Did you know that keeping two multi-core systems in lock-step was hard? No, neither did I. But apparently it is - but one company claims to have gone and done it.
Stratus is well-known for its high availability servers - these work by putting a pair of servers side-by-side and keeping everything, from the CPU downwards, in complete lockstep. The idea is that if any piece of the hardware chain fails, whether CPU, memory, hard disk or whatever, there's near-instant failover to the other server and zero downtime.
Disclaimer: I don't have one but I've met Stratus customers who do and they swear by them and are very loyal.
Just over a year ago, Stratus launched software called Avance that is claimed to do much the same thing, only in software but using standard server hardware. Marathon is a company that, with its EverRun product line, does something similar.
What Stratus now reckons it's managed to do is to produce a continuously available platform on servers using symmetric multi-processing. In other words, with an off-the-shelf multi-core machine, you will soon be able to keep it in lockstep at the CPU level with another multi-core server using just software.
The company reckons that no-one else is doing this - Avance currently keeps only a single core in lockstep - that it took 18 months of labs work to produce, and that it has patented the process. But you'll have to wait a while before you see it in product form. With a claimed three years' lead over the competition, Stratus reckons that waiting until 2011 (or maybe a bit sooner) before launching a product still leaves it in front.