Ubuntu server out of box is not optimized to make full use of available hardware. This means “out-of-box” setup might fail under high load.

So we need to tweak system configuration for maximum concurrancy.

easyengine

What limits the maximum number of connections on a Linux server?

serverfault

function mean(numbers) {
    // mean of [3, 5, 4, 4, 1, 1, 2, 3] is 2.875
    var total = 0,
        i;
    for (i = 0; i < numbers.length; i += 1) {
        total += numbers[i];
    }
    return total / numbers.length;
}

function median(numbers) {
    // median of [3, 5, 4, 4, 1, 1, 2, 3] = 3
    var median = 0,
        numsLen = numbers.length;
    numbers.sort();
    if (numsLen % 2 === 0) { // is even
        // average of two middle numbers
        median = (numbers[numsLen / 2 - 1] + numbers[numsLen / 2]) / 2;
    } else { // is odd
        // middle number only
        median = numbers[(numsLen - 1) / 2];
    }
    return median;
}

function mode(numbers) {
    // as result can be bimodal or multimodal,
    // the returned result is provided as an array
    // mode of [3, 5, 4, 4, 1, 1, 2, 3] = [1, 3, 4]
    var modes = [],
        count = [],
        i,
        number,
        maxIndex = 0;
    for (i = 0; i < numbers.length; i += 1) {
        number = numbers[i];
        count[number] = (count[number] || 0) + 1;
        if (count[number] > maxIndex) {
            maxIndex = count[number];
        }
    }
    for (i in count) if (count.hasOwnProperty(i)) {
        if (count[i] === maxIndex) {
            modes.push(Number(i));
        }
    }
    return modes;
}

function range(numbers) {
    // range of [3, 5, 4, 4, 1, 1, 2, 3] is [1, 5]
    numbers.sort();
    return [numbers[0], numbers[numbers.length - 1]];
}

sitepoint

A curated list of awesome tutorials and other resources for the Slim micro framework.

xssc/awesome-slim

A curated list of amazingly awesome PHP shiny things

ziadoz/awesome-php

Clean Code PHP

jupeter/clean-code-php

Modern PHP Cheat sheet

modern-php-cheatsheet

Secure PHP Web Applications and Prevent Attacks?

php-security-issues

fsck

Since most of the time you can fix broken file systems with an fsck, try..

$ sudo fsck /dev/mmcblk0p2

...if this fails continue here

10 Linux Fsck Command Examples to Check and Repair Filesystem