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While Amazon Web Services (AWS) has established itself as a top contender in the cloud computing market, it’s not without its challenges and misconceptions. Get expert insight into the most common and pressing questions regarding AWS management, monitoring, costs, benefits, limitations and more.
An AWS user can increase or decrease instance capacity as needed within minutes using the Amazon EC2 web interface or an application programming interface. A developer can code an application to scale instances automatically with AWS Auto Scaling. A developer can also define an Auto Scaling policy and group to manage multiple instances at once.
To use EC2, a developer creates an Amazon Machine Image (AMI) containing an operating system, application programs and configuration settings. The AMI is then uploaded to the Amazon Simple Storage Service (Amazon S3) and registered with Amazon EC2, creating an AMI identifier. Once this has been done, the subscriber can requisition virtual machines on an as-needed basis.
Data only remains on an EC2 instance while it is running, but a developer can use an Amazon Elastic Block Store volume for an extra level of durability and Amazon S3 for EC2 data backup.
VM Import/Export allows a developer to import on-premises virtual machine images to Amazon EC2, where they are turned into instances.
Amazon EC2 instance types
Amazon EC2 provides different instance types, sizes and pricing structures designed for different computing and budgetary needs. In addition to general purpose instances, Amazon EC2 offers an instance type for compute, memory, accelerated computing and storage-optimized workloads. AWS limits how many instances a user can run in a region at a time, depending on the type of instance. Each instance type comes with different size options corresponding to the CPU, memory and storage needs of each enterprise.
On-Demand Instances allows a developer to create resources as needed and to pay for them by the hour. Reserved Instances (RIs) provides a price discount in exchange for one and three-year contract commitments; a developer can also opt for a convertible RI, which allows for the flexibility to change the instance type, operating system or tenancy. There’s also an option to purchase a second-hand RI from the Amazon EC2 Reserved Instances Marketplace. A developer can also submit a bid for spare Amazon EC2 capacity, called Spot Instances, for a workload that has a flexible start and end time. If a business needs dedicated physical server space, a developer can opt for EC2 Dedicated Hosts, which charge hourly and let the business use existing server-bound software licenses, including Windows Server and SQL Server.