest')}`}}).then(a=>a.json()).then(console.log)

https://www.squaremobius.net/amqp.node/channel_api.html#channel_bindExchange

https://www.rabbitmq.com/tutorials/tutorial-three-javascript.html