Caveat emptor ( buyer beware)

Posted on June 1, 2009
Filed Under General | Leave a Comment

Have you seen those adverts on the web or in the internet mags advertising server co-location. Co-location is where you pay a company to place your server on the internet in a data center. You pay a monthly or fee and you may sometimes a setup fee. Just like a mobile phone, different tarrifs are available, depending on your requirements. These are the key variables which will affect your pricing.

Bandwidth
Size, 1U, 2U etc
Additional IP addressing
Physical Firewall
**Power Consumption

The reason I have placed an asterisk next to power consumption is because this is a key area where you may get stung. Most hosting providers will have an introductory tarrif which will allow your server to consume 0.4a to 0.5a of power. If your server is pulling more than 0.4a when a measurement is taken, You will be charged extra for going over your allowance,

Seems fair at first glance, power & cooling is expensive after all. However , how many servers draw 0.5amps. You are hosting a server designed to serve hundreds of people, lots of ram and redundant power supplies and hard discs. Yet you have an allowance of 0.5amps. To put this in perspective, I have seen my little Fujitsu sub-note book draw 0.3amps when on charge.

Perhaps I should co-locate my sub-notebook.

The point of this posting is to let you be aware that the headline tarrifs you see for server hosting will not always be what you will pay. It is very important to know your hardware and how much power it use’s at idle, and also on full load. That £45 per month tarrif could end up costing you £75 per month because you did not do your homework.

Caveat emptor

Sockstress is able to cause internet meltdown

Posted on October 4, 2008
Filed Under IT News | Leave a Comment

A rather dangerous security flaw which can cause major havoc on the ability to deliver internet services has been discovered. A team of security researchers have discovered a security flaw in the protocol called TCP. TCP is the blood that flows through the internet. Without TCP the internet would not function as we know it.

To investigate this security flaw, an application called Sockstress has been created. This application has the ability to crash routers, Firewalls, Web Servers, Windows Servers and even Linux servers. This is a serious cross platform flaw which affects any internet device which offers internet based services. Even your small webserver sitting behind your broadband router is affected.

It works by causing what is known as a DOS (Denial of Service ) attack. This means the server will no longer be able to function or offer websites, Email or any internet based services.

It works by causing the internet server to consume large amounts of resources, and then it runs out of resources and stops working. Resources are things like Memory and Disc space. Every connection that is made to a internet servers requires resources. When a new connection is made , the servers will allocate resources for that connection. The more connections that are made, the more resources are allocated.

Sockstress creates connections to the internet server, then does nothing with them. The internet server then keeps asking “Can you use the connection now ?” and the answer is always no. And at the same time new connections are being made, and the process gets repeated. Eventually the server runs out of resources to offer to real customers, and it dies.

Think of it like this.

A few people telephone a restaurant and reserve a table. The restaurant reserves the table for that person. These people keep doing this over a period of time pretending to be different people. The restaurant reserves all it’s tables, calls in extra staff, cancels staff vacations and starts refusing real customers because all tables are reserved.

These trickster people who have made these reservations do not turn up and the restaurant tries to contact these people to see what’s happening. Some people can be contacted and they insist that they are coming, please do not unreserve my table.

During all this, the restaurant is no longer accepting reservations from real customers. The real customers have been denied service. Hence the term DOS “Denial Of Service” attack

This is a very simplistic view, but it conveys the principal of how the attack works.

I’m sure a workaround will be created soon, However at the moment we don’t have one, and the internet is as risk.

http://www.t2.fi/2008/08/27/jack-c-louis-and-robert-e-lee-to-talk-about-new-dos-attack-vectors/

NYSE depends on Linux

Posted on October 1, 2008
Filed Under Open Source | Leave a Comment

The New York Stock Exchange depends on Red Hat Linux to perform. They use Linux for trading systems and they purchase support from Redhat. Key fetures looked for are:

Speed
Reliability
Cost
Flexibility

Another day in the office !

Posted on September 11, 2008
Filed Under Humor | Leave a Comment

The Great Office War from Runawaybox on Vimeo.

Magento Open Source Ecommerce

Posted on September 4, 2008
Filed Under Open Source | Leave a Comment

I have recently come across a very promising ecommerce product called Magento. The current version is 1.14. At the time of writing this post, Magento is just over 1 year old. It is still a very young product and show’s great promise. It is designed using current PHP coding standards, and is based around the Zend PHP development framework. It also has a very clean user interface which makes it very nice to use.

The code and the user front end are separated from each other, this makes template development so much easier. Some of key areas still need development.

Performance can be a problem, and a dedicated host with a PHP bytecode cache is ideal
No support file based down-loadable products like software or music
Poor support for bulk importing of products, if you have product set of several thousand products, It can take several hours to import data

I actually quite like the product and will be watching it mature. In fact when I get more time , I would like to contribute to it’s development. However as it is now, I would not recommended for a very busy or a site with a large product set.