Skype outage due to bad log-in mechanisms

Posted on in Categories Beyond nixCraft, High performance computing, Networking last updated August 20, 2007

On 16th August 2007, the Skype peer-to-peer network became unstable and suffered a critical disruption. According to official blog post it was windows update service:

The disruption was triggered by a massive restart of our users’ computers across the globe within a very short timeframe as they re-booted after receiving a routine set of patches through Windows Update.

The high number of restarts affected Skype’s network resources. This caused a flood of log-in requests, which, combined with the lack of peer-to-peer network resources, prompted a chain reaction that had a critical impact.

There was also news about some Russian crackers brought down the service. Skype has denied this rumor and assured that no malicious activities were attributed or users’ security was in danger, at any point.

This incident clearly provides few hints:
(a) Microsoft dominates PC desktop market.
(b) Application code can bring down entire network, so always consider HA ( High-Availability networking and storage) along with app code
(c) Skype does not blame Microsoft. It was their own code

MySQL Proxy Load balancing and Failover Tutorial

Posted on in Categories CentOS, Debian Linux, Download of the day, High performance computing, Howto, Linux, Monitoring, MySQL, RedHat/Fedora Linux, Suse Linux, Tuning, Ubuntu Linux, UNIX last updated August 10, 2007

MySQL Proxy is a simple and new program that sits between your client and MySQL server(s) that can monitor, analyze or transform their communication. Its flexibility allows for a wide variety of use cases, including:
a) Load balancing
b) Failover
c) Query analysis
d) Query filtering and modification
e) and many more…

MySQL Proxy tutorial

Oreilly has published a nice tutorial using MySQL proxy application:

MySQL Proxy is a lightweight binary application standing between one or more MySQL clients and a server. The clients connect to the Proxy with the usual credentials, instead of connecting to the server. The Proxy acts as man-in-the-middle between client and server.

In its basic form, the Proxy is just a redirector. It gets an empty bucket from the client (a query), takes it to the server, fills the bucket with data, and passes it back to the client.

If that were all, the Proxy would just be useless overhead. There is a little more I haven’t told you yet. The Proxy ships with an embedded Lua interpreter. Using Lua, you can define what to do with a query or a result set before the Proxy passes them along.

MySQL Proxy Load balancing and Failover Tutorial - Logo

Download MySQL proxy

You can download MySQL proxy here