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var amqp = require('amqplib/callback_api');

// if the connection is closed or fails to be established at all, we will reconnect
var amqpConn = null;
function start() {
  amqp.connect(process.env.CLOUDAMQP_URL + "?heartbeat=60", function(err, conn) {
    if (err) {
      console.error("[AMQP]", err.message);
      return setTimeout(start, 1000);
    }

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The introduction to Reactive Programming you've been missing

(by @andrestaltz)

---

This tutorial as a series of videos

If you prefer to watch video tutorials with live-coding, then check out this series I recorded with the same contents as in this article: Egghead.io - Introduction to Reactive Programming.

---

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Update Homebrew’s package database.

brew update

To install the MongoDB binaries, issue the following command in a system shell:

brew install rabbitmq

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Using Docker and docker-compose to manage Apache Airflow on mac

Using our beloved docker and docker-compose, we can very quickly bring up an Apache Airflow instance on our mac.

Contents of docker-compose.yml

About the only thing you need to customize in this docker-compose.yml file is the volumes section. This will tell docker to map the given directory containing your Airflow DAGs/plugins to container file system.

version: '3'
services:

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check host localhost with address 127.0.0.1
        start "/sbin/start myapp"
        stop "/sbin/stop myapp"
        if failed port 3000 protocol HTTP
                request /
                with timeout 5 seconds
                then restart

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const http = require('http');
const express = require('express');
const redis = require('redis');
const { RateLimiterRedis } = require('rate-limiter-flexible');
const redisClient = redis.createClient({
  enable_offline_queue: false,
});

const maxWrongAttemptsByIPperMinute = 5;
const maxWrongAttemptsByIPperDay = 100;

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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.

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PSQL

Magic words:

psql -U postgres

Some interesting flags (to see all, use -h or --help depending on your psql version):

• -E: will describe the underlaying queries of the \ commands (cool for learning!)
• -l: psql will list all databases and then exit (useful if the user you connect with doesn't has a default database, like at AWS RDS)

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# install needed libraries
sudo yum install texinfo libXpm-devel giflib-devel libtiff-devel libotf-devel

# compile autoconf
cd /tmp
wget ftp://ftp.gnu.org/gnu/autoconf/autoconf-2.68.tar.bz2
tar xjvf autoconf-2.68.tar.bz2
cd autoconf-2.68/
./configure && make && sudo make install

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/**
 * Module dependencies
 */

var express = require('express');
var fs = require('fs');
var mongoose = require('mongoose');
var Schema = mongoose.Schema;

// img path