The Doppler Quarterly Winter 2018 | Page 29

Per-Hour Price Instances $0.10 M1.small M2.2xlarge M3.xlarge C1.medium C3.large $0.08 $0.06 $0.04 $0.02 $0.00 Oct-08 Oct-09 Oct-10 Oct-11 Oct-12 Oct-13 Oct-14 Oct-15 Figure 2: Price Reductions for Sample EC2 Instances History of Cloud Pricing All three big public cloud vendors (AWS, Microsoft and Google) have histori- cally had different price models for renting virtual servers. Let’s quickly review how they’ve changed over the years: • Amazon started charging by the hour with a 1 hour minimum, and just recently migrated to per-second billing (more on this later). • Microsoft started with billing VMs by the hour, then moved to billing by the minute and now bills by the second, but only for containers and functions. • Google used to charge by the minute with a 10 minute minimum, and now charges by the second with a 1 minute minimum. All public cloud vendors’ hourly rates vary from a few cents to a few dollars depending on how powerful a server you rent. On top of that, every vendor has a different approach to helping clients realize additional cost savings if they rent virtual machines for a long time. Amazon allows you to prepay for capacity by buying reserved instances. If you are going to use a server consistently for a year or more, it makes sense to prepay upfront and save a good chunk of money in the long term. Google’s approach is differ- ent. They automatically give customers discounts based on how long the server is in use. They call this feature a sustained use discount, and it’s a nice, auto- matic way to get a cost break if the server is in use for awhile. Azure also started offering reserved instances recently, but with the added twist that you can cancel them if you want. WINTER 2018 | THE DOPPLER | 27