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On Tue Oct 27, 2015, history.state.gov began buckling under load, intermittently issuing 500 errors. Nginx's error log was sprinkled with the following errors:

2015/10/27 21:48:36 [crit] 2475#0: accept4() failed (24: Too many open files)

2015/10/27 21:48:36 [alert] 2475#0: *7163915 socket() failed (24: Too many open files) while connecting to upstream...

An article at http://www.cyberciti.biz/faq/linux-unix-nginx-too-many-open-files/ provided directions that mostly worked. Below are the steps we followed. The steps that diverged from the article's directions are marked with an *.

1. * Instead of using su to run ulimit on the nginx account, use ps aux | grep nginx to locate nginx's process IDs. Then query each process's file handle limits using cat /proc/pid/limits (where pid is the process id retrieved from ps). (Note: sudo may be necessary on your system for the cat command here, depending on your system.)
2. Added fs.file-max = 70000 to /etc/sysctl.conf

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-- show running queries (pre 9.2)
SELECT procpid, age(clock_timestamp(), query_start), usename, current_query 
FROM pg_stat_activity 
WHERE current_query != '<IDLE>' AND current_query NOT ILIKE '%pg_stat_activity%' 
ORDER BY query_start desc;

-- show running queries (9.2)
SELECT pid, age(clock_timestamp(), query_start), usename, query 
FROM pg_stat_activity 
WHERE query != '<IDLE>' AND query NOT ILIKE '%pg_stat_activity%' 

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Google Script CRUD

By Ryan Aunur Rassyid

Simply create RESTful API with Google Script and store it to Google SpreadSheet like a Pro.

Learn From http://www.androidlabs.info/appscript/crud-operation-on-google-spread-sheet-using-google-app-script-html-jquery/

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<?php

namespace App\Providers;

use App\Models\User;
use App\Observers\UserObserver;
use Illuminate\Support\ServiceProvider;

class AppServiceProvider extends ServiceProvider
{

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Simple automated GIT Deployment using GIT Hooks

Here are the simple steps needed to create a deployment from your local GIT repository to a server based on this in-depth tutorial.

How it works

You are developing in a working-copy on your local machine, lets say on the master branch. Most of the time, people would push code to a remote server like github.com or gitlab.com and pull or export it to a production server. Or you use a service like deepl.io to act upon a Web-Hook that's triggered that service.

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iptables --insert INPUT --protocol tcp --dport 80 --jump ACCEPT
iptables --insert INPUT --protocol tcp --dport 8080 --jump ACCEPT
iptables --table nat --append PREROUTING --in-interface eth0 --protocol tcp --dport 80 --jump REDIRECT --to-port 8080
# run next line to have changes survive reboot
service iptables save

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Simple Guide to setup Golang in your Mac and clone a repo.

Setup Go and workspace

• Download the installer from the page https://golang.org/dl/ and install the package.

Type go in terminal, to verify the installation.

• Create a Go workspace and set GO PATH

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The responsive helpers are to help the developer with writing responsive specs.

All you have to do is, add `responsive_helper.rb` to the spec support directory.

And tag the specs with :mobile, :tablet for mobile and tablet size respectively.

If you don't use any tag, it would render the desktop size.

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OS X Screencast to animated GIF

This gist shows how to create a GIF screencast using only free OS X tools: QuickTime, ffmpeg, and gifsicle.

Instructions

To capture the video (filesize: 19MB), using the free "QuickTime Player" application:

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# TO DO when there is warning message on locales
sudo locale-gen en_US en_US.UTF-8
sudo dpkg-reconfigure locales 
export LC_ALL="en_US.UTF-8"

# Update, upgrade and install development tools:
sudo apt-get update
sudo apt-get -y upgrade
sudo apt-get -y install build-essential git-core libssl-dev libsqlite3-dev curl nodejs nginx libreadline-dev rbenv