vasanthk

System Design Cheatsheet

Picking the right architecture = Picking the right battles + Managing trade-offs

Basic Steps

1. Clarify and agree on the scope of the system

• User cases (description of sequences of events that, taken together, lead to a system doing something useful)
  • Who is going to use it?
  • How are they going to use it?

denji

Moved to git repository: https://github.com/denji/nginx-tuning

NGINX Tuning For Best Performance

For this configuration you can use web server you like, i decided, because i work mostly with it to use nginx.

Generally, properly configured nginx can handle up to 400K to 500K requests per second (clustered), most what i saw is 50K to 80K (non-clustered) requests per second and 30% CPU load, course, this was 2 x Intel Xeon with HyperThreading enabled, but it can work without problem on slower machines.

You must understand that this config is used in testing environment and not in production so you will need to find a way to implement most of those features best possible for your servers.

akabe1

/*  Android ssl certificate pinning bypass script for various methods
	by Maurizio Siddu
	
	Run with:
	frida -U -f <APP_ID> -l frida_multiple_unpinning.js [--no-pause]
*/

setTimeout(function() {
	Java.perform(function() {
		console.log('');

LeCoupa

/* *******************************************************************************************
 * THE UPDATED VERSION IS AVAILABLE AT
 * https://github.com/LeCoupa/awesome-cheatsheets
 * ******************************************************************************************* */


// 0. Synopsis.
// http://nodejs.org/api/synopsis.html

soheilhy

Virtual Hosts on nginx (CSC309)

When hosting our web applications, we often have one public IP address (i.e., an IP address visible to the outside world) using which we want to host multiple web apps. For example, one may wants to host three different web apps respectively for example1.com, example2.com, and example1.com/images on the same machine using a single IP address.

How can we do that? Well, the good news is Internet browsers

jahe

// Enable component-scanning and auto-configuration with @SpringBootApplication Annotation
// It combines @Configuration + @ComponentScan + @EnableAutoConfiguration
@SpringBootApplication
public class FooApplication {
  public static void main(String[] args) {
    // Bootstrap the application
    SpringApplication.run(FooApplication.class, args);
  }
}

alirobe

### 
###
### UPDATE: For Win 11, I recommend using this tool in place of this script: 
### https://christitus.com/windows-tool/
### https://github.com/ChrisTitusTech/winutil
### https://www.youtube.com/watch?v=6UQZ5oQg8XA
### iwr -useb https://christitus.com/win | iex
###
###

munificent

#include <time.h> //  Robert Nystrom
#include <stdio.h> // @munificentbob
#include <stdlib.h> //     for Ginny
#define  r return    //    2008-2019
#define  l(a, b, c, d) for (i y=a;y\
<b; y++) for (int x = c; x < d; x++)
typedef int i;const i H=40;const i W
=80;i m[40][80];i g(i x){r rand()%x;
}void cave(i s){i w=g(10)+5;i h=g(6)
+3;i t=g(W-w-2)+1;i u=g(H-h-2)+1;l(u

cubehouse

// start with:
//   frida -U -l pinning.js -f [APP_ID] --no-pause

Java.perform(function () {
    console.log('')
    console.log('===')
    console.log('* Injecting hooks into common certificate pinning methods *')
    console.log('===')

    var X509TrustManager = Java.use('javax.net.ssl.X509TrustManager');

debasishg

General Background and Overview

1. Probabilistic Data Structures for Web Analytics and Data Mining : A great overview of the space of probabilistic data structures and how they are used in approximation algorithm implementation.
2. Models and Issues in Data Stream Systems
3. Philippe Flajolet’s contribution to streaming algorithms : A presentation by Jérémie Lumbroso that visits some of the hostorical perspectives and how it all began with Flajolet
4. Approximate Frequency Counts over Data Streams by Gurmeet Singh Manku & Rajeev Motwani : One of the early papers on the subject.
5. [Methods for Finding Frequent Items in Data Streams](http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.187.9800&rep=rep1&t