Service Level Agreements (SLAs) are a critical part in preparing for the worst when it comes to cloud reliability. SLAs clearly spell out who is responsible for what should anything go array. While these agreements are designed to answer any questions customers may have about what happens in the event of any downtime, the fine print can be a bit daunting.
So what exactly is lurking in the fine print of some of these agreements?
Though not technically a service level agreement, Oracle's Cloud Enterprise Hosting and Delivery Policies website may have some alarming news for customers who host workloads within its cloud service. Barb Darrow of Fortune has found that Oracle's cloud service has scheduled maintenance for about 10 hours every month which could result in downtime for some users.
Ten hours a month is nothing to sneeze at - that essentially translates to a full working-day of downtime during any given month. It seems that the scheduled maintenance window is on Fridays, "initiating at approximately 20:00 data center local time." According to Darrow:
"For certain applications in some businesses, it’s not unusual to build six or seven hour scheduled maintenance windows into the weekend or overnight. There are some jobs, for example, that can be slated easily around maintenance. A payroll system, can go offline over the weekend to update tax tables, without a lot of angst. But, for a global high-traffic retailer, a payment system going offline over the weekend is unacceptable, said an IT consultant in the Washington D.C. area who works with Oracle government accounts and who requested anonymity because of those relationships."
So how much downtime is too much when it comes to cloud computing? SLAs that promised 99.9 percent uptime are still prevalent, but just how accurate are they? If cloud services are expected to be up all the time, what kind of time does that leave for maintenance? If you have answers to any of these questions, please leave your thoughts in the comments.