Archive for July, 2010

July 29, 2010

Facebook scales to 500 million users

July 29th 2010 Posted to Geekery

A few of the big numbers Facebook deals with:
* 500 million active users
* 100 billion hits per day
* 50 billion photos
* 2 trillion objects cached, with hundreds of millions of requests per second
* 130TB of logs every day

Remember, there are only three numbers in computer science: 0, 1, and n. This is what scaling horizontally is – break out the infrastructure so that it’s trivial to add another instance of, say, a database server.

Read the full note from the Facebook engineering team: http://www.facebook.com/note.php?note_id=409881258919

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July 27, 2010

Hacked MediaTemple sites inserting javascript malware

July 27th 2010 Posted to Geekery

One of my friend’s sites recently had some javascript hacked, which cunningly hid the contents of what it wrote to the screen so that searching through the files with normal means didn’t even show what files were affected.

So here’s a script which shows possibly hacked files. Assuming you have ssh access to your server, save it as check_for_hacked_js.sh and then chmod 755 it. To run it, type:

./check_for_hacked_js.sh

Once it’s done, check the contents of hacked.txt – and you’ll see all files which have possibly been hacked.

#!/bin/bash

# This script scearches through all files on the server for
# a certain string which writes some malware javascript to
# client browsers, and then saves the results in a file
# for inspection.

# Written by Roger Saner on 2010.07.15

grep -ri "document.write(unescape" * > hacked.txt

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