serac

/*
 * See LICENSE for licensing and NOTICE for copyright.
 */
package edu.vt.middleware.app;

import java.io.File;
import java.security.*;
import java.util.ArrayList;
import java.util.List;
import java.util.function.Predicate;

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?

joewiz

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

jjfiv

// BSD License (http://lemurproject.org/galago-license)
package org.lemurproject.galago.utility.json;

public class JSONUtil {
  public static String escape(String input) {
    StringBuilder output = new StringBuilder();

    for(int i=0; i<input.length(); i++) {
      char ch = input.charAt(i);
      int chx = (int) ch;

staltz

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.

---

DonDebonair

import java.math.BigInteger;

public final class IbanTest {

    public static final int IBANNUMBER_MIN_SIZE = 15;
    public static final int IBANNUMBER_MAX_SIZE = 34;
    public static final BigInteger IBANNUMBER_MAGIC_NUMBER = new BigInteger("97");

    public static boolean ibanTest(String accountNumber) {
        String newAccountNumber = accountNumber.trim();

ndarville

Business Models

Advertising

Models	Examples
Display ads	Yahoo!
Search ads	Google

oodavid

Restore MySQL from Amazon S3

This is a hands-on way to pull down a set of MySQL dumps from Amazon S3 and restore your database with it

Sister Document - Backup MySQL to Amazon S3 - read that first

1 - Set your MySQL password and S3 bucket, make a temp dir, get a list of snapshots

# Set our variables

export mysqlpass="ROOTPASSWORD"