The London Stock Exchange has agreed to acquire MillenniumIT, and will be replacing its TradElect and Infolect systems with the MillenniumIT trading system. TradElect is based on Windows Server and .NET, and was created by Microsoft and Accenture. Microsoft used to use the LSE’s system as a showcase for .NET scalability, but while it proved that .NET can work for large systems, the LSE suffered an outage in September 2008 that was rumoured to be the fault of TradElect.

I don’t know much about MillenniumIT but note that the company is a partner with Sun and Oracle and that the MillenniumIT Exchange brochure [pdf] states:

Operating System: UNIX or Linux Database: Oracle

As Brian Bryson of IBM/Rational observes, it is short-sighted to lay the blame on the platform. Nevertheless, considering the high profile of this system and Microsoft’s active involvement it is at least an embarrassment.

The mitigation for Microsoft is that .NET has less to prove these days. Even if running a system as large and performance-critical as the London Stock Exchange was a step too far, particularly for Server 2003 and (apparently) SQL Server 2000, that doesn’t rule out Microsoft’s technology for more usual workloads; and there are improvements in Server 2008 and SQL Server 2008.

Still, I’d love to know more about why the LSE is abandoning TradElect and what the lessons are for those designing and implementing systems at this level.

The problems with TradElect are thoroughly debated in the comments here.

Update: Microsoft’s LSE Case Study from 2006 is here.

I have also received the following statement from a Microsoft spokesperson: