Ensuring that our service is available for use whenever our customers need it is our top priority. There are two parts to this: reducing unscheduled downtime (outages) and also reducing the scheduled variety.
Beginning with the unscheduled variety, in the last 12 months we’ve achieved a headline availability of 99.997% (this is 14 minutes). In reality we did a little better than that:
9 minutes was a DNS issue with our provider: they suffered a ‘DDoS’ attack which took some time to mitigate – because DNS results are cached most users would not have noticed this unless they were attempting to login at the time.
5 minutes was due to four network ‘blips’ of between 1 and 2 minutes, two of which were between 1AM and 2AM and due to out of hours engineering work by a third-party. Because of the client-server nature of the Workbooks Desktop few users will have noticed these either.
Playing a little loose with the numbers, if you consider the 6am – 12 midnight period and exclude the DNS issue which affected less than 5% of our users then we delivered 99.9995% availability: I have to admit this will be tough to maintain.
The other variety is scheduled downtime: this happens when we are upgrading our systems, it’s planned and announced in advance and done outside working hours. We also look to reduce this as much as possible – most upgrades now take just a few minutes. Any scheduled downtime is alerted to our customers within Workbooks CRM.