Financial Market Data Web Services – Xignite Blog

In a recent post, Dan Farber and Larry Dignan
talked about the fact that there is still much ground to cover before
all major Internet properties will provide the "five nines" (99.9999%
availability). Their key point was that today’s Internet services are not "ready" for the massive wave of utility computing ahead and that more money and intelligence needed to be thrown at those problems.

Their post talks about "web services" in more general
consumer sense than ours (where we mean XML web services), but the comment certainly applies. With more than 300 clients in 25 countries and upwards of 500 million
web service requests a months, our web services are powering more and
more mission-critical business processes buried deep inside the core
fabric of our clients’ business. This of course raises the question of the availability of those services and what’s right given the maturity of the market.

Web services as a "computing utility platform" for business are at least 10 years behind the web as a utility platform for consumers. That wave started in 2005 while the web goes back to 1995. So it’s normal to expect a lower level of maturity. Our experience to date has been that clients and prospective users have been more and more sensitive to availability issues but that guaranteeing "three nine" (99.9% availability) meets all current business needs. I expect that the market will be requesting another "nine" every year for the next 4 years (2008->99.99%, 2009->99.999%, 2010-> 99.9999% and maybe more).

There is one key reason for that. Few of our client business processes run themselves in a "fine nine" mode. Many processes are mission critical but they are mission-critical once or several times a day, giving plenty of time for retries and recovery. For instance, one of the world’s largest corporate lenders gets some interest rates information from us. This info is used to feed some homegrown systems that decide how much interest corporate clients gets charge for tens of billions of dollars in corporate loans. That’s mission critical. But the process runs once a day (replacing an old unreliable manual process). As long as our system is up within a 1/2 hour timeframe every day, all is well. In truth, we achieve more than 99.99% availability, with many monthly periods at 100% (we have been publishing availability data on our site since 2004. You can find it here). But it’s almost irrelevant to this client.

The key is to map the service level to the needs. Why going to the trouble of providing
99.999% availability if your clients don’t care at all or don’t care yet? Running redundant data centers is extremely expensive and difficult to do for an emerging company. Your clients probably want you to spend your money doing other things firsts. But once they begin asking for more "nines", you’d better get moving.

And so we are planning for our redundant data center–which we will need to get to the "five nines".