Cloudlet is the smallest Bitmana infrastructure component. It is a special resource unit that equals to 128 MiB of RAM and 400 MHz of CPU power simultaneously. Such high granularity of resources allows the system to allocate the exactly required capacity for each instance in the environment. This ensures the truly fair usage-based pricing, so that only the really consumed resources are being paid.
There are two types of cloudlet:
- Reserved Cloudlets are fixed amount of resources reserved in advance and charged irrespective of the actual usage. Reserved cloudlets are cheaper than dynamic and recommended to be used when the application load is permanent.
- Dynamic Cloudlets are added and removed automatically according to the amount of resources required by your application (assigned when load goes up and removed as soon as it drops down). Dynamic cloudlets are recommended to be used for applications with variable load or when it cannot be predicted in advance, ensuring the truly usage-based charging model. In such a way, so that you pay based on your actual resource usage within the scaling limit.
Note: When calculating cloudlet usage, the system considers only the larger of RAM or CPU usage per hour (not both combined). E.g. if during one hour your average CPU usage is 2400 MHz (6 cloudlets), and your peak RAM usage is 1024 MiB (8 cloudlets), you pay for 8 cloudlets – not the combined total (14 cloudlets).
Both reserved and dynamic cloudlets functionality provides auto discounts for the usage volume - the more is used, the cheaper is the base price.