An elastic instance is a running instance of an elastic image. One elastic instance is created whenever an elastic image is started. Hence, starting one elastic image multiple times, results in the creation of multiple elastic instances. Each time an elastic instance is created, one elastic agent is created on that instance.
Conceptually, an elastic instance can be thought of as a computer. The elastic agent's processes are run on this computer and the elastic image is the boot hard drive. Unlike computers, however, elastic instances are temporary and stateless. When an elastic instance is shut down:
- Any changes that an elastic instance makes to the boot hard drive (e.g. agent log file) will not persist
- Any customisations to the instance itself will also be lost.
The Amazon Elastic Block Store can provide persistent storage for your elastic instances.